SECTION 100.1 – DEFINITIONS AND RULES OF CONSTRUCTION
(a) Rules of Construction.
1. Where the context requires, the singular includes the plural and the plural includes the singular.
2. The use of “and” in a conjunctive provision means that all elements in the provision must be complied with, or must exist to make the provision applicable. Where compliance with one or more elements suffices, or where existence of one or more elements makes the provision applicable, “or” (rather than “and/or”) is used.
3. “Shall” is mandatory and “may” is permissive.
(b) Definitions. Terms, phrases, words and their derivatives in Part 6 shall be defined as specified in Section 100.1.
Terms, phrases, words and their derivatives not found in Section 100.1 shall be defined as specified in the “Definitions” chapters of Title 24, Parts 1 through 5 of the California Code of Regulations. Where terms, phrases, words and their derivatives are not defined in any of the references above, they shall be defined as
specified in Webster’s Third New International Dictionary of the English Language, Unabridged (1961 edition, through the 2002 addenda), unless the context requires otherwise.
ACCA is the Air Conditioning Contractors of America.
ACCA MANUAL J is the Air Conditioning Contractors of America document titled “Manual J – Residential Load Calculation” (ANSI/ACCA 2 Manual J – 2006).
ACCEPTANCE REQUIREMENTS FOR CODE COMPLIANCE is a description of test procedures in the Reference Nonresidential Appendices that includes equipment and systems to be tested, functions to be tested, conditions under which the test shall be performed, the scope of the tests, results to be obtained, and measurable criteria for acceptable performance.
ACCESSIBLE is having access thereto, but which first may require removal or opening of access panels, doors, or similar obstructions.
ADDITION is any change to a building that increases conditioned floor area and conditioned volume. See also “newly conditioned space.” Addition is also any change that increases the floor area and volume of an unconditioned building of an occupancy group or type regulated by Part 6. Addition is also any change that increases the illuminated area of an outdoor lighting application regulated by Part 6.
AGRICULTURAL BUILDING is a structure designed and constructed to house farm implements, hay, grain, poultry, livestock or other horticultural products. It is not a structure that is a place of human habitation, a place of employment where agricultural products are processed, treated or packaged, or a place used by the public.
AIR BARRIER is a combination of interconnected materials and assemblies joined and sealed together to provide a continuous barrier to air leakage through the building envelope that separates conditioned from unconditioned space, or that separates adjoining conditioned spaces of different occupancies or uses.
AIR CONDITIONER is an appliance that supplies cooled and dehumidified air to a space for the purpose of cooling objects within the space.
AIR-COOLED AIR CONDITIONER is an air conditioner using an air-cooled condenser.
AIR-HANDLING UNIT or AIR HANDLER is a blower or fan that distributes supply air to a room, space, or area.
AIR FILTER EQUIPMENT or AIR FILTER DEVICE is air-cleaning equipment used for removing particulate matter from the air.
AIR FILTER MEDIA is the part of the air filter equipment which is the actual particulate removing agent.
AIR-TO-AIR HEAT EXCHANGER is a device which will reduce the heat losses or gains that occur when a building is mechanically ventilated, by transferring heat between the conditioned air being exhausted and outside air being supplied.
AIR-SOURCE HEAT PUMP is an appliance that consists of one or more factory-made assemblies, that includes an indoor conditioning coil, a compressor, and a refrigerant-to-air heat exchanger, and that provides heating and cooling functions.
ALTERATION is any change to a building’s water-heating system, space-conditioning system, lighting system, electrical power distribution system, or envelope that is not an addition. Alteration is also any change that is regulated by Part 6 to an outdoor lighting system that is not an addition. Alteration is also any change that is regulated by Part 6 to signs located either indoors or outdoors. Alteration is also any change that is regulated by Part 6 to a covered process that is not an addition.
ALTERED COMPONENT is a component that has undergone an alteration and is subject to all applicable Standards requirements.
ALTERNATIVE CALCULATION METHODS (ACM) are compliance softwares, or alternative component packages, or exceptional methods approved by the Commission under Section 10-109. ACMs are also referred to as Compliance Software.
ALTERNATIVE CALCULATION METHODS (ACM) APPROVAL MANUAL are the documents establishing the requirements for Energy Commission approval of Compliance Software used to demonstrate compliance with the Building Energy Efficiency Standards for Residential and Nonresidential Buildings currently adopted by the Energy Commission.
ANNUAL FUEL UTILIZATION EFFICIENCY (AFUE) is a measure of the percentage of heat from the combustion of gas or oil which is transferred to the space being heated during a year, as determined using the applicable test method in the Appliance Efficiency Regulations or Section 110.2.
ANNUNCIATED is a type of visual signaling device that indicates the on, off, or other status of a load.
ANSI is the American National Standards Institute.
ANSI C82.6-2005 is the American National Standards Institute document titled “Ballasts for High-Intensity
Discharge Lamps – Methods of Measurement.” (ANSI C82.6-2005)
ANSI/IES RP-16-10 is the document coauthored by the American National Standards Institute and the Illuminating Engineering Society of North America, Recommended Practice titled “Nomenclature and Definitions for Illuminating Engineering”
ANSI Z21.10.3 is the American National Standards Institute document titled “Gas Water Heaters – Volume III,
Storage Water Heaters With Input Ratings Above 75,000 Btu Per Hour,” 2011 (ANSI Z21.10.3-2011/CSA 4.3-
ANSI Z21.13 is the American National Standards Institute document titled “Gas-Fired Low Pressure Steam and Hot Water Boilers,” 2010 (ANSI Z21.13-2010/CSA 4.9-2010).
ANSI Z21.40.4A is the American National Standards Institute document titled “Addenda 1 to ANSI Z21.40.4-
1996/CGA 2.94-M96, Performance Testing and Rating of Gas-Fired, Air Conditioning and Heat Pump Appliances,”
1998 (ANSI Z21.40.4-1998/CGA 2.94A-M98).
ANSI Z21.47 is the American National Standards Institute document titled “Gas-Fired Central Furnaces,” 2006
(ANSI Z21.47-2006/CSA 2.3-2006).
ANSI Z83.8 is the American National Standards Institute document titled “American National Standard/CSA Standard For Gas Unit Heaters, Gas Packaged Heaters, Gas Utility Heaters and Gas-Fired Duct Furnaces,” 2009
(ANSI Z83.8 -2009/CSA 2.6-2009).
APPLIANCE EFFICIENCY REGULATIONS are the regulations in Title 20, Sections 1601 et seq. of the California Code of Regulations.
APPROVED CALCULATION METHOD (See “alternative calculation methods”)
AHRI is the Air-Conditioning, Heating, and Refrigeration Institute.
AHRI 210/240 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Performance Rating of Unitary Air-Conditioning and Air-Source Heat Pump Equipment,” 2008 (ANSI/AHRI Standard 210/240-2008 with
Addenda 1 and 2).
ANSI/AHRI/CSA 310/380 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Standard for Packaged Terminal Air-Conditioners andHeat Pumps (CSA-C744-04),” 2004 (ANSI/AHRI/CSA Standard 310/380-2004)
AHRI 320 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Water-Source Heat Pumps,” 1998 (AHRI Standard 320-1998).
AHRI 325 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Ground Water-Source Heat Pumps,” 1998 (ARI Standard 325-1998).
ANSI/AHRI 340/360 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Performance Rating of Commercial and Industrial Unitary Air-Conditioning and Heat Pump Equipment,” 2007 (ANSI/AHRI Standard 340/360-2007 with Addenda 1 and 2).
ANSI/AHRI 365 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Commercial and Industrial Unitary Air-Conditioning Condensing Units,” 2009 (ANSI/AHRI Standard 365 (I-P)-2009).
ANSI/AHRI 390 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Performance Rating of Single Package Vertical Air-Conditioners and Heat Pumps,” 2003 (ANSI/AHRI Standard 390 (I-P)-2003).
ANSI/AHRI 400 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Liquid to Liquid Heat Exchangers,” 2001 (ANSI/AHRI Standard 400 (I-P)-2001) with addenda 1 and 2.
ANSI/AHRI 460 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Performance Rating
of Remote Mechanical-Draft Air-Cooled Refrigerant Condensers,” 2005 (ANSI/AHRI Standard 460-2005).
AHRI 550/590 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Performance Rating of
Water Chilling Packages Using the Vapor Compression Cycle,” 2011 (AHRI Standard 550/590-(I-P)-2011).
ANSI/AHRI 560 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Absorption Water Chilling and Water Heating Packages,” 2000 (ANSI/AHRI Standard 560-2000).
AHRI 680 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Performance Rating of Residential Air Filter Equipment,” 2009 (ANSI/AHRI Standard 680).
AHRI 1230 is the Air-Conditioning, Heating, and Refrigeration Institute document titled “Performance Rating of Variable Refrigerant Flow (VRF) Multi-Split Air-Conditioning and Heat Pump Equipment,” 2010 (AHRI Standard 1230-2010) with Addendum 1.
ASHRAE is the American Society of Heating, Refrigerating, and Air-conditioning Engineers.
ASHRAE CLIMATIC DATA FOR REGION X is the American Society of Heating, Refrigerating and Air-
Conditioning Engineers document titled “ASHRAE Climatic Data for Region X, Arizona, California, Hawaii and Nevada,” Publication SPCDX, 1982 and “Supplement,” 1994.
ASHRAE HANDBOOK, APPLICATIONS VOLUME is the American Society of Heating, Refrigerating and Air-
Conditioning Engineers document titled “ASHRAE Handbook: Heating, Ventilating, and Air-Conditioning Applications” (2011).
ASHRAE HANDBOOK, EQUIPMENT VOLUME is the American Society of Heating, Refrigerating and Air-
Conditioning Engineers document titled “ASHRAE Handbook: Heating, Ventilating, and Air-Conditioning Systems and Equipment” (2008).
ASHRAE HANDBOOK, FUNDAMENTALS VOLUME is the American Society of Heating, Refrigerating and
Air-Conditioning Engineers document titled “ASHRAE Handbook: Fundamentals” (2009).
ASHRAE STANDARD 52.2 is the American Society of Heating, Refrigerating and Air-Conditioning Engineers document titled “Method of Testing General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size,” 2012 (ANSI/ASHRAE Standard 52.2-2012).
ASHRAE STANDARD 55 is the American Society of Heating, Refrigerating and Air-Conditioning Engineers document titled ” Thermal Environmental Conditions for Human Occupancy,” 2010 (ASHRAE Standard 55-2010).
ASHRAE STANDARD 62.2 is the American Society of Heating, Refrigerating and Air-Conditioning Engineers document titled “Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings,” 2010
(ANSI/ASHRAE Standard 62.2-2010 including ANSI/ASHRAE Addenda b, c, e, g, h, i and l to ANSI/ASHRAE 62.2-2010 published in the 2011 supplement, and ANSI/ASHRAE Addendum j to ANSI/ASHRAE Standard 62.2- 2010 published in March, 2012, and ANSI/ASHRAE Addendum n to ANSI/ASHRAE Standard 62.2-2010 published
in February, 2012).
ASHRAE STANDARD 193 is the American Society of Heating, Refrigerating and Air-Conditioning Engineers
document titled “Method of Test for Determining the Airtightness of HVAC Equipment,” 2010 (ANSI/ASHRAE
ASME is the American Society of Mechanical Engineers.
ASME A17.1/CSA B44 is the American Society of Mechanical Engineers document titled “Handbook on Safety
Code for Elevators and Escalators” 2013 (ASME Standard A17.1/CSAB44-2013).
ASME A112.18.1/CSA B125.1 is the American Society of Mechanical Engineers document titled “Plumbing
Fixture Fittings” 2011 (ASME Standard A112.18.1-2011/CSA B125.1-11).
ASTM is the American Society for Testing and Materials International.
ASTM C55 is the American Society for Testing and Materials document titled “Standard Specification for Concrete
Brick,” 2014 (ASTM C55-14).
ASTM C177 is the American Society for Testing and Materials document titled “Standard Test Method for Steady-
State Heat Flux Measurements and Thermal Transmission Properties by Means of the Guarded-Hot-Plate
Apparatus,” 2013 (ASTM C177-13).
ASTM C272 is the American Society for Testing and Materials document titled “Standard Test Method for Water
Absorption of Core Materials for Structural Sandwich Constructions,” 2012 (ASTM C272-12).
ASTM C335 is the American Society for Testing and Materials document titled “Standard Test Method for Steady-
State Heat Transfer Properties of Horizontal Pipe Insulation,” 2010 (ASTM C335-10).
ASTM C518 is the American Society for Testing and Materials document titled “Standard Test Method for Steady-
State Thermal Transmission Properties by Means of the Heat Flow Meter Apparatus,” 2010 (ASTM C518-10).
ASTM C731 is the American Society for Testing and Materials document titled “Standard Test Method for
Extrudability, After Package Aging of Latex Sealants,” 2010 (ASTM C731-10).
ASTM C732 is the American Society for Testing and Materials document titled “Standard Test Method for Aging
Effects of Artificial Weathering on Latex Sealants,” 2006 (ASTM C732-06 (2012).
ASTM C836 is the American Society of Testing and Materials document titled, “Standard Specification for High
Solids Content, Cold Liquid-Applied Elastomeric Waterproofing Membrane for Use with Separate Wearing Course,”
2012 (ASTM C836/C836M-12).
ASTM C1167 is the American Society for Testing and Materials document titled “Standard Specification for Clay
Roof Tiles,” 2011 (ASTM C1167-11).
ASTM C1371 is the American Society for Testing and Materials document titled “Standard Test Method for
Determination of Emittance of Materials Near Room Temperature Using Portable Emissometers,” 2010 (ASTM
ASTM C1492 is the American Society for Testing and Materials document entitled “Standard Specification for
Concrete Roof Tile,” 2009 (ASTM C1492-03(2009)).
ASTM C1549 is the American Society for Testing and Materials document entitled, “Standard Test Method for
Determination of Solar Reflectance Near Ambient Temperature Using a Portable Solar Reflectometer,”2014 (ASTM
C1549- 09 (2014).
ASTM C1583 is the American Society of Testing and Materials document titled, “Standard Test Method for Tensile
Strength of Concrete Surfaces and the Bond Strength or Tensile Strength of Concrete Repair and Overlay Materials
by Direct Tension (Pull-off Method),” 2013 (ASTM C1583/c1583M-13).
ASTM D448 is the American Society for Testing and Materials document titled, “Standard Classification for Sizes
of Aggregate for Road and Bridge Construction,”2012 (ASTM D448-12).
ASTM D522 is the American Society of Testing and Materials document titled, “Standard Test Methods for
Mandrel Bend Test of Attached Organic Coatings,” 2013 (ASTM D522/D522M-13).
ASTM D822 is the American Society of Testing and Materials document titled, “Standard Practice for Filtered
Open-Flame Carbon-Arc Exposures of Paint and Related Coatings,” 2013 (ASTM D822/D822M-13).
ASTM D1003 is the American Society for Testing and Materials document titled “Standard Test Method for Haze
and Luminous Transmittance of Transparent Plastics,” 2013 (ANSI/ASTM D1003-13).
ASTM D1653 is the American Society of Testing and Materials document titled, “Standard Test Methods for Water
Vapor Transmission of Organic Coating Films,” 2013 (ASTM D1653-13).
ASTM D1863 is the American Society for Testing and Materials document titled, “Standard Specification for
Mineral Aggregate Used on Built-Up Roofs,”2011 (ASTM D1863/D1863M-05 (2011)).
ASTM D2370 is the American Society of Testing and Materials document titled, “Standard Test Method for Tensile
Properties of Organic Coatings,” 2010 ASTM D2370-98 (2010).
ASTM D2824 is the American Society of Testing and Materials document titled “Standard Specification for
Aluminum-Pigmented Asphalt Roof Coatings, Nonfibered, Asbestos Fibered, and Fibered without Asbestos,” 2013
ASTM D3468 is the American Society of Testing and Materials document titled, “Standard Specification for Liquid-
Applied Neoprene and Chlorosulfonated Polyethylene Used in Roofing and Waterproofing,” 2013 (ASTM
ASTM D3805 is the American Society of Testing and Materials document titled “Standard Guide for Application of
Aluminum-Pigmented Asphalt Roof Coatings,” 1997 (ASTM D3805/D3805M-97 (2009)).
ASTM D4798 is the American Society for Testing and Materials document titled “Standard Test Method for
Accelerated Weathering Test Conditions and Procedures for Bituminous Materials (Xenon-Arc Method),” 2011
ASTM D5870 is the American Society of Testing and Materials document titled, “Standard Practice for Calculating
Property Retention Index of Plastics,” 2011 (ASTM D5870-11).
ASTM D6083 is the American Society of Testing and Materials document titled, “Standard Specification for Liquid
Applied Acrylic Coating Used in Roofing,” 2005 (ASTM D6083-05e1).
ASTM D6694 is the American Society of Testing and Materials document titled, “Standard Specification for Liquid-
Applied Silicone Coating Used in Spray Polyurethane Foam Roofing,” 2013 (ASTM D6694/D6694M-08 (2013).
ASTM D6848 is the American Society of Testing and Materials document titled “Standard Specification for
Aluminum-Pigmented Emulsified Asphalt Used as a Protective Coating for Roofing,” 2002 (ASTM D6848-02).
ASTM E96 is the American Society for Testing and Materials document titled “Standard Test Methods for Water
Vapor Transmission of Materials,” 2014 (ASTM E96/E96M-14).
ASTM E283 is the American Society for Testing and Materials document titled “Standard Test Method for
Determining the Rate of Air Leakage Through Exterior Windows, Curtain Walls, and Doors Under Specified
Pressure Differences Across the Specimen,” 2012 (ASTM E283-04(2012)).
ASTM E408 is the American Society for Testing and Materials document titled, “Standard Test Methods for Total
Normal Emittance of Surfaces Using Inspection-Meter Techniques,” 2013 (ASTM E408-13).
ASTM E779 is the American Society for Testing and Materials document titled, “Standard Test Method for
Determining Air Leakage Rate by Fan Pressurization,” 2010 (ASTM E779-10).
ASTM E972 is the American Society for Testing and Materials document titled, “Standard Test Method for Solar
Photometric Transmittance of Sheet Materials Using Sunlight,”1996 (ASTM E972-96(2013)).
ASTM E1677 is the American Society for Testing and Materials document titled, “Standard Specification for an Air
Retarder (AR) Material or System for Low-Rise Framed Building Walls,” 2011 (ASTM E1677-11).
ASTM E1918 is the American Society for Testing and Materials document entitled, “Standard Test Method for
Measuring Solar reflectance of Horizontal and Low-Sloped Surfaces in the Field,”2015 (ASTM E1918-06(2015) ).
ASTM E1980 is the American Society for Testing and Materials document titled, “Standard Practice for Calculating
Solar Reflectance Index of Horizontal and Low-Sloped Opaque Surface,” 2011 (ASTM E1980-11)
ASTM E2178 is the American Society for Testing and Materials document titled, “Standard Test Method for Air
Permeance of Building Materials,” 2013 (ASTM E21778-13).
determining air leakage of air barrier assemblies” 2011 (ASTM E2357-11).
ATTIC is an enclosed space directly below the roof deck and above the ceiling beams.
AUTOMATIC is capable of operating without human intervention.
AUTOMATED TELLER MACHINE (ATM) is any electronic information processing device which accepts or
dispenses currency in connection with a credit, deposit, or convenience account without involvement by a clerk.
BACK-UP COMPRESSORS are those compressors not used to meet peak compressed air loads. Back-up
compressors are physically connected to the compressed air piping system and can be automatically controlled to
turn on if one of the online compressors fails. Back-up compressors do not normally operate.
BELOW-GRADE WALL is the portion of a wall, enclosing conditioned space that is below the grade line.
BUBBLE POINT is the liquid saturation temperature of a refrigerant at a specified pressure.
BUILDING is any structure or space covered by Section 100.0 of the Building Energy Efficiency Standards.
BUILDING COMMISSIONING is a systematic quality assurance process that spans the entire design and
construction process, including verifying and documenting that building systems and components are planned,
designed, installed, tested, operated and maintained to meet the owner’s project requirements.
BUILDING ENVELOPE is the ensemble of exterior and demising partitions of a building that enclose conditioned
CALL CENTER is a phone center that handles large number of phone calls including but not limited to help desk,
customer and sales support, technical support, emergency response, telephone answering service, and inbound and
CENTRAL FAN-INTEGRATED VENTILATION SYSTEM is a central forced air heating and/or cooling system
which is intended to operate on a regular basis to bring in outdoor ventilation air and/or distribute air around the
home for comfort and ventilation even when heating and cooling are not needed.
CERTIFIED TO THE ENERGY COMMISSION means, when used in association with appliances, certified
under Section 1606 of Title 20 of the California Code of Regulations; and otherwise means certified by the
manufacturer in a declaration, executed under penalty of perjury under the laws of the State of California, that all the
information provided pursuant to the certification is true, complete, accurate and in compliance with all applicable
provisions of Part 6; and if applicable that the equipment, product, or device was tested under the applicable test
method specified in Part 6.
CERTIFYING ORGANIZATION is an independent organization recognized by the Commission to certify
manufactured devices for performance values in accordance with procedures adopted by the Commission.
CIE 13.3 is the International Commission on Illumination (Commission Internationale de l’Eclairage) document
titled “Method of Measuring and Specifying Colour Rendering Properties of Light Sources,” 1995 (CIE 13.3-1995).
CIE 15 is the International Commission on Illumination (Commission Internationale de l’Eclairage) document titled
“Technical Report: Colorimetry,” 2004 (CIE 15:2004).
CLIMATE ZONES are the 16 geographic areas of California for which the Commission has established typical
weather data, prescriptive packages and energy budgets. Climate zones are defined by ZIP code and listed in
Reference Joint Appendix JA2 FIGURE 100.1-A is an approximate map of the 16 Climate Zones.
CLOSED-CIRCUIT COOLING TOWER is a cooling tower that utilizes indirect contact between a heated fluid,
typically water or glycol, and the cooling atmosphere to transfer the source heat load through sensible heat, latent
heat, and mass transfer indirectly to the air, essentially combining a heat exchanger and cooling tower into an
integrated and relatively compact device.
CODES, CALIFORNIA HISTORICAL BUILDING CODE is the California Historical Building Code,
California Code of Regulations, Title 24, Part 8 and Part 2 (Chapter 34).
CODES, CBC is the 2013 California Building Code.
CODES, CEC is the 2013 California Electric Code.
CODES, CMC is the 2013 California Mechanical Code.
CODES, CPC is the 2013 California Plumbing Code.
COEFFICIENT OF PERFORMANCE (COP), COOLING, is the ratio of the rate of net heat removal to the rate
of total energy input, calculated under designated operating conditions and expressed in consistent units, as
determined using the applicable test method in the Appliance Efficiency Regulations or Section 110.2.
COEFFICIENT OF PERFORMANCE (COP), HEATING, is the ratio of the rate of net heat output to the rate of
total energy input, calculated under designated operating conditions and expressed in consistent units, as determined
using the applicable test method in the Appliance Efficiency Regulations or Section 110.2.
COEFFICIENT OF PERFORMANCE (COP), HEAT PUMP is the ratio of the rate of useful heat output
delivered by the complete heat pump unit (exclusive of supplementary heating) to the corresponding rate of energy
input, in consistent units and as determined using the applicable test method in Appliance Efficiency Regulations or
COMBUSTION AIR POSITIVE SHUT-OFF is a means of restricting air flow through a boiler combustion
chamber during standby periods, used to reduce standby heat loss. A flue damper and a vent damper are two
examples of combustion air positive shut-off devices.
COMBUSTION EFFICIENCY is a measure of the percentage of heat from the combustion of gas or oil that is
transferred to the medium being heated or lost as jacket loss.
COMMERCIAL BOILER is a type of boiler with a capacity (rated maximum input) of 300,000 Btus per hour
(Btu/h) or more and serving a space heating or water heating load in a commercial building.
COMMISSION is the California State Energy Resources Conservation and Development Commission.
COMPLEX MECHANICAL SYSTEMS: are systems that include 1) fan systems each serving multiple
thermostatically controlled zones; or 2) built-up air handler systems (non-unitary or non-packaged HVAC
equipment); or 3) hydronic or steam heating systems; or 4) hydronic cooling systems. Complex systems are NOT
the following: (a) unitary or packaged equipment listed in Tables 110.2-A, 110.2-B, 110.2-C, and 110.2-E that each
serve one zone, or (b) two-pipe, heating only systems serving one or more zones.
COMPLIANCE SOFTWARE is software that has been approved pursuant to Section 10-109 of Part 1 of Title 24
of the California Code of Regulations, to demonstrate compliance with the performance approach of Part 6.
COMPRESSED AIR SYSTEM is a system of at least one compressor providing compressed air at 40 psig or
COMPUTER ROOM is a room within a building whose primary function is to house electronic equipment and that
has a design equipment power density exceeding 20 watts/ft2 (215 watts/m2) of conditioned floor area.
CONDENSER SPECIFIC EFFICIENCY is the full load condenser Total Heat of Rejection (THR) capacity at
standardized conditions divided by the fan input electric power (including but not limited to spray pump electric
input power for evaporative condensers) at 100 percent rated fan speed.
CONDITIONED FLOOR AREA (CFA) is the floor area (in square feet) of enclosed conditioned space on all
floors of a building, as measured at the floor level of the exterior surfaces of exterior walls enclosing the conditioned
CONDITIONED SPACE is space in a building that is either directly conditioned or indirectly conditioned.
CONDITIONED SPACE, DIRECTLY is an enclosed space that is provided with wood heating, is provided with
mechanical heating that has a capacity exceeding 10 Btu/hr-ft², or is provided with mechanical cooling that has a
capacity exceeding 5 Btu/hr-ft², unless the space-conditioning system is designed for process space or process load.
(See “process load” and “process space.”)
CONDITIONED SPACE, INDIRECTLY is enclosed space, including, but not limited to, unconditioned volume
in atria, that (1) is not directly conditioned space; and (2) either (a) has a thermal transmittance area product (UA) to
directly conditioned space exceeding that to the outdoors or to unconditioned space and does not have fixed vents or
openings to the outdoors or to unconditioned space, or (b) is a space through which air from directly conditioned
spaces is transferred at a rate exceeding three air changes per hour.
CONDITIONED VOLUME is the total volume (in cubic feet) of the conditioned space within a building.
CONTINUOUS INSULATION (c.i.) is insulation that is continuous across all assemblies that separate conditioned
from unconditioned space. It is installed on the exterior or interior or is integral to any opaque surface of the building
envelope and has no thermal bridges other than fasteners and necessary service openings.
CONTROLLED ATMOSPHERE is an airtight space maintained at reduced oxygen levels for the purpose of
reducing respiration of perishable product in long term storage.
COOLER is a space to be capable of operation at a temperature greater than or equal to 28°F but less than 55°F.
COOL ROOF is a roofing material with high thermal emittance and high solar reflectance, or low thermal emittance
and exceptionally high solar reflectance as specified in Part 6 that reduces heat gain through the roof.
COOLING EQUIPMENT is equipment used to provide mechanical cooling for a room or rooms in a building.
CRAWL SPACE is a space immediately under the first floor of a building adjacent to grade.
CRRC-1 is the Cool Roof Rating Council document titled “Product Rating Program Manual.”
CTI is the Cooling Technology Institute.
CTI ATC-105 is the Cooling Technology Institute document titled “Acceptance Test Code for Water Cooling
Towers,” 2000 (CTI ATC-105-00).
CTI ATC-105S(11) is the Cooling Technology Institute document titled “Acceptance Test Code for Closed-Circuit
Cooling Towers,” 2011 (CTI ATC-105-11).
CTI STD-201 is the Cooling Technology Institute document titled “Standard for Thermal Performance Certification
of Evaporative Heat Rejection Equipment,” 2011 (CTI STD-201-11).
CURRENT AIR DEMAND is the actual cubic feet per minute (acfm) of total air flow necessary for end uses in a
compressed air system.
C-VALUE (also known as C-factor) is the time rate of heat flow through unit area of a body induced by a unit
temperature difference between the body surfaces, in Btu (hr x ft² x °F). It is not the same as K-value or K-factor.
CYCLES OF CONCENTRATION is the number of times the concentration of total dissolved solids (TDS) in
cooling tower water is multiplied relative to the TDS in the makeup water. Because evaporation of pure water leaves
dissolved solids behind in the system water, TDS increases over time as the tower operates. The number of times the
dissolved minerals are concentrated is relative to the TDS in the makeup water. For example, five cycles of
concentration represents five times the concentration of solids in the cooling tower system water relative to the TDS
in the makeup water entering the tower.
DATA CENTER is a building whose primary function is to house computer room(s).
DAYLIT ZONE is the floor area under skylights or next to windows. Types of Daylit Zones include Primary Sidelit
Daylit Zone, Secondary Sidelit Daylit Zone, and Skylit Daylit Zone.
DEADBAND is the temperature range within which the HVAC system is neither calling for heating or cooling.
DECORATIVE GAS APPLIANCE is a gas appliance that is designed or installed for visual effect only, cannot
burn solid wood, and simulates a fire in a fireplace.
DEGREE DAY, HEATING, is a unit, based upon temperature difference and time, used in estimating fuel
consumption and specifying nominal annual heating load of a building. For any one day, when the mean temperature
is less than 65°F, there exist as many degree days as there are Fahrenheit degrees difference in temperature between
the mean temperature for the day and 65°F. The number of degree days for specific geographical locations are those
listed in the Reference Joint Appendix JA2. For those localities not listed in the Reference Joint Appendix JA2, the
number of degree days is as determined by the applicable enforcing agency.
DEMAND RESPONSE is short-term changes in electricity usage by end-use customers from their normal
consumption patterns. Demand response may be in response to:
a. changes in the price of electricity; or
b. participation in programs or services designed to modify electricity use
i. in response to wholesale market prices, or
ii. when system reliability is jeopardized.
DEMAND RESPONSE PERIOD is a period of time during which electricity loads are modified in response to a
demand response signal.
DEMAND RESPONSE SIGNAL is a signal sent by the local utility, Independent System Operator (ISO), or
designated curtailment service provider or aggregator, to a customer, indicating a price or a request to modify
electricity consumption, for a limited time period.
DEMAND RESPONSIVE CONTROL is a kind of control that is capable of receiving and automatically
responding to a demand response signal.
DEMISING PARTITION is a wall, fenestration, floor, or ceiling that separates conditioned space from enclosed
DESIGN CONDITIONS are the parameters and conditions used to determine the performance requirements of
space-conditioning systems. Design conditions for determining design heating and cooling loads are specified in
Section 140.4(b) for nonresidential, high-rise residential, and hotel/motel buildings and in Section 150.0(h) for lowrise
DESIGN HEAT GAIN RATE is the total calculated heat gain through the building envelope under design
DESIGN HEAT LOSS RATE is the total calculated heat loss through the building envelope under design
DESIGN REVIEW is an additional review of the construction documents (drawings and specifications) that seeks
to improve compliance with existing Title 24 regulations, to encourage adoption of best practices in design, and to
encourage designs that are constructible and maintainable. It is an opportunity for an experienced design engineer or
architect to look at a project with a fresh perspective in an effort to catch missing or unclear design information and
to suggest design enhancements.
DEW POINT TEMPERATURE is the vapor saturation temperature at a specified pressure for a substance
undergoing phase change from vapor to liquid.
DIRECT DIGITAL CONTROL (DDC) is a type of control where controlled and monitored analog or binary data,
such as temperature and contact closures, are converted to digital format for manipulation and calculations by a
digital computer or microprocessor, then converted back to analog or binary form to control mechanical devices.
DIRECT-VENT APPLIANCE or “sealed combustion” appliance is an appliance that is constructed and installed so
that air from combustion is derived directly from the outdoors and flue gases are discharged to the outdoors.
DISPLAY PERIMETER is the length of an exterior wall in a Group B; Group F, Division 1; or Group M,
Occupancy that immediately abuts a public sidewalk, measured at the sidewalk level for each story that abuts a
DOOR is an operable opening in the building envelope, including swinging and roll-up doors, fire doors, pet doors
and access hatches with less than 50 percent glazed area. When that operable opening has 50 percent or more glazed
area it is a glazed door. See Fenestration: Glazed Door.
DUAL-GLAZED GREENHOUSE WINDOWS are a type of dual-glazed fenestration product which adds
conditioned volume but not conditioned floor area to a building.
DUCT SEALING is a procedure for installing a space conditioning distribution system that minimizes leakage of
air from or to the distribution system. Minimum specifications for installation procedures, materials, diagnostic
testing and field verification are contained in the Reference Residential Appendix RA3 and Reference Nonresidential
DUCT SYSTEM is all the ducts, duct fittings, plenums and fans when assembled to form a continuous passageway
for the distribution of air.
DUCTED SYSTEM is an air conditioner or heat pump, either a split system or single-packaged unit, that is
designed to be permanently installed equipment and delivers conditioned air to an indoor space through a duct.
DWELLING is a building that contains one or two dwelling units used, intended or designed to be used, rented,
leased, let or hired out to be occupied for living purposes.
DWELLING UNIT is a single unit providing complete, independent living facilities for one or more persons
including access permanent provisions for living, sleeping, eating, cooking and sanitation.
EAST-FACING (See “orientation.”)
ECONOMIZER, AIR, is a ducting arrangement, including dampers, linkages, and an automatic control system that
allows a cooling supply fan system to supply outside air to reduce or eliminate the need for mechanical cooling.
ECONOMIZER, WATER, is a system by which the supply air of a cooling system is cooled directly or indirectly
by evaporation of water, or other appropriate fluid, in order to reduce or eliminate the need for mechanical cooling.
ELECTRICAL POWER DISTRIBUTION SYSTEMS. The following definitions are intended to apply to Section
EQUIPMENT. A general term, including devices, luminaires, apparatus, machinery, and the like used as a part
of, or in connection with, an electrical installation.
PLUG LOAD is the energy consumed by any appliances or electronic device that is plugged into a receptacle or
receptacle outlet. Plug loads are not related to general lighting, heating, ventilation, cooling, and water heating,
domestic and service water system, renewable power, information technology equipment, computer room
electronic equipment, and electric vehicle charging.
ELECTRICAL METERING is a device or system for measuring the electrical power and energy supplied to a
customer or premise(s).
LOW VOLTAGE DRY-TYPE DISTRIBUTION TRANSFORMER is a distribution transformer that
has an input voltage of 600 volts or less, that is air-cooled, and that does not use oil as a coolant.
SERVICE is the conductors and equipment for delivering electric energy from the serving utility to the wiring
system of the premise served.
SERVICE EQUIPMENT is the necessary equipment, usually consisting of a circuit breaker(s) or switch(es)
and fuse(s) and their accessories, connected to the load end of service conductors to a building or other structure,
or an otherwise designated area, and intended to constitute the main control and cutoff of the supply.
ELECTRONICALLY-COMMUTATED MOTOR is a brushless DC motor with a permanent magnet rotor that is
surrounded by stationary motor windings, and an electronic controller that varies rotor speed and direction by
sequentially supplying DC current to the windings.
EMITTANCE, THERMAL is the ratio of the radiant heat flux emitted by a sample to that emitted by a blackbody
radiator at the same temperature.
ENCLOSED SPACE is space that is substantially surrounded by solid surfaces, including walls, ceilings or roofs,
doors, fenestration areas, and floors or ground.
ENERGY BUDGET is the maximum amount of Time Dependent Valuation (TDV) energy that a proposed
building, or portion of a building, can be designed to consume, calculated with the approved procedures specified in
ENERGY COMMISSION is the California State Energy Resources Conservation and Development Commission.
ENERGY EFFICIENCY RATIO (EER) is the ratio of net cooling capacity (in Btu/hr) to total rate of electrical
energy input (in watts), of a cooling system under designated operating conditions, as determined using the
applicable test method in the Appliance Efficiency Regulations or Section 110.2.
ENERGY FACTOR (EF) of a water heater is a measure of overall water heater efficiency, as determined using the
applicable test method in the Appliance Efficiency Regulations.
ENERGY MANAGEMENT CONTROL SYSTEM (EMCS) is a computerized control system designed to
regulate the energy consumption of a building by controlling the operation of energy consuming systems, such as the
heating, ventilation and air conditioning (HVAC), lighting, and water heating systems, and is capable of monitoring
environmental and system loads, and adjusting HVAC operations in order to optimize energy usage and respond to
demand response signals.
ENERGY OBTAINED FROM DEPLETABLE SOURCES is electricity purchased from a public utility, or any
energy obtained from coal, oil, natural gas, or liquefied petroleum gases.
ENERGY OBTAINED FROM NONDEPLETABLE SOURCES is energy that is not energy obtained from
ENFORCEMENT AGENCY is the city, county, or state agency responsible for issuing a building permit.
ENTIRE BUILDING is the ensemble of all enclosed space in a building, including the space for which a permit is
sought, plus all existing conditioned and unconditioned space within the structure.
ENVELOPE (See “building envelope”)
EXFILTRATION is uncontrolled outward air leakage from inside a building, including leakage through cracks and
interstices, around windows and doors, and through any other exterior partition or duct penetration.
EXTERIOR FLOOR/SOFFIT is a horizontal exterior partition, or a horizontal demising partition, under
conditioned space. For low-rise residential occupancies, exterior floors also include those on grade.
EXTERIOR PARTITION is an opaque, translucent, or transparent solid barrier that separates conditioned space
from ambient air or space. For low-rise residential occupancies, exterior partitions also include barriers that separate
conditioned space from unconditioned space, or the ground.
EXTERIOR ROOF/CEILING is an exterior partition, or a demising partition, that has a slope less than 60 degrees
from horizontal, that has conditioned space below, and that is not an exterior door or skylight.
EXTERIOR ROOF/CEILING AREA is the area of the exterior surface of exterior roof/ceilings.
EXTERIOR WALL is any wall or element of a wall, or any member or group of members, which defines the
exterior boundaries or courts of a building and which has a slope of 60 degrees or greater with the horizontal plane.
An exterior wall or partition is not an exterior floor/soffit, exterior door, exterior roof/ceiling, window, skylight, or
EXTERIOR WALL AREA is the area of the opaque exterior surface of exterior walls.
FACADE is the contiguous exterior of a building surface, but not limited to fenestration products.
FACTORY ASSEMBLED COOLING TOWERS are cooling towers constructed from factory-assembled modules
either shipped to the site in one piece or put together in the field.
FENESTRATION: Includes the following:
ACE is an NFRC-Approved Calculation Entity that conducts calculations of fenestration product ratings for
certification authorization using the NFRC Component Modeling approach and issues label certificates to
Specifying Authorities for product certification authorization in accordance with NFRC requirements.
ALTERATION is any change to an existing building’s exterior fenestration product that is not a repair (see
Fenestration Repair) that:
i. Replaces existing fenestration in an existing wall or roof with no net area added; or
ii. Replaces existing fenestration and adds new net area in the existing wall or roof; or
iii. Adds a new window that increases the net fenestration area to an existing wall or roof.
ALTERED COMPONENT is a new fenestration component that has undergone an alteration other than a
repair and is subject to all applicable Standards requirements.
BAY WINDOW is a combination assembly which is composed of three or more individual windows either
joined side by side or installed within opaque assemblies and which projects away from the wall on which it is
installed. Center windows, if used are parallel to the wall on which the bay is installed, the end panels or two
side windows are angled with respect to the center window. Common angles are 30° and 45°, although other
angles may be employed.
CMA (component modeling approach) is a fenestration product certification program from the National
Fenestration Rating Council (NFRC) that enables energy-related performance ratings for nonresidential
fenestration products, including the thermal performance U-factor, Solar Heat Gain Coefficient, and Visible
CMAST (Component Modeling Approach Software Tool) is an NFRC approved software which allows a user
to create a fenestration product “virtually,” and generate its energy-related performance ratings, including the
thermal performance U-factor, Solar Heat Gain Coefficient, and Visible Transmittance.
CURTAIN WALL/STOREFRONT is an external nonbearing wall intended to separate the exterior
nonconditioned and interior conditioned spaces. It also consists of any combination of framing materials, fixed
glazing, opaque glazing, operable windows, or other in-fill materials.
GLAZED DOOR is an exterior door having a glazed area of 50 percent or greater of the area of the door.
DUAL-GLAZED GREENHOUSE WINDOWS is a double glass pane separated by an air or other gas space
which adds conditioned volume but not conditioned floor area to a building.
DYNAMIC GLAZING SYSTEMS are glazing systems that have the ability to reversibly change their
performance properties, including U-factor, Solar Heat Gain Coefficient (SHGC), and/or Visible Transmittance
(VT) between well-defined end points. These may include, but are not limited to chromogenic glazing systems
and integrated shading systems (defined below). Dynamic Glazing systems do not include internally mounted or
externally mounted shading devices that attach to the window framing/glazing that may or may not be
CHROMOGENIC GLAZING is a class of switchable glazing which includes active materials (e.g.
electrochromic) and passive materials (e.g. photochromic and thermochromic) permanently integrated into
the glazing assembly. Their primary function is to switch reversibly from a high transmission state to a low
transmission state with associated changes in VT and SHGC.
INTEGRATED SHADING SYSTEM is a class of fenestration products including an active layer: e.g.
shades, louvers, blinds or other materials permanently integrated between two or more glazing layers. The
U-factor and/or SHGC and VT of the insulating glass assembly can be altered by reversibly changing the
enclosed active layer.
FENESTRATION AREA for windows is the total window rough opening area which includes the fenestration,
fenestration frame components in the exterior walls and roofs.
FENESTRATION PRODUCT is any transparent or translucent material plus any sash, frame, mullions and
dividers, in the facade of a building, including, but not limited to, windows, sliding glass doors, french doors,
skylights, curtain walls, dynamic glazing, garden windows and glass block.
FENESTRATION REPAIR is the reconstruction or renewal for the purpose of maintenance of any
fenestration product, component or system and shall not increase the preexisting energy consumption of the
repaired fenestration product, component, system, or equipment. Replacement of any component, system, or
equipment for which there are requirements in the Standards are considered an alteration (see Fenestration,
Alterations) and not a repair and is subject to the requirements of Part 6 of the Standards.
FIELD-FABRICATED is a fenestration product whose frame is made at the construction site of standard
dimensional lumber or other materials that were not previously cut, or otherwise formed with the specific
intention of being used to fabricate a fenestration product. Field fabricated does not include site-built
FIN is an opaque surface, oriented vertically and projecting outward horizontally from an exterior vertical
FIN OFFSET is the horizontal distance from the edge of exposed exterior glazing at the jamb of a window to
FIN PROJECTION is the horizontal distance, measured outward horizontally, from the surface of exposed
exterior glazing at the jamb of a window to the outward edge of a fin.
FIXED is fenestration that is not designed to be opened or closed.
GREENHOUSE or GARDEN WINDOW is a window unit that consists of a three-dimensional, five-sided
structure generally protruding from the wall in which it is installed. Operating sash may or may not be included.
MANUFACTURED or KNOCKED DOWN PRODUCT is a fenestration product constructed of materials
which are factory cut or otherwise factory formed with the specific intention of being used to fabricate a
fenestration product. Knocked down or partially assembled products may be sold as a fenestration product when
provided with temporary and permanent labels as described in Section 10-111; or as a site-built fenestration
product when not provided with temporary and permanent labels as described in Section 10-111.
NFRC 100 is the National Fenestration Rating Council document titled “NFRC 100: Procedure for Determining
Fenestration Product U-factors.”
NFRC 200 is the National Fenestration Rating Council document titled “NFRC 200: Procedure for Determining
Fenestration Product Solar Heat Gain Coefficients and Visible Transmittance at Normal Incidence.” (2014).
NFRC 202 is the National Fenestration Rating Council document titled “NFRC 202: Procedures for
Determining Translucent Fenestration Product Visible Transmittance at Normal Incidence.” (2014).
NFRC 203 is the National Fenestration Rating Council document titled “NFRC 203: Procedure for Determining
Visible Transmittance of Tubular Daylighting Devices.” (2014).
NFRC 400 is the National Fenestration Rating Council document titled “NFRC 400: Procedure for Determining
Fenestration Product Air Leakage.” (2014).
OPERABLE SHADING DEVICE is a device at the interior or exterior of a building or integral with a
fenestration product, which is capable of being operated, either manually or automatically, to adjust the amount
of solar radiation admitted to the interior of the building.
RELATIVE SOLAR HEAT GAIN COEFFICIENT (RSHGC) is the ratio of solar heat gain through a
fenestration product (corrected for external shading) to the incident solar radiation. Solar heat gain includes
directly transmitted solar heat and absorbed solar radiation, which is then reradiated, conducted, or convected
into the space.
SITE-BUILT is fenestration designed to be field-glazed or field assembled units using specific factory cut or
otherwise factory formed framing and glazing units, that are manufactured with the intention of being assembled
at the construction site. These include storefront systems, curtain walls, and atrium roof systems.
SOLAR HEAT GAIN COEFFICIENT (SHGC) is the ratio of the solar heat gain entering the space through
the fenestration area to the incident solar radiation. Solar heat gain includes directly transmitted solar heat and
absorbed solar radiation, which is then reradiated, conducted, or convected into the space.
SPANDREL is opaque glazing material most often used to conceal building elements between floors of a
building so they cannot be seen from the exterior, also known as “opaque in-fill systems”.
TINTED GLASS is colored glass by incorporation of a mineral admixture resulting in a degree of tinting. Any
tinting reduces both visible and radiant transmittance.
VISIBLE TRANSMITTANCE (VT) is the ratio (expressed as a decimal) of visible light that is transmitted
through a glazing fenestration. The higher the VT rating, the more light is allowed through a window.
WINDOW is fenestration that is not a skylight and that is an assembled unit consisting of a frame and sash
component holding one or more pieces of glazing.
WINDOW AREA is the area of the surface of a window, plus the area of the frame, sash, and mullions.
WINDOW HEAD HEIGHT is the height from the floor to the top of the window.
WINDOW WALL RATIO is the ratio of the window area to the gross exterior wall area.
FIELD ERECTED COOLING TOWERS are cooling towers which are custom designed for a specific application
and which cannot be delivered to a project site in the form of factory assembled modules due to their size,
configuration, or materials of construction.
FIREPLACE is a hearth and fire chamber, or similar prepared place, in which a fire may be made and which is built
in conjunction with a flue or chimney, including but not limited to factory-built fireplaces, masonry fireplaces, and
masonry heaters as further clarified in the CBC.
FLOOR/SOFFIT TYPE is a type of floor/soffit assembly having a specific heat capacity, framing type, and Ufactor.
FLUID COOLER is a fan-powered heat rejection device that includes a water or glycol circuit connected by a
closed circulation loop to a liquid-cooled refrigerant condenser, and may be either evaporative-cooled, air-cooled, or
a combination of the two.
FLUX is the rate of energy flow per unit area.
FOOD PREPARATION EQUIPMENT is cooking equipment intended for commercial use, including coffee
machines, espresso coffee makers, conductive cookers, food warmers including heated food servers, fryers, griddles,
nut warmers, ovens, popcorn makers, steam kettles, ranges, and cooking appliances for use in commercial kitchens,
restaurants, or other business establishments where food is dispensed.
FREEZER is a space designed to be capable of operation at less than 28°F.
GAS COOLING EQUIPMENT is cooling equipment that produces chilled water or cold air using natural gas or
liquefied petroleum gas as the primary energy source.
GAS HEATING SYSTEM is a system that uses natural gas or liquefied petroleum gas as a fuel to heat a
GAS LOG is a self-contained, free-standing, open-flame, gas-burning appliance consisting of a metal frame or base
supporting simulated logs, and designed for installation only in a vented fireplace.
GLAZING (See “fenestration product”)
GLOBAL WARMING POTENTIAL (GWP) is the radiative forcing impact of one mass-based unit of a given
greenhouse gas relative to an equivalent unit of carbon dioxide over a given period of time.
GLOBAL WARMING POTENTIAL VALUE (GWP Value) is the 100-year GWP value published by the
Intergovernmental Panel on Climate Change (IPCC) in either its Second Assessment Report (SAR) (IPCC, 1995), or
its Fourth Assessment A-3 Report (AR4) (IPCC, 2007). Both the 1995 IPCC SAR values and the 2007 IPCC AR4
values are published in table 2.14 of the 2007 IPCC AR4. The SAR GWP values are found in column “SAR (100-
yr)” of Table 2.14.; the AR4 GWP values are found in column “100 yr” of Table 2.14.”
GOVERNMENTAL AGENCY is any public agency or subdivision thereof, including, but not limited to, any
agency of the state, a county, a city, a district, an association of governments, or a joint power agency.
GROSS EXTERIOR ROOF AREA is the sum of the skylight area and the exterior roof/ceiling area.
GROSS EXTERIOR WALL AREA is the sum of the window area, door area, and exterior wall area.
HABITABLE SPACE is space in a building for living, sleeping, eating or cooking. Bathrooms, toilets, hallways,
storage areas, closets, or utility rooms and similar areas are not considered habitable spaces.
HABITABLE STORY is a story that contains space in which humans may work or live in reasonable comfort, and
that has at least 50 percent of its volume above grade.
HEAT CAPACITY (HC) or thermal capacity, is the measurable physical quantity that characterizes the amount of
heat required to change a substance’s temperature by a given amount..
HEAT PUMP is an appliance, that consists of one or more assemblies; that uses an indoor conditioning coil, a
compressor, and a refrigerant-to-outdoor air heat exchanger to provide air heating; and that may also provide air
cooling, dehumidifying, humidifying, circulating, or air cleaning.
HEATED SLAB FLOOR is a concrete floor either, on-grade, raised, or a lightweight concrete slab topping.
Heating is provided by a system placed within or under the slab, and is sometimes referred to as a radiant slab floor.
HEATING EQUIPMENT is equipment used to provide mechanical heating for a room or rooms in a building.
HEATING SEASONAL PERFORMANCE FACTOR (HSPF) is the total heating output of a central airconditioning
heat pump (in Btu) during its normal use period for heating divided by the total electrical energy input
(in watt-hours) during the same period, as determined using the applicable test method in the Appliance Efficiency
HI is the Hydronics Institute of the Gas Appliance Manufacturers Association (GAMA).
HI HTG BOILER STANDARD is the Hydronics Institute document titled “Testing and Rating Standard for Rating
HIGH-RISE RESIDENTIAL BUILDING is a building, other than a hotel/motel, of Occupancy Group R-2 or R-4
with four or more habitable stories.
HOTEL/MOTEL is a building or buildings that has six or more guest rooms or a lobby serving six or more guest
rooms, where the guest rooms are intended or designed to be used, or which are used, rented, or hired out to be
occupied, or which are occupied for sleeping purposes by guests, and all conditioned spaces within the same building
envelope. Hotel/motel also includes all conditioned spaces which are (1) on the same property as the hotel/motel, (2)
served by the same central heating, ventilation, and air-conditioning system as the hotel/motel, and (3) integrally
related to the functioning of the hotel/motel as such, including, but not limited to, exhibition facilities, meeting and
conference facilities, food service facilities, lobbies, and laundries.
HVAC SYSTEM is a space-conditioning system or a ventilation system.
IES HB (See IES Lighting Handbook)
IES LIGHTING HANDBOOK is the Illuminating Engineering Society document titled “The IES Lighting
Handbook: Reference and Applications, Tenth Edition” (2011).
IES LM-79-08 is the Illuminating Engineering Society document titled, “IES Approved Method for the Electrical
and Photometric Measurements of Solid-State Lighting Products.’
IES TM-15-11 is the Illuminating Engineering Society document titled, “Luminaire” Classification Systems for
INFILTRATION is uncontrolled inward air leakage from outside a building or unconditioned space, including
leakage through cracks and interstices, around windows and doors, and through any other exterior or demising
partition or pipe or duct penetration. See AIR BARRIER.
INTEGRATED ENERGY EFFICIENCY RATIO (IEER) is a single-number cooling part load efficiency figure
of merit calculated as specified by the method described in ANSI/AHRI Standard 340/360/1230 . This metric
replaces the IPLV for ducted and non-ducted units.
INTEGRATED PART LOAD VALUE (IPLV) is a single-number cooling partload efficiency figure of merit
calculated as specified by the method described in ANSI/AHRI Standard 550/590 for use with chillers.
ISO STANDARD 17025 is the International Organization for Standardization document titled “General Criteria for
the Competence of Testing and Calibration Laboratories”, 2005 (ANS/ISO/IEC Standard 17025:2005).
ISO 13256-1 is the International Organization for Standardization document titled “Water-source heat pumps —
Testing and rating for performance — Part 1: Water-to-air and brine-to-air heat pumps,” 1998.
ISO 13256-2 is the International Organization for Standardization document titled “Water-source heat pumps —
Testing and rating for performance — Part 1: Water-to-water and brine-to-water heat pumps,” 1998.
LANGELIER SATURATION INDEX (LSI) is expressed as the difference between the actual system pH and the
saturation pH. LSI indicates whether water will precipitate, dissolve, or be in equilibrium with calcium carbonate,
and is a function of hardness, alkalinity, conductivity, pH and temperature.
LARGEST NET CAPACITY INCREMENT is the largest increase in capacity when switching between
combinations of base compressors that is expected to occur under the compressed air system control scheme.
ACCENT LIGHTING is directional lighting designed to highlight or spotlight objects. It can be recessed,
surface mounted, or mounted to a pendant, stem, or track.
CHANDELIER is a ceiling-mounted, close-to-ceiling, or suspended decorative luminaire that uses glass,
crystal, ornamental metals, or other decorative material.
COLOR RENDERING INDEX (CRI) is the ability of a light source to reflect the color of illuminated objects
with fidelity relative to ideal or natural light sources of the same color temperature. CRI is calculated according
to CIE 13.3
chromaticity of the radiative emission of heated black body and reported in temperature units of Kelvin
according to CIE 15
COLORED LIGHT SOURCE is a light source designed and marketed as a colored light source and not
designed or marketed for general lighting applications with either of the following characteristics maintained
throughout all modes of operation including color changing operation:
(1) A Color Rendering Index (CRI) less than 40, as determined according to the method set forth in CIE
Publication 13.3; or
(2) A Correlated Color Temperature less than 2,200 K or greater than 7,000 K as determined according to
the method set forth in IES LM-66 or IES LM-79 as appropriate.
COMPACT FLUORESCENT LAMP is a fluorescent lamp less than nine inches maximum overall length
with a T5 or smaller diameter glass tube that is folded, bent, or bridged.
DECORATIVE (LIGHTING/LUMINAIRE) is lighting or luminaires installed only for aesthetic purposes
and that does not serve as display lighting or general lighting.
DISPLAY LIGHTING is lighting that provides a higher level of illuminance to a specific area than the level of
surrounding ambient illuminance. Types of display lighting include:
FLOOR: supplementary lighting required to highlight features, such as merchandise on a clothing rack, which
is not displayed against a wall.
WALL: supplementary lighting required to highlight features, such as merchandise on a shelf, which is
displayed on perimeter walls.
WINDOW: lighting of objects such as merchandise, goods, and artifacts, in a show window, to be viewed from
the outside of a space through a window.
CASE: lighting of small art objects, artifacts, or valuable collections which involves customer inspection of
very fine detail from outside of a glass enclosed display case.
ENCLOSED LUMINAIRES are luminaires which contain enclosed lamp compartments where ventilation
openings are less than 3 square inches per lamp in the lamp compartment as defined by UL 1598.
GENERAL LIGHTING is installed electric lighting that provides a uniform level of illumination throughout
an area, exclusive of any provision for special visual tasks or decorative effect, exclusive of daylighting, and
also known as ambient lighting.
GU-24 is the designation of a lamp holder and socket configuration, based on a coding system by the
International Energy Consortium, where “G” indicates the broad type of two or more projecting contacts, such
as pins or posts, “U” distinguishes between lamp and holder designs of similar type but that are not
interchangeable due to electrical or mechanical requirements, and “24” indicates 24 millimeters center to center
spacing of the electrical contact posts.
ILLUMINANCE is the area density of the luminous flux incident at a point on a surface.
ILLUMINATION is light incident on a surface of body, or the general condition of being illuminated.
INSEPARABLE SOLID STATE LIGHTING (SSL) LUMINAIRE is a luminaire featuring solid state
lighting components such as LEDs and driver components which cannot be easily removed or replaced by the
end user, thus requiring replacement of the entire luminaire. Removal of solid state lighting components may
require the cutting of wires, use of a soldering iron, or damage to or destruction of the luminaire.
INSTITUTIONAL TUNING is the process of adjusting the maximum light output of lighting systems to
support visual needs or save energy. Institutional tuning differs from personal tuning in that the control strategy
is implemented at the institutional rather than the individual user level, and maximum light level adjustments are
available only to authorized personnel.
LAMP is an electrical appliance that produces optical radiation for the purpose of visual illumination, designed
with a base to provide an electrical connection between the lamp and a luminaire, and designed to be installed
into a luminaire by means of a lamp-holder integral to the luminaire
LANDSCAPE LIGHTING is a type of outdoor lighting that is recessed into or mounted on the ground, paving,
or raised deck, which is mounted less than 42 inches above grade or mounted onto trees or trellises, and that is
intended to be aimed only at landscape features.
LANTERN is an outdoor luminaire that uses an electric lamp to replicate the appearance of a pre-electric
lantern, which used a flame to generate light.
LIGHT is the luminous equivalent of power and is properly called luminous flux.
LIGHTING, or illumination, is the application of light to achieve some practical or aesthetic effect.
LIGHT EMITTING DIODE (LED) is a p-n junction solid state diode whose radiated output is a function of
its physical construction, material used and exciting current. The output may be in the near ultraviolet, the
visible or in the infrared regions of the spectrum.
LED LIGHT ENGINE is an integrated assembly comprised of LED packages, LED components, LED arrays,
LED modules, or LED driver, and other optical, thermal, mechanical and electrical components. The device is
intended to connect directly to the branch circuit through a custom connector compatible with the LED
luminaire for which it was designed and does not use an ANSI standard base. (IES RP-16-10).
NON-INTEGRATED LED LAMP is an assembly comprised of an LED array (module) or LED packages
(components) and ANSI standard base. The device is intended to connect to the LED driver of an LED
luminaire through an ANSI standard lamp-holder (socket). The device cannot be connected to the branch circuit
INTEGRATED LED LAMP is an integrated assembly comprised of LED packages (components) or LED
arrays (modules), LED driver, ANSI standard base and other optical, thermal, mechanical and electrical
components. The device is intended to connect directly to the branch circuit via a corresponding ANSI standard
lamp-holder (socket) (ANSI/IES RP-16-10).
LOW VOLTAGE is less than 90 volts.
LUMEN MAINTENANCE is a strategy used to provide a precise, constant level of lighting from a lighting
system regardless of the age of the lamps or the maintenance of the luminaires.
LUMINAIRE is a complete lighting unit consisting of a light source such as a lamp or lamps, together with the
parts that distribute the light, position and protect the light source and connect it to the power supply.
LUMINANCE is the luminous intensity of the source or surface divided by the area of the source or surface
seen by the observer.
LUMINOUS EFFICACY is a measure of the luminous efficiency of a light source. It is the quotient of the total
luminous flux emitted by the total light source power input, expressed in lm/W.
LUMINOUS FLUX is visually evaluated radiant flux and defines “light” for purposes of lighting design and
MARQUEE LIGHTING is a permanent lighting system consisting of one or more rows of many small lamps,
including light emitting diodes (LEDs) lamps, tungsten lamps, low pressure discharge lamps or fiber optic
lighting, attached to a canopy.
ORNAMENTAL LIGHTING for compliance with Part 6 is the following:
LUMINAIRES installed outdoor which are rated for 100 watts or less that are post-top luminaires, lanterns,
pendant luminaires, chandeliers, and marquee lighting, not providing general lighting or task lighting.
DECORATIVE LUMINAIRES installed indoor that are chandeliers, sconces, lanterns, neon and cold
cathode, light emitting diodes, theatrical projectors, moving lights, and light color panels, not providing general
lighting or task lighting.
PENDANT (SUSPENDED) – A luminaire that is hung from a ceiling by supports.
PERMANENTLY INSTALLED LIGHTING consists of luminaires that are affixed to land, within the
meaning of Civil Code Section 658 and 660, except as provided below. Permanently installed luminaires may
be mounted inside or outside of a building or site. Permanently installed luminaires may have either plug-in or
hardwired connections for electric power. Examples include track and flexible lighting systems; lighting
attached to walls, ceilings, columns, inside or outside of permanently installed cabinets, internally illuminated
Permanently installed lighting does not include portable lighting or lighting that is installed by the manufacturer
in exhaust hoods for cooking equipment, refrigerated cases, food preparation equipment, and scientific and
PORTABLE LIGHTING is lighting, with plug-in connections for electric power, that is: table and
freestanding floor lamps; attached to modular furniture; workstation task luminaires; luminaires attached to
workstation panels; attached to movable displays; or attached to other personal property.
POST TOP LUMINAIRE is an outdoor luminaire that is mounted directly on top of a lamp-post.
PRECISION LIGHTING is task lighting for commercial or industrial work that illuminates low contrast,
finely detailed, or fast moving objects.
RADIANT POWER is the time-rate-flow of radiant energy.
RADIANT ENERGY is energy travelling in the form of electromagnetic waves. It is measured in units of
energy such as joules or kilowatt hours.
RECESSED LUMINAIRE is a luminaire that is mounted in the ceiling or behind a wall or other surface with
the opening of the luminaire flush with the surface.
SCONCE is a wall mounted decorative accent luminaire.
SOURCE (LIGHT) is the general term used to reference a source of light. It can refer variously to an electric
lamp, a light emitting diode (LED), an entire luminaire with lamp and optical control, or fenestration for
SPECIAL EFFECTS LIGHTING is lighting installed to give off luminance instead of providing illuminance,
which does not serve as general, task, or display lighting.
TASK LIGHTING is lighting that is not general lighting and that specifically illuminates a location where a
task is performed.
TEMPORARY LIGHTING is a lighting installation, with plug-in connections, that does not persist beyond 60
consecutive days or more than 120 days per year.
TRACK LIGHTING is a system that includes luminaires and a track, rails, or cables that both mount the
system, and deliver electric power. Track lighting includes the following types:
LINE-VOLTAGE TRACK LIGHTING is equipped with luminaires that, use line-voltage lamps or that
are equipped with integral transformers at each luminaire.
LOW-VOLTAGE TRACK LIGHTING is equipped with remote transformers for use with low-voltage
equipment along the entire length of track.
TRACK LIGHTING INTEGRAL CURRENT LIMITER consists of a current limiter integral to the endfeed
housing of a manufactured line-voltage track lighting system.
TRACK LIGHTING SUPPLEMENTARY OVERCURRENT PROTECTION PANEL is a panelboard
containing Supplementary Overcurrent Protection Devices as defined in Article 100 of the California Electrical
Code, and used only with line voltage track lighting.
TRACK MOUNTED LUMINAIRES are luminaires designed to be attached at any point along a track
lighting system. Track mounted luminaires may be line-voltage or low-voltage.
TUNING is the ability to set maximum light levels at a lower level than full lighting power.
LIGHTING CONTROLS consist of the following:
ASTRONOMICAL TIME-SWITCH CONTROL is an Automatic Time-Switch Control that controls lighting
based on the time of day and astronomical events such as sunset and sunrise, accounting for geographic location and
AUTOMATIC DAYLIGHT CONTROL uses one or more photosensors to detect changes in daylight illumination
and then automatically adjusts the luminous flux of the electric lighting system in response.
AUTOMATIC MULTI-LEVEL DAYLIGHT CONTROL adjusts the luminous flux of the electric lighting
system in either a series of steps or by continuous dimming in response to available daylight. This kind of control
uses one or more photosensors to detect changes in daylight illumination and then automatically adjusts the electric
lighting levels in response.
AUTOMATIC SCHEDULING CONTROL is a time-based lighting control device or system that is capable of
being programmed to turn off outdoor luminaire power for a portion of the night and the day.
AUTOMATIC TIME SWITCH CONTROL controls lighting based on the time of day.
CAPTIVE-KEY OVERRIDE is a type of lighting control in which the key that activates the override cannot be
released when the lights are in the on position.
COUNTDOWN TIMER SWITCH turns lighting or other loads ON when activated using one or more selectable
count-down time periods and then automatically turns lighting or other loads OFF when the selected time period had
DIMMER varies the luminous flux of the electric lighting system by changing the power delivered to that lighting
DIMMER, FULL-RANGE, or Continuous Dimmer, means a dimmer that varies the luminous flux of the electric
lighting system over a continuous range from the device’s maximum light output to the device’s minimum light
output without visually apparent abrupt changes in light level between the various steps.
DIMMER, STEPPED varies the luminous flux of the electric lighting system in one or more predetermined
discrete steps between maximum light output and OFF with changes in light level between adjacent steps being
DIMMER, FORWARD PHASE CUT, varies the luminous flux of the electric lighting system in which a portion of the
alternating current voltage waveform supplying to the light source is removed.
LIGHTING CONTROL, SELF CONTAINED is a unitary lighting control module that requires no additional
components to be a fully functional lighting control.
LIGHTING CONTROL SYSTEM requires two or more components to be installed in the building to provide all
of the functionality required to make up a fully functional and compliant lighting control.
MULTI-LEVEL ASTRONOMICAL TIME SWITCH is an Astronomical Time Switch Control that reduces
lighting power in multiple steps.
MULTI-LEVEL LIGHTING CONTROL reduces power going to a lighting system in multiple steps.
MULTISCENE PROGRAMMABLE CONTROL allows for two or more pre-defined lighting settings, in
addition to all-OFF, for two or more groups of luminaires to suit multiple activities in the space.
NEMA SSL 7A is the National Electrical Manufacturers Association document titled “Phase Cut Dimming for
Solid State Lighting: Basic Compatibility,” 2013. (NEMA SSL 7A-2013).
OCCUPANT SENSING CONTROLS automatically control levels of illumination, allow for manual operation,
and consist of the following types:
MOTION SENSOR is used outdoors, automatically turns lights OFF after an area is vacated of occupants, and
automatically turns the lights ON when the area is occupied.
OCCUPANT SENSOR is used indoors and automatically turns lights OFF after an area is vacated of
occupants and is capable of automatically turning the lighting load ON when an area is occupied.
PARTIAL-ON OCCUPANT/MOTION SENSOR automatically turns lights OFF after an area is vacated of
occupants and is capable of automatically or manually turning ON part of the lighting load when an area is
PARTIAL-OFF OCCUPANT/MOTION SENSOR automatically turns OFF part of the lighting load after an
area is vacated of occupants and is capable of automatically turning ON the lighting load when an area is
VACANCY SENSOR automatically turns lights OFF after an area is vacated of occupants but requires lights
to be turned ON manually.
PART-NIGHT OUTDOOR LIGHTING CONTROL is a light sensing and time-based lighting control device or
system that is programmed to reduce or turn off the lighting power to an outdoor luminaire for a portion of the night.
PHOTO CONTROL automatically turns lights ON and OFF, or automatically adjusts lighting levels, in response
to the amount of daylight that is available. A Photo Control may also be one component of a field assembled lighting
system, the component having the capability to provide a signal proportional to the amount of daylight to a Lighting
Control System to dim or brighten the electric lights in response.
SHUT-OFF CONTROLS is any lighting control capable of automatically shutting OFF the lighting in a space
when the space is typically unoccupied.
LISTED is in accordance with Article 100 of the California Electrical Code.
LOW-GWP REFRIGERANT is a compound used as a heat transfer fluid or gas that is: (A) any compound or
blend of compounds, with a GWP Value less than 150; and (B) U.S. EPA Significant New Alternatives Policy
(SNAP)-approved; and (C) not an ozone depleting substance as defined in Title 40 of the Code of Federal
Regulations, Part 82, §82.3 (as amended March 10, 2009).
LOW-RISE RESIDENTIAL BUILDING is a building, other than a hotel/motel that is Occupancy Group:
R-2, multi-family, with three stories or less; or
R-3, single family; or
U-building, located on a residential site.
LPG is liquefied petroleum gas.
MAKEUP AIR is outdoor air that is intentionally conveyed by openings or ducts into the building from the outside;
is supplied to the vicinity of an exhaust hood; and replaces air, vapor and contaminants being exhausted by the
exhaust hood. Makeup air is generally filtered and fan-forced, and it may be heated or cooled. Makeup air may be
delivered through openings or ducts integral to the exhaust hood.
MANUAL is capable of being operated by personal intervention.
MANUFACTURED DEVICE is any heating, cooling, ventilation, lighting, water heating, refrigeration, cooking,
plumbing fitting, insulation, door, fenestration product, or any other appliance, device, equipment, or system subject
to Sections 110.0 through 110.9 of Part 6.
MANUFACTURED or KNOCKED DOWN PRODUCT is a fenestration product constructed of materials that are
factory cut or otherwise factory formed with the specific intention of being used to fabricate a fenestration product.
Knocked down or partially assembled products may be sold as a fenestration product when provided with temporary
and permanent labels as described in Section 10-111, or as a site-built fenestration product when not provided with
temporary and permanent labels as described in Section 10-111.
MECHANICAL COOLING is lowering the temperature within a space using refrigerant compressors or absorbers,
desiccant dehumidifiers, or other systems that require energy from depletable sources to directly condition the space.
In nonresidential, high-rise residential, and hotel/motel buildings, cooling of a space by direct or indirect evaporation
of water alone is not considered mechanical cooling.
MECHANICAL HEATING is raising the temperature within a space using electric resistance heaters, fossil fuel
burners, heat pumps, or other systems that require energy from depletable sources to directly condition the space.
MERV is the minimum efficiency reporting value as determined by ASHRAE Standard 52.2 Method of Testing
General Ventilation Air-Cleaning Devices for Removal Efficiency by Particle Size.
METAL BUILDING is a complete integrated set of mutually dependent components and assemblies that form a
building, which consists of a steel-framed superstructure and metal skin. This does not include structural glass or
metal panels such as in a curtainwall system.
MICROCHANNEL CONDENSER is an air-cooled condenser for refrigeration systems which utilizes multiple
small parallel gas flow passages in a flat configuration with fin surfaces bonded between the parallel gas passages.
MINISPLIT AIR CONDITIONERS AND HEAT PUMPS are air conditioner or heat pump systems that have a
single outdoor section and one or more indoor sections. The indoor sections cycle on and off in unison in response to
a single indoor thermostat
MODELING ASSUMPTIONS are the conditions (such as weather conditions, thermostat settings and schedules,
internal gain schedules, etc.) that are used for calculating a building’s annual energy consumption as specified in the
Alternative Calculation Methods (ACM) Approval Manuals.
MULTIPLE-SPLIT AIR CONDITIONERS AND HEAT PUMPS are air conditioner or heat pump systems that
have two or more indoor sections. The indoor sections operate independently and can be used to condition multiple
zones in response to multiple indoor thermostats.
MULTIPLE ZONE SYSTEM is an air distribution system that supplies air to more than one Space Conditioning
Zone, each of which has one or more devices (such as dampers, cooling coils, and heating coils) that regulate
airflow, cooling, or heating capacity to the zone.
NET EXHAUST FLOW RATE is the exhaust flow rate for a hood, minus any internal discharge makeup air flow
NEWLY CONDITIONED SPACE is any space being converted from unconditioned to directly conditioned or
indirectly conditioned space. Newly conditioned space must comply with the requirements for an addition. See
Section 141.0 for nonresidential occupancies and Section 150.2 for residential occupancies.
NEWLY CONSTRUCTED BUILDING is a building that has never been used or occupied for any purpose.
NONDUCTED SYSTEM is an air conditioner or heat pump that: is permanently installed; directly heats or cools
air within the conditioned space; and uses one or more indoor coils that are mounted on walls or ceilings within the
conditioned space. The system may be of a modular design that allows for combining multiple outdoor coils and
compressors to create one unified system.
NFRC 100 is the National Fenestration Rating Council document titled “NFRC 100: Procedure for Determining
Fenestration Product U-factors.” (2011; NFRC 100 includes procedures for site fenestration formerly included in a
separate document, NFRC 100-SB).
NFRC 200 is the National Fenestration Rating Council document titled “NFRC 200: Procedure for Determining
Fenestration Product Solar Heat Gain Coefficients and Visible Transmittance at Normal Incidence.” (2011).
NFRC 202 is the National Fenestration Rating Council document titled “NFRC 202: Procedures for Determining
Translucent Fenestration Product Visible Transmittance at Normal Incidence.” (2011).
NFRC 203 is the National Fenestration Rating Council document titled “NFRC 203: Procedure for Determining
Visible Transmittance of Tubular Daylighting Devices.” (2012).
NFRC 400 is the National Fenestration Rating Council document titled “NFRC 400: Procedure for Determining
Fenestration Product Air Leakage.” (2010).
NONRESIDENTIAL BUILDING is any building which is identified in the California Building Code Table;
Description of Occupancy as Group A, B, E, F, H, M, or S; and is a U; as defined by Part 2 of Title24 of the
California Code or Regulation.
NOTE: Requirements for high-rise residential buildings and hotels/motels are included in the nonresidential sections
of Part 6.
NONRESIDENTIAL BUILDING OCCUPANCY TYPES are building types in which a minimum of 90 percent
of the building floor area functions as one of the following, which do not qualify as any other Building Occupancy
Types more specifically defined in Section 100.1, and which do not have a combined total of more than 10 percent of
the area functioning of any Nonresidential Function Areas specifically defined in Section 100.1:
AUDITORIUM BUILDING is a public building in which a minimum of 90 percent of the building floor area
are rooms with fixed seating that are primarily used for public meetings or gatherings.
CLASSROOM BUILDING is a building for an educational institution in which a minimum of 90 percent of
the building floor area are classrooms or educational laboratories.
COMMERCIAL AND INDUSTRIAL STORAGE BUILDING is a building for which a minimum or 90
percent of the building floor area is used for storing items.
CONVENTION CENTER BUILDING is a building in which a minimum of 90 percent of the building floor
area are rooms for meetings and conventions, which have neither fixed seating nor fixed staging.
FINANCIAL INSTITUTION BUILDING is a building in which a minimum of 90 percent of the building
floor area are rooms used for an institution which collects funds from the public and places them in financial
assets, such as deposits, loans, and bonds.
GENERAL COMMERCIAL AND INDUSTRIAL WORK BUILDING is a building in which a minimum of
90 percent of the building floor area are rooms for performing a craft, assembly or manufacturing operation.
GROCERY STORE BUILDING is a building in which a minimum of 90 percent of the building floor area is
sales floor for the sale of foodstuffs.
LIBRARY BUILDING is a building in which a minimum of 90 percent of the building floor area are rooms
use as a repository of literary materials, kept for reading or reference such as books, periodicals, newspapers,
pamphlets and prints.
MEDICAL BUILDINGS AND CLINIC BUILDINGS are non “I” occupancy buildings in which a minimum
of 90 percent of the building floor area are rooms where medical or clinical care is provided, does not provide
overnight patient care, and is used to provide physical and mental care through medical, dental, or psychological
examination and treatment.
OFFICE BUILDING is a building of CBC Group B Occupancy in which a minimum of 90 percent of the
building floor area are rooms in which business, clerical or professional activities are conducted.
PARKING GARAGE BUILDING is a building in which a minimum of 90 percent of the building floor area is
for the purpose of parking vehicles, which consists of at least a roof over the parking area enclosed with walls on
all sides. The building includes areas for vehicle maneuvering to reach designated parking spaces. If the roof of
a parking structure is also used for parking, the section without an overhead roof is considered an outdoor
parking lot instead of a parking garage.
RELIGIOUS FACILITY BUILDING is a building in which a minimum of 90 percent of the floor area in the
building floor area are rooms for assembly of people to worship.
RESTAURANT BUILDING is a building in which a minimum of 90 percent of the building floor area are
rooms in which food and drink are prepared and served to customers in return for money.
SCHOOL BUILDING is a building in which a minimum of 90 percent of the building floor area is used for an
educational institution, but in which less than 90 percent of the building floor area is classrooms or educational
laboratories, and may include an auditorium, gymnasium, kitchen, library, multi-purpose room, cafeteria,
student union, or workroom. A maintenance or storage building is not a school building.
THEATER BUILDING is a building in which a minimum of 90 percent of the building floor area are rooms
having tiers of rising seats or steps for the viewing of motion pictures, or dramatic performances, lectures,
musical events and similar live performances.
NONRESIDENTIAL COMPLIANCE MANUAL is the manual developed by the Commission, under Section
25402.1(e) of the Public Resources Code, to aid designers, builders, and contractors in meeting the energy efficiency
requirements for nonresidential, high-rise residential, and hotel/motel buildings.
NONRESIDENTIAL FUNCTION AREAS are those areas, rooms, and spaces within Nonresidential Buildings which
fall within the following particular definitions, and are defined according to the most specific definition:
AISLE WAY is the passage or walkway between storage racks permanently anchored to the floor in a
Commercial or Industrial Storage Building, where the racks are used to store materials such as goods and
ATRIUM is a large-volume indoor space created by openings between two or more stories but is not used for an
enclosed stairway, elevator hoistway, escalator opening, or utility shaft for plumbing, electrical, air-conditioning
or other equipment.
AUDITORIUM ROOM is a room with fixed seats used for public meetings or gatherings.
AUTO REPAIR BAY is a room or area used to repair automotive equipment and/or vehicles.
BEAUTY SALON is a room or area in which the primary activity is manicures, pedicures, facials, or the
cutting or styling of hair.
CIVIC MEETING PLACE is a space in a government building designed or used for public debate, discussion,
or public meetings of governmental bodies.
CLASSROOM, LECTURE, TRAINING, VOCATIONAL ROOM is a room or area where an audience or
class receives instruction.
COMMERCIAL AND INDUSTRIAL STORAGE AREA is a room or area used for storing of items such as
goods and merchandise.
COMMERCIAL AND INDUSTRIAL STORAGE AREA (REFRIGERATED) is a room or area used for
storing items where mechanical refrigeration is used to maintain the space temperature at 55° F or less.
CONVENTION, CONFERENCE, AND MEETING CENTERS are rooms or areas that are designed or used
for meetings, conventions or events, and that have neither fixed seating nor fixed staging.
CORRIDOR is a passageway or route into which compartments or rooms open.
DINING is a room or area where meals that are served to the customers will be consumed.
ELECTRICAL/MECHANICAL/TELEPHONE ROOM is a room in which the building’s electrical
switchbox or control panels, telephone switchbox, and/or HVAC controls or equipment is located.
EXERCISE CENTER OR GYMNASIUM is a room or area equipped for gymnastics, exercise equipment, or
indoor athletic activities.
EXHIBIT, MUSEUM AREA is a room or area in a museum that has for its primary purpose exhibitions,
having neither fixed seating nor fixed staging. An exhibit does not include a gallery or other place where art is
for sale. An exhibit does not include a lobby, conference room, or other occupancies where the primary function
is not exhibitions.
FINANCIAL TRANSACTION AREA is a room or area used by an institution which collects funds from the
public and places them in financial assets, such as deposits, loans and bonds, and includes tellers, work stations,
and customers’ waiting areas; to complete financial transactions. Financial transaction areas do not include
private offices, hallways, restrooms, or other support areas.
GENERAL COMMERCIAL AND INDUSTRIAL WORK AREA is a room or area in which an art, craft,
assembly or manufacturing operation is performed. Lighting installed in these areas is classified as follows:
HIGH BAY: Where the luminaires are 25 feet or more above the floor.
LOW BAY: Where the luminaires are less than 25 feet above the floor.
PRECISION: Where visual tasks of small size or fine detail such as electronics assembly, fine
woodworking, metal lathe operation, fine hand painting and finishing, egg processing operations, or tasks of
similar visual difficulty are performed.
GROCERY SALES AREA is a room or area that has as its primary purpose the sale of foodstuffs requiring
additional preparation prior to consumption.
HOTEL FUNCTION AREA is a hotel room or area such as a hotel ballroom, meeting room, exhibit hall or
conference room, together with pre-function areas and other spaces ancillary to its function.
KITCHEN/FOOD PREPARATION is a room or area with cooking facilities or an area where food is
LABORATORY, SCIENTIFIC is a room or area where research, experiments, and measurement in medical
and physical sciences are performed requiring examination of fine details. The area may include workbenches,
countertops, scientific instruments, and associated floor spaces. Scientific laboratory does not refer to film,
computer, and other laboratories where scientific experiments are not performed.
LAUNDRY is a room or area primarily designed or used for laundering activities.
LIBRARY AREA is a room or area primarily designed or used as a repository for literary materials, such as
books, periodicals, newspapers, pamphlets and prints, kept for reading or reference.
READING AREA is a room or area in a library containing tables, chairs, or desks for patrons to use for the
purpose of reading books and other reference documents. Library reading areas include reading, circulation
and checkout areas. Reading areas do not include private offices, meeting, photocopy, or other rooms not
used specifically for reading by library patrons.
STACK AREA is a room or area in a library with grouping of shelving sections. Stack aisles include
pedestrian paths located in stack areas.
LOBBY, HOTEL is the contiguous area in a hotel/motel between the main entrance and the front desk,
including reception, waiting and seating areas.
MAIN ENTRY is the contiguous area in buildings other than hotel/motel that is directly located by the
main entrance of the building through which persons must pass, including any ancillary reception, waiting
and seating areas.
LOCKER OR DRESSING ROOM is a room or area for changing clothing, sometimes equipped with lockers.
LOUNGE is a room or area in a public place such as a hotel, airport, club, or bar, designated for people to sit,
wait and relax.
MALL is a roofed or covered common pedestrian area within a mall building that serves as access for two or
MEDICAL AND CLINICAL CARE AREA is a non “I” occupancy room or area in a building that does not
provide overnight patient care and that is used to provide physical and mental care through medical, dental, or
psychological examination and treatment, including, but not limited to, laboratories and treatment spaces.
MUSEUM is a room or area in which the primary function is the care or exhibit of works of artistic, historical,
or scientific value. A museum does not include a gallery or other place where art is for sale. A museum does not
include a lobby, conference room, or other occupancies where the primary function is not the care or exhibit of
works of artistic, historical, or scientific value.
OFFICE AREA is a room, area in a building of CBC Group B Occupancy in which business, clerical or
professional activities are conducted.
OPEN AREA is a warehouse facility term describing a large unobstructed area that is typically used for the
handling and temporary storage of goods.
PARKING GARAGE AREAS include the following:
PARKING AREAS are the areas of a Parking Garage used for the purpose of parking and maneuvering of
vehicles on a single floor. Parking areas include sloping floors of a parking garage. Parking areas do not
include Daylight Transition Zones, Dedicated Ramps, or the roof of a Parking Garage, which may be
present in a Parking Garage.
DAYLIGHT TRANSITION ZONE in a Parking Garage is the interior path of travel for vehicles to enter a
parking garage as needed to transition from exterior daylight levels to interior light levels. Daylight
Transition Zones only include the path of vehicular travel and do not include adjacent Parking Areas.
DEDICATED RAMPS in Parking Garages are driveways specifically for the purpose of moving vehicles
between floors of a parking garage and which have no adjacent parking. Dedicated ramps do not include
sloping floors of a parking structure, which are considered Parking Areas.
RELIGIOUS WORSHIP AREA is a room or area in which the primary function is for an assembly of people
to worship. Religious worship does not include classrooms, offices, or other areas in which the primary function
is not for an assembly of people to worship.
RESTROOM is a room providing personal facilities such as toilets and washbasins.
RETAIL MERCHANDISE SALES AREA is a room or area in which the primary activity is the sale of
SERVER ROOM is a room smaller than 500 square feet, within a larger building, in which networking
equipment and Information Technology (IT) server equipment is housed, and a minimum of five IT severs are
installed in frame racks.
SERVER AISLE is an aisle of racks of Information Technology (IT) server equipment in a Server Room.
While networking equipment may also be housed on these racks, it is largely a room to manage server
STAIRS is a series of steps providing passage for persons from one level of a building to another, including
STAIRWELL is a vertical shaft in which stairs are located.
SUPPORT AREA is a room or area used as a passageway, utility room, storage space, or other type of space
associated with or secondary to the function of an occupancy that is listed in these regulations.
TENANT LEASE AREA is a room or area in a building intended for lease for which a specific tenant is not
identified at the time of building permit application.
THEATER AREAS include the following:
MOTION PICTURE THEATER is an assembly room or area with tiers of rising seats or steps for the
showing of motion pictures.
PERFORMANCE THEATER is an assembly room or area with tiers of rising seats or steps for the
viewing of dramatic performances, lectures, musical events and similar live performances.
TRANSPORTATION FUNCTION AREA is the ticketing area, waiting area, baggage handling areas,
concourse, in an airport terminal, bus or rail terminal or station, subway or transit station, or a marine terminal.
VIDEOCONFERENCING STUDIO is a room with permanently installed videoconferencing cameras, audio
equipment, and playback equipment for both audio-based and video-based two-way communication between
local and remote sites.
VOCATIONAL AREA is a room or area used to provide training in a special skill to be pursued as a trade.
WAITING AREA is an area other than a hotel lobby or main entry lobby normally provided with seating and
used for people waiting.
WHOLESALE SHOWROOM is a room or area where samples of merchandise are displayed.
NONSTANDARD PART LOAD VALUE (NPLV) is a single- number part-load efficiency figure of merit for
chillers referenced to conditions other than IPLV conditions. (See “integrated part load value.”)
NORTH-FACING (See “orientation.”)
OCCUPIABLE SPACE is any enclosed space inside the pressure boundary and intended for human activities,
including, but not limited to, all habitable spaces, toilets, closets, halls, storage and utility areas, and laundry areas.
ONLINE CAPACITY is the total combined capacity in actual cubic feet per minute of compressed air at a given
pressure from all online compressors.
ONLINE COMPRESSORS are all the compressors that are physically connected to compressed air piping and are
available to serve peak load. Online compressors do not include back up compressors whose only purpose is to be
available when an online compressor fails.
OPEN COOLING TOWER is an open, or direct contact, cooling tower which exposes water directly to the cooling
atmosphere, thereby transferring the source heat load from the water directly to the air by a combination of heat and
OPERABLE FENESTRATION is designed to be opened or closed.
OPTIMUM START CONTROLS are controls that are designed to automatically adjust the start time of a space
conditioning system each day with the intent of bringing the space to desired occupied temperature levels at the
beginning of scheduled occupancy.
OPTIMUM STOP CONROLS are controls that are designed to setup or setback thermostat setpoints before
scheduled unoccupied periods based upon the thermal lag and acceptable drift in space temperature that is within
ORIENTATION, CARDINAL is one of the four principal directional indicators, north, east, south, and west,
which are marked on a compass, also called cardinal directions.
ORIENTATION, EAST-FACING is oriented to within 45 degrees of true east, including 45°00’00” south of east
(SE), but excluding 45°00’00” north of east (NE).
ORIENTATION, NORTH-FACING is oriented to within 45 degrees of true north, including 45°00’00” east of
north (NE), but excluding 45°00’00’ west of north (NW).
ORIENTATION, SOUTH-FACING is oriented to within 45 degrees of true south including 45°00’00” west of
south (SW), but excluding 45°00’00” east of south (SE).
ORIENTATION, WEST-FACING is oriented to within 45 degrees of true west, including 45°00’00” north of due
west (NW), but excluding 45°00’00” south of west (SW).
OUTDOOR AIR (Outside air) is air taken from outdoors and not previously circulated in the building.
OUTDOOR LIGHTING is electrical lighting used to illuminate outdoor areas.
OUTDOOR AREAS are areas external to a building. These include but are not limited to the following areas:
BUILDING ENTRANCE WAY is the external area of any operable doorway in or out of a building, including
overhead doors. These areas serve any doorway, set of doors (including elevator doors such as in parking
garages), turnstile, vestibule, or other form of portal that is ordinarily used to gain access to the building by its
users and occupants. Where buildings have separate one-way doors to enter and to leave, this also includes any
area serving any doors ordinarily used to leave the building.
BUILDING FAÇADE is the exterior surfaces of a building, not including horizontal roofing, signs, and
surfaces not visible from any public accessible viewing location.
CANOPY is a permanent structure, other than a parking garage area, consisting of a roof and supporting
building elements, with the area beneath at least partially open to the elements. A canopy may be freestanding or
attached to surrounding structures. A canopy roof may serve as the floor of a structure above.
CARPORT is a covered, open-sided structure designed or used primarily for the purpose of parking vehicles,
having a roof over the parking area. Typically, carports are free-standing or projected from the side of the
building and are only two or fewer car lengths deep. A Carport is not a Garage.
HARDSCAPE is the area of an improvement to a site that is paved or has other structural features such as
curbs, plazas, entries, parking lots, site roadways, driveways, walkways, sidewalks, bikeways, water features and
pools, storage or service yards, loading docks, amphitheaters, outdoor sales lots, and private monuments and
OUTDOOR SALES FRONTAGE is the portion of the perimeter of an outdoor sales area immediately
adjacent to a public street, road, or sidewalk.
OUTDOOR SALES LOT is an uncovered paved area used exclusively for the display of vehicles, equipment
or other merchandise for sale. All internal and adjacent access drives, walkway areas, employee and customer
parking areas, vehicle service or storage areas are not outdoor sales lot areas, but are considered hardscape.
PARKING LOT is an uncovered area for the purpose of parking vehicles. Parking lot is a type of hardscape.
PAVED AREA is an area that is paved with concrete, asphalt, stone, brick, gravel, or other improved wearing
surface, including the curb.
PRINCIPAL VIEWING LOCATION is anywhere along the adjacent highway, street, road or sidewalk
running parallel to an outdoor sales frontage.
PUBLIC MONUMENTS are statuary, buildings, structures, and/or hardscape on public land.
OUTDOOR SALES CANOPY is a canopy specifically to cover and protect an outdoor sales area.
STAIRWAYS AND RAMPS. Stairways are one or more flights of stairs with the necessary landings and
platforms connecting them to form a continuous and uninterrupted passage from one level to another. An
exterior stairway is open on at least one side, except for required structural columns, beams, handrails and
guards. The adjoining open areas shall be either yards, courts or public ways. The other sides of the exterior
stairway need not be open. Ramps are walking surfaces with a slope steeper than 5 percent.
VEHICLE SERVICE STATION is a gasoline, natural gas, diesel, or other fuel dispensing station.
OUTDOOR LIGHTING ZONE is a geographic area designated by the California Energy Commission in
accordance with Part 1, Section 10-114, that determines requirements for outdoor lighting, including lighting power
LZ2, LZ3 and LZ4.
OVERHANG is a contiguous opaque surface, oriented horizontally and projecting outward horizontally from an
exterior vertical surface.
OVERHANG OFFSET is the vertical distance from the edge of exposed exterior glazing at the head of a window
to the overhang.
OVERHANG PROJECTION is the horizontal distance, measured outward horizontally from the surface of
exposed exterior glazing at the head of a window to the outward edge of an overhang.
PART 1 means Part 1 of Title 24 of the California Code of Regulations.
PART 6 means Part 6 of Title 24 of the California Code of Regulations.
PART LOAD OPERATION occurs when a system or device is operating below its maximum rated capacity.
PARTICLE SIZE EFFICIENCY is the fraction (percentage) of particles that are captured on air filter equipment
as determined during rating tests conducted in accordance with ASHRAE Standard 52.2 or AHRI Standard 680.
Particle Size Efficiency is measured in three particle size ranges: 0.3-1.0, 1.0-3.0, 3.0-10 microns.
POOLS, ANSI/NSPI-5 is the American National Standards Institute and National Spa and Pool Institute document
titled “American National Standard for Residential Inground Swimming Pools” 2003 (ANSI/NSPI-5 2003).
POOLS, AUXILIARY POOL LOADS are features or devices that circulate pool water in addition to that required
for pool filtration, including, but not limited to, solar pool heating systems, filter backwashing, pool cleaners,
waterfalls, fountains, and spas.
POOLS, BACKWASH VALVE is a diverter valve designed to backwash filters located between the circulation
pump and the filter, including, but not limited to, slide, push-pull, multi-port, and full-flow valves.
POOLS, MULTISPEED PUMP is a pump capable of operating at two or more speeds and includes two-speed and
POOLS, NSF/ANSI 50 is the NSF International (formerly National Sanitation Foundation) Standard and American
National Standards Institute document titled “Circulation System Components and Related Materials for Swimming
Pools, Spas/Hot Tubs” 2005 (NSF/ANSI 50 – 2005).
POOLS, RESIDENTIAL are permanently installed residential in-ground swimming pools intended for use by a
single-family home for noncommercial purposes and with dimensions as defined in ANSI/NSPI-5.
PRESSURE BOUNDARY is the primary air enclosure boundary separating indoor and outdoor air. For example, a
volume that has more leakage to the outside than to the conditioned space would be considered outside the pressure
boundary. Exposed earth in a crawlspace or basement shall not be considered part of the pressure boundary.
PRIMARY AIRFLOW is the airflow (cfm or L/s) supplied to the zone from the air-handling unit at which the
outdoor air intake is located. It includes outdoor intake air and recirculated air from that air-handling unit but does
not include air transferred or air recirculated to the zone by other means.
PRIMARY STORAGE is compressed air storage located upstream of the distribution system and any pressure flow
PROCESS is an activity or treatment that is not related to the space conditioning, lighting, service water heating, or
ventilating of a building as it relates to human occupancy.
PROCESS BOILER is a type of boiler with a capacity (rated maximum input) of 300,000 Btus per hour (Btu/h) or
more that serves a process.
PROCESS, COVERED are processes that are regulated under Part 6, serving computer rooms, data centers,
elevators, escalators and moving walkways, laboratories, enclosed parking garages, commercial kitchens,
refrigerated warehouses, commercial refrigeration, compressed air systems, and process boilers.
PROCESS, EXEMPT is a process that is not a covered process.
PROCESS LOAD is a load resulting from a process.
PROCESS LOAD, COVERED the energy consumption of and/or the heat generated by a piece of equipment or
device that is part of a covered process.
PROCESS LOAD, EXEMPT is the energy consumption of and/or the heat generated by a piece of equipment or
device that is part of an exempt process.
PROCESS SPACE is a space that is thermostatically controlled to maintain a process environment temperature less
than 55º F or to maintain a process environment temperature greater than 90º F for the whole space that the system
serves, or that is a space with a space-conditioning system designed and controlled to be incapable of operating at
temperatures above 55º F or incapable of operating at temperatures below 90º F at design conditions.
PROPOSED DESIGN BUILDING ENERGY USE is the predicted energy use of proposed building derived from
application of the building energy use modeling rules described in the Alternative Calculation Method (ACM)
PUBLIC AREAS are spaces generally open to the public at large, customers or congregation members, or similar
spaces where occupants need to be prevented from controlling lights for safety, security, or business reasons.
R-VALUE is the measure of the thermal resistance of insulation or any material or building component expressed in
RADIANT BARRIER is a highly reflective, low emitting material installed at the underside surface of the roof
deck and the inside surface of gable ends or other exterior vertical surfaces in attics to reduce solar heat gain.
RAISED FLOOR is a floor (partition) over a crawl space, or an unconditioned space, or ambient air.
READILY ACCESSIBLE is capable of being reached quickly for operation, repair or inspection, without requiring
climbing or removing obstacles, or resorting to access equipment.
RECOOL is the cooling of air that has been previously heated by space-conditioning equipment or systems serving
the same building.
RECOVERED ENERGY is energy used in a building that (1) is recovered from space conditioning, service water
heating, lighting, or process equipment after the energy has performed its original function; (2) provides space
conditioning, service water heating, or lighting; and (3) would otherwise be wasted.
REFERENCE APPENDICES is the support document for the Building Energy Efficiency Standards and the ACM
Approval Manuals. The document consists of three sections: the Reference Joint Appendices (JA), the Reference
Residential Appendices (RA), and the Reference Nonresidential Appendices (NA).
REFLECTANCE, SOLAR is the ratio of the reflected solar flux to the incident solar flux.
REFRIGERATED CASE is a manufactured commercial refrigerator or freezer, including but not limited to display
cases, reach-in cabinets, meat cases, and frozen food and soda fountain units.
REFRIGERATED SPACE is a space constructed for storage or handling of products, where mechanical
refrigeration is used to maintain the space temperature at 55° F or less.
REFRIGERATED WAREHOUSE is a building or a space greater than or equal to 3,000 square feet constructed
for storage or handling of products, where mechanical refrigeration is used to maintain the space temperature at 55°
F or less.
REHEAT is the heating of air that has been previously cooled by cooling equipment or supplied by an economizer.
RELOCATABLE PUBLIC SCHOOL BUILDING is a relocatable building as defined by Title 24, Part 1, Section
4-314, which is subject to Title 24, Part 1, Chapter 4, Group 1.
REPAIR is the reconstruction or renewal for the purpose of maintenance of any component, system, or equipment of
an existing building. Repairs shall not increase the preexisting energy consumption of the repaired component,
system, or equipment. Replacement of any component, system, or equipment for which there are requirements in the
Standards is considered an alteration and not a repair.
REPLACEMENT AIR is air that is used to replace air removed from a building through an exhaust system.
Replacement air may be derived from one or more of the following: makeup air, portions of supply air, transfer air,
or infiltration air.
SUPPLY AIR is air entering a space from an air-conditioning, heating, or ventilating system for the purpose of
comfort conditioning. Supply air is generally filtered, fan-forced, and heated, cooled, humidified or dehumidified as
necessary to maintain specified temperature and humidity conditions.
TRANSFER AIR is air transferred, whether actively by fans or passively by pressure differentials, from one room
to another within a building through openings in the room envelope.
INFILTRATION AIR is outdoor air that enters a building or space through openings in the building or space
envelope due to negative pressure in the space or building relative to the exterior of the building envelope.
RESIDENTIAL BUILDING (See “high-rise residential building” and “low-rise residential building.”)
RESIDENTIAL COMPLIANCE MANUAL is the manual developed by the Commission, under Section 25402.1
of the Public Resources Code, to aid designers, builders, and contractors in meeting Energy Efficiency Standards for
low-rise residential buildings.
RESIDENTIAL SPACE TYPE is one of the following:
BATHROOM is a room or area containing a sink used for personal hygiene, toilet, shower, or a tub.
CLOSET is a nonhabitable room used for the storage of linens, household supplies, clothing, non-perishable
food, or similar uses, and which is not a hallway or passageway.
GARAGE is a nonhabitable building or portion of building, attached to or detached from a residential dwelling
unit, in which motor vehicles are parked.
KITCHEN is a room or area used for cooking, food storage and preparation and washing dishes, including
associated counter tops and cabinets, refrigerator, stove, ovens, and floor area.
LAUNDRY is a nonhabitable room or space which contains plumbing and electrical connections for a washing
machine or clothes dryer.
STORAGE BUILDING is a nonhabitable detached building used for the storage of tools, garden equipment, or
UTILITY ROOM is a nonhabitable room or building which contains only HVAC, plumbing, or electrical
controls or equipment; and which is not a bathroom, closet, garage, or laundry room.
ROOF is the outside cover of a building or structure including the structural supports, decking, and top layer that is
exposed to the outside with a slope less than 60 degrees from the horizontal.
ROOF, LOW-SLOPED is a roof that has a ratio of rise to run of 2:12 or less (9.5 degrees from the horizontal).
ROOF, STEEP-SLOPED is a roof that has a ratio of rise to run of greater than 2:12 (9.5 degrees from the
ROOFING PRODUCT is the top layer of the roof that is exposed to the outside, which has properties including but
not limited to solar reflectance, thermal emittance, and mass.
ROOF RECOVER BOARD is a rigid type board, installed directly below a low-sloped roof membrane, with or
without above deck thermal insulation, to: (a) improve a roof system’s compressive strength, (b) physically separate
the roof membrane from the thermal insulation, or (c) physically separate a new roof covering from an underlying
roof membrane as part of a roof overlay project.
RUNOUT is piping that is no more than 12 feet long and connects to a fixture or an individual terminal unit.
SATURATED CONDENSING TEMPERATURE (also known as CONDENSING TEMPERATURE) is: (a)
for single component and azeotropic refrigerants, the saturation temperature corresponding to the refrigerant pressure
at the condenser entrance, or (b) for zeotropic refrigerants, the arithmetic average of the Dew Point and Bubble Point
temperatures corresponding to the refrigerant pressure at the condenser entrance.
SCIENTIFIC EQUIPMENT is measurement, testing or metering equipment used for scientific research or
investigation, including but not limited to manufactured cabinets, carts and racks.
SEASONAL ENERGY EFFICIENCY RATIO (SEER) is the total cooling output of an air conditioner in Btu
during its normal usage period for cooling divided by the total electrical energy input in watt-hours during the same
period, as determined using the applicable test method in the Appliance Efficiency Regulations.
SERVICE WATER HEATING is heating of water for sanitary purposes for human occupancy, other than for
SHADING is the protection from heat gains because of direct solar radiation by permanently attached exterior
devices or building elements, interior shading devices, glazing material, or adherent materials.
SHADING COEFFICIENT (SC) is the ratio of the solar heat gain through a fenestration product to the solar heat
gain through an unshaded 1/8-inch-thick clear double strength glass under the same set of conditions. For
nonresidential, high-rise residential, and hotel/motel buildings, this shall exclude the effects of mullions, frames,
sashes, and interior and exterior shading devices.
SIGN definitions include the following:
ELECTRONIC MESSAGE CENTER (EMC) is a pixilated image producing electronically controlled sign
formed by any light source. Bare lamps used to create linear lighting animation sequences through the use of
chaser circuits, also known as “chaser lights” are not considered an EMC.
ILLUMINATED FACE is a side of a sign that has the message on it. For an exit sign it is the side that has the
word “EXIT” on it.
SIGN, CABINET is an internally illuminated sign consisting of frame and face, with a continuous translucent
message panel, also referred to as a panel sign.
SIGN, CHANNEL LETTER is an internally illuminated sign with multiple components, each built in the
shape of an individual three dimensional letters or symbol that are each independently illuminated, with a
separate translucent panel over the light source for each element.
SIGN, DOUBLE-FACED is a sign with two parallel opposing faces.
SIGN, EXTERNALLY ILLUMINATED is any sign or a billboard that is lit by a light source that is external
to the sign directed towards and shining on the face of the sign.
SIGN, INTERNALLY ILLUMINATED is a sign that is illuminated by a light source that is contained inside
the sign where the message area is luminous, including cabinet signs and channel letter signs.
SIGN, TRAFFIC is a sign for traffic direction, warning, and roadway identification.
SIGN, UNFILTERED is a sign where the viewer perceives the light source directly as the message, without
any colored filter between the viewer and the light source, including neon, cold cathode, and LED signs.
SINGLE FAMILY RESIDENCE is a building that is of Occupancy Group R-3.
SINGLE PACKAGE VERTICAL AIR CONDITIONER (SPVAC): Is a type of air-cooled small or large
commercial package air-conditioning and heating equipment; factory assembled as a single package having its major
components arranged vertically, which is an encased combination of cooling and optional heating components; is
intended for exterior mounting on, adjacent interior to, or through an outside wall; and is powered by single or threephase
current. It may contain separate indoor grille, outdoor louvers, various ventilation options, indoor free air
discharge, ductwork, wall plenum, or sleeve. Heating components may include electrical resistance, steam, hot water,
gas, or no heat but may not include reverse cycle refrigeration as a heating means.
SINGLE PACKAGE VERTICAL HEAT PUMP (SPVHP): Is an SPVAC that utilizes reverse cycle refrigeration
as its primary heat source, with secondary supplemental heating by means of electrical resistance, steam, hot water,
SINGLE ZONE SYSTEM is an air distribution system that supplies air to one thermal zone.
SITE-BUILT is fenestration designed to be field-glazed or field assembled units using specific factory cut or
otherwise factory formed framing and glazing units that are manufactured with the intention of being assembled at
the construction site. These include storefront systems, curtain walls and atrium roof systems.
SITE SOLAR ENERGY is thermal, chemical, or electrical energy derived from direct conversion of incident solar
radiation at the building site.
SKYLIGHT is fenestration installed on a roof less than 60 degrees from the horizontal.
SKYLIGHT AREA is the area of the rough opening for the skylight.
SKYLIGHT TYPE is one of the following three types of skylights: glass mounted on a curb, glass not mounted on
a curb or plastic (assumed to be mounted on a curb).
SMACNA is the Sheet Metal and Air-Conditioning Contractors National Association.
SMACNA HVAC DUCT CONSTRUCTION STANDARDS is the Sheet Metal Contractors’ National Association
document “HVAC Duct Construction Standards Metal and Flexible – 3rd Edition,” 2006 (2006ANSI/SMACNA-006-
2006 HVAC Duct Construction Standards Metal and Flexible 3rd Edition)
SMACNA RESIDENTIAL COMFORT SYSTEM INSTALLATION STANDARDS MANUAL is the Sheet
Metal Contractors’ National Association document titled “Residential Comfort System Installation Standards
Manual, Seventh Edition.” (1998).
SOCIAL SERVICES BUILDING is a space where public assistance and social services are provided to individuals
SOLAR REFLECTANCE INDEX (SRI) is a measure of the roof’s ability to reject solar heat which includes both
reflectance and emittance.
SOLAR SAVINGS FRACTION (SSF) is the fraction of domestic hot water demand provided by a solar waterheating
SOLAR ZONE is a section of the roof designated and reserved for the future installation of a solar electric or solar
SOUTH-FACING (See “orientation.”)
SPA is a vessel that contains heated water in which humans can immerse themselves, is not a pool, and is not a
SPACE-CONDITIONING SYSTEM is a system that provides heating, or cooling within or associated with
conditioned spaces in a building, and may incorporate use of components such as chillers/compressors, fluid
distribution systems (e.g., air ducts, water piping, refrigerant piping), pumps, air handlers, cooling and heating coils,
air or water cooled condensers, economizers, terminal units, and associated controls.
SPANDREL is opaque glazing material most often used to conceal building elements between floors of a building
so they cannot be seen from the exterior, also known as “opaque in-fill systems.”
STANDARD DESIGN BUILDING is a building that complies with the mandatory and prescriptive requirements in
the Title 24 Building Energy Efficiency Standards by using the building energy modeling rules described in the
Alternative Calculation Method (ACM) Reference Manual.
STORAGE, COLD, is a storage area within a refrigerated warehouse where space temperatures are maintained at or
above 32° F.
STORAGE, FROZEN is a storage area within a refrigerated warehouse where the space temperatures are
maintained below 32° F.
TENANT SPACE is a portion of a building occupied by a tenant.
THERMAL MASS is solid or liquid material used to store heat for later heating use or for reducing cooling
THERMAL RESISTANCE (R) is a measurement of the resistance over time of a material or building component
to the passage of heating (hr x ft² x ºF)/Btu.
THERMOSTAT is an automatic control device or system used to maintain temperature at a fixed or adjustable
THERMOSTATIC EXPANSION VALVE (TXV) is a refrigerant metering valve, installed in an air conditioner or
heat pump, which controls the flow of liquid refrigerant entering the evaporator in response to the superheat of the
gas leaving it.
TIME DEPENDENT VALUATION (TDV) ENERGY is the time varying energy caused to be used by the
building to provide space conditioning and water heating and for specified buildings lighting. TDV energy accounts
for the energy used at the building site and consumed in producing and in delivering energy to a site, including, but
not limited to, power generation, transmission and distribution losses.
TINTED GLASS is colored glass by incorporation of a mineral admixture resulting in a degree of tinting. Any
tinting reduces both visible and radiant transmittance.
TOTAL HEAT OF REJECTION (THR) is the heat rejected by refrigeration system compressors at design
conditions, consisting of the design cooling capacity plus the heat of compression added by the compressors.
TOWNHOUSE is a single-family dwelling unit constructed in a group of three or more attached units in which each
unit extends from the foundation to roof and with open space on at least two sides.
TRANSFER AIR is air transferred, whether actively by fans or passively by pressure differentials, from one room
to another within a building through openings in the room envelope.
TRIM COMPRESSOR is a compressor that is designated for part-load operation, handling the short term variable
trim load of end uses, in addition to the fully loaded base compressors.
U-FACTOR is the overall coefficient of thermal transmittance of a fenestration, wall, floor, or roof/ceiling
component, in Btu/(hr x ft² x ºF), including air film resistance at both surfaces.
UL is the Underwriters Laboratories.
UL 727 is the Underwriters Laboratories document titled “Standard for Oil-Fired Central Furnaces,” 2006.
UL 731 is the Underwriters Laboratories document titled “Standard for Oil-Fired Unit Heaters,” 2006 with revision
1 through 7.UL 1574 is the Underwriters Laboratories document entitled “Track Lighting Systems,” 2000.
UL 1598 is the Underwriters Laboratories document titled “Luminaires,” 2008.
UNCONDITIONED SPACE is enclosed space within a building that is not directly conditioned, or indirectly
UNIT INTERIOR MASS CAPACITY (UIMC) is the amount of effective heat capacity per unit of thermal mass,
taking into account the type of mass material, thickness, specific heat, density and surface area.
USDOE 10 CFR 430 is the regulation issued by Department of Energy and available in the Code of Federal
Regulation – Title 10, Chapter II, Sub-chapter D, Part 430 – Energy Conservation Program for Consumer Products.
Relevant testing methodologies are specified in “Appendix N to sub-part B of Part 430 – Uniform test method for
measuring the energy consumption of furnaces and boilers.”
USDOE 10 CFR 431 is the regulation issued by Department of Energy and available in the Code of Federal
Regulation – Title 10, Chapter II, Sub-chapter D, Part 431 – Energy Conservation Program for Certain Commercial
and Industrial equipment. Relevant testing methodologies are specified in “Subpart E to Part 431 – Uniform test
method for the measurement of energy efficiency of commercial packaged boilers.”
VAPOR RETARDER CLASS is a measure of the ability of a material or assembly to limit the amount of moisture
that passes through the material or assembly meeting Section 202 of the California Building Code.
VARIABLE AIR VOLUME (VAV) SYSTEM is a space-conditioning system that maintains comfort levels by
varying the volume of supply air to the zones served.
VENDING MACHINE is a machine for vending and dispensing refrigerated or non-refrigerated food and
beverages or general merchandise.
VERY VALUABLE MERCHANDISE is rare or precious objects, including, but not limited to, jewelry, coins,
small art objects, crystal, ceramics, or silver, the selling of which involves customer inspection of very fine detail
from outside of a locked case.
WALL TYPE is a type of wall assembly having a specific heat capacity, framing type, and U-factor.
WATER BALANCE IN EVAPORATIVE COOLING TOWERS The water balance of a cooling tower is:
M = E + B, where:
M = makeup water (from the mains water supply)
E = losses due to evaporation
B = losses due to blowdown
WEST-FACING (See “orientation”)
WINDOW FILM is fenestration attachment products which consist of a flexible adhesive-backed polymer film
which may be applied to the interior or exterior surface of an existing glazing system.
WOOD HEATER is an enclosed wood-burning appliance used for space heating and/or domestic water heating.
WOOD STOVE (See “wood heater.”)
ZONE, CRITICAL is a zone serving a process where reset of the zone temperature setpoint during a demand shed
event might disrupt the process, including but not limited to computer rooms, data centers, telecom and private
branch exchange (PBX) rooms, and laboratories.
ZONE, NON-CRITICAL is a zone that is not a critical zone.
ZONE, SPACE-CONDITIONING, is a space or group of spaces within a building with sufficiently similar
comfort conditioning requirements so that comfort conditions, as specified in Section 140.4(b)3 or 150.0(h), as
applicable, can be maintained throughout the zone by a single controlling device.