A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z


Ancillary learning spaces: Spaces for which the primary educational functions are informal learning, social interaction or similar activity other than formal instruction. These areas include, but are not limited to, corridors, cafeterias, gymnasia, and indoor swimming pools.   

ANSI/ASA: ANSI/ASA S1.1-2013, published by the American National Standards Institute (ANSI), is the current American National Standard on Acoustical Terminology 

ASHRAE: American Society of Heating, Refrigeration and Air Conditioning Engineers. An international technical society organized to advance the arts and sciences of heating, ventilation, air conditioning, and cooling to serve humanity and promote a sustainable world.  ASHRAE Standards cited by the CHPS Core Criteria include ASHRAE 55, Thermal Environmental Conditions for Human Occupancy; ASHRAE 62.1 Ventilation Standards for Acceptable Indoor Air Quality; and ASHRAE 90.1, Energy Standard for Buildings, Except Low-Rise Residential Buildings. 


Benchmarking: Benchmarking is a way to measure performance of a single building over time, relative to other similar buildings, or to modeled simulations of a reference building built to a specific standard. The point of benchmarking is to identify internal opportunities for improvement. 

Biophilia: Biophilia is the term coined by Harvard naturalist Dr. Edward O. Wilson to describe what he saw ahumanity's innate tendency to be drawn toward nature and to feel an affinity for it. 

Biophilic Design: Biophilic design is a concept used within the building industry to increase occupant connectivity to the natural environment through the use of direct nature, indirect nature, and space and place conditions 


CALGreen: California Green Building Code or Title 24, California Code of Regulations, Part 11.  

CalRecycle: California's Department of Resources Recycling and Recovery  

CEE: Consortium for Energy Efficiency (CEE) is an EPA Climate Protection Award-winning consortium of efficiency program administrators from the United States and Canada. Members work to unify program approaches across jurisdictions to increase the success of efficiency in markets. CEE labels on products show that they meet a certain tier of CEE initiatives. Learn more here. 

CRI: 1) Carpet and Rug Institute, 2) Color Rendering Index, the measurement of a light sources ability to accurately render a sampling of different colors, as represented by a scale from 1-100.   

CFR: Code of Federal Regulations  

CHPS®: Collaborative for High Performance Schools®, Inc., a national 501(c)(3) non-profit organization dedicated to making every school an ideal place to learn.  

CHPS CriteriaTM: regionally adopted rating system for healthy, high performance schools.  

CHPS DesignedTM: self-certified recognition program for school construction projects that meet the prerequisites and a certain number of credits under a regional version of the CHPS Criteria.  

CHPS PreFABTM: fee-for-service, third party reviewed recognition program for the pre-approval of healthy, high performance prefabricated, modular and relocatable classroom models.  

CHPS VerifiedTM: fee-for-service, third party reviewed recognition program for school construction projects that meet the prerequisites and a certain number of credits under a regional version of the CHPS Criteria.   

CHPS Verified LeaderTM: fee-for-service, third party reviewed recognition program for school construction projects that meet the prerequisites and a certain number of credits under a regional version of the CHPS Criteria.  

Circadian entrainment: The synchronization of the internal body clock with the local solar day through external stimuli. Light is the primary cue for circadian entrainment.  

Circadian Stimulus (CS):  circadian lighting metric that describes acute melatonin suppression and phase shifting of dim light melatonin onset (i.e., the time in the evening when melatonin levels start to rise). CS is modeled from the complete physiological response that includes light intensity, spectra, and duration. The physiological response begins at 0.1 CS and saturation of the circadian system occurs at 0.7 CS. A CS of 0.3 - 0.4 is recommended for circadian entrainment and the alertness response. Peak circadian response occurs at 460 nm. 

Classrooms: See “Core Learning Spaces”  

Core Learning Spaces: Spaces for educational activities where the primary functions are teaching and learning. These spaces include, but are not limited to, classrooms (enclosed or open plan), instructional pods or activity areas, group instruction rooms, conference rooms, libraries, offices, speech clinics, offices used for educational purposes and music rooms for instruction, practice and performance. Also see “Ancillary Learning Spaces”  

Correlated Color Temperature (CCT): A specification of the color appearance of the light emitted by a light source, relating its color to the color of light from a reference source when heated to a particular temperature, measured in degrees Kelvin (K). The CCT rating for a lamp is a general "warmth" or "coolness" measure of its appearance. However, opposite to the temperature scale, lamps with a CCT rating below 3200 K are usually considered "warm" sources, while those with a CCT above 4000 K are usually considered "cool" in appearance. The correlated color temperature (CCT) designation for a light source gives a good indication of the lamp's general appearance, but does not give information on its specific spectral power distribution. Therefore, two lamps may appear to be the same color, but their effects on the circadian system can be quite different. (from RPI). 


Daylight ExcessDaylight Excess is a measure of excessive daylight and reports the fraction of annual hours that exceed a certain illuminance threshold at a given point (typically a workplane point). The maximum acceptable illuminance threshold for spaces with critical visual tasks is considered to be a multiplier of the target illuminance, typically 10x (ie. a 30fc classroom target would use 300fc for Daylight Excess). While potential daylight glare in a space is a function of view angle and the viewed luminance, excessive illuminance can be a good indicator of daylight glare potential, excessive solar heat gains and just excessive daylight in general. Horizontal illuminance calculations can be a good proxy for luminance-based glare potential for a range of viewing angles. Daylight Excess is to be calculated on an annual basis using standard skies calibrated to a representative weather file for the project’s site. Window treatments and the window treatment operation are to be included in any Daylight Excess calculation. 

Daylight SaturationDaylight Saturation is the fraction of the ‘annual lighting load’ that is met with daylight at a given point (typically a workplane point). It defines the maximum lighting savings that could be obtained while ensuring the target illuminance is always met at a given point. The ‘annual lighting load’ for a point is considered to be how much light is required to maintain a target illuminance annually during occupied hours at that given point. It is similar to Daylight Autonomy, but gives ‘partial’ credit to hours where there is partial daylight saturation meeting a portion of the target illuminance in addition to the hours where the target illuminance has been exceeded (100% saturated).  This is an annual daylight metric useful for determining the daylight ‘potential’ of a space, especially relevant for spaces with continuous dimming daylight responsive electric lighting controls. Daylight Saturation is to be calculated on an annual basis using standard skies calibrated to a representative weather file for the project’s site. Window treatments and the window treatment operation are to be included in any Daylight Excess calculation. 

dBA: a measure of the level of sound expressed in units of “decibels”.  The application of the “A-weighted filter” de-emphasizes low-frequency and very high-frequency sound in a manner similar to human hearing.    

Demonstration Areas: A demonstration area identifies a feature of the building where the feature occurs and provides an explanation of the feature and its benefits. 

Direct Sunlight: Illuminance directly from the sun that exceeds 1000fc (100lux). Products that adequately diffuse the direct sunlight (those with a haze factor >98%, or direct transmittance <2%) will typically lower the direct illuminance below this threshold 


Emergency Lighting: Any lighting required for occupants' safety in and around the building. 

ENERGY STAR: A federal government-sponsored program helping businesses and individuals protect the environment through superior energy efficiency.   

EPD: Environmental Product Declaration  

Equivalent Melanopic Lux (EML):  circadian lighting metric that describes the effect of light on melanopsin, a photopigment of the intrinsically photoreceptive retinal ganglion cells (ipRGCs). Peak melanopsin response occurs at 480 nm. 


FAR: Floor Area Ratio, a building’s gross square footage divided by the square footage of the building footprint.  

FEMA: Federal Emergency Management Agency  

Flicker: A change in lighting from modulation of intensity and frequency of lighting conditions. 

  Fully Shielded Light Fixture: A light fixture constructed in such a manner that all light emitted by the fixture,either directly from the lamp or a diffusing element, is projected below the horizontal. Any       structural part of the light fixture providing this shielding must be permanently affixed, and part of the fixture, not part of any surrounding building or architectural elements.


Governing Body:  A public or private school board, board of trustees, or other similar local authority that is in charge of a school, schools, or school district.   


HPD: Health Product Declaration  


Lead-free plumbing standards: Since 2014, plumbing products have to be tested and labeled according to the National Sanitation Foundation (NSF) standards, known as NSF/ANSI 61 and NSF/ANSI 372. On September 1, 2020, the U.S. Environmental Protection Agency (EPA) published the final regulation "Use of Lead-Free Pipes, Fittings, Fixtures, Solder, and Flux for Drinking Water." In the final rule, EPA requires that manufacturers or importers certify that their products meet the requirements using a consistent verification process within 3 years of the final rule publication date in the Federal Register. As a result, this new rule will reduce lead in drinking water and assure that states, manufacturers, inspectors and consumers have a common understanding of “Lead Free” plumbing. 

Light Reflectance Value (LRV): Measures the amount of visible and usable light that reflects from (or absorbs into) a painted surface. The LRV measures the percentage of light a paint color reflects and ranges from 100% for a perfect reflector and 0% for a perfect absorber. Color may have an influence on the LRV, but LRV does not account of for the spectral interaction of colored light and colored materials. For instance, a red, green, and blue surface may all have a LRV of 60%, but the spectral composition of the reflected light will vary significantly. 

Lumen maintenance: The amount of light produced from a light source or from a luminaire when it is brand new to the amount of light output at a specific time in the future.  


MaP: Maximum Performance. A voluntary testing program that measures the effectiveness of toilet flushing in removing waste.  

MAWA: Maximum Applied Water Allowance. For design purposes, the upper limit of annual applied water for the established landscaped area.   

Melatonin: A natural hormone made by your body's pineal gland that promotes sleepiness. Melatonin is a component of the bodies circadian rhythm and often tracked as a circadian system bio-marker. Melatonin increases in concentration as night approaches and environmental light dims. Melatonin concentrations remain high throughout the night, typically peaking in the middle of the night and returning to barely detectable daytime levels by 9am. 

MERV: Minimum Efficiency Reporting Value (MERV) ratings for HVAC system air filters.  ASHRAE standards use the MERV.  The higher rating indicates increased particle capture efficiency and the capture of smaller particles.  


Occupant View/GazeThe amount of circadian resource received by an occupant is highly dependent upon the occupant’s view. For example, an occupant who faces a window may receive x-times the amount of circadian impactful light compared the same location facing away from the window. Similarly, an occupant facing a blue wall will receive x times the amount of circadian impactful light compared the same location but facing a red wall. 


Passive House: There are two Passive House certification bodies in the US, PHI (Passive House Institute) and PHIUS (Passive House Institute US). Both certifications have requirements for airtightness, passive heating/cooling, and energy consumption to ensure the building meets the quantifiable and rigorous level of energy efficiency within a specific quantifiable comfort level. 

Partially Shielded Light Fixture: A light fixture constructed and mounted such that most light emitted by the fixture, either directly from the lamp or a diffusing element, is indirectly by reflection or refraction from any part of the fixture, is projected below the horizontal. Light emitted at or above the horizontal direction (sideways or upwards) arises only from decorative elements or strongly colored or diffusing materials such as "honey" or colored glass or plastic. Fixtures using spot or flood lamps are considered partially shielded if the lamps are aimed at no higher than 45 degrees above straight down (halfway between straight down and straight to the side).


Qualified Simulation SoftwareA daylighting simulation software that can accurately perform the required calculations. Either daylight illuminance calculations on a workplane under standard (CIE or typical clear and cloudy Perez skies) for the 10 times specified or annual Daylight Saturation and Daylight Excess calculations. Commercially available simulation tools for Multiple point-in-time calculations include but not limited to: AGI32, Radiance, SPOT Pro, DAYSIM, DIALux. SPOT Pro, Sefaira, DIVA for Rhino, LightStanza, Open Studio, and Radiance can be used to perform Daylight Saturation and Daylight Excess calculations. 


Regularly Occupied SpacesSpaces with regular occupancy that are primarily devoted to reading and working. These spaces should include at a minimum: classrooms, offices, conference rooms, gymnasium, libraries, and any additional core learning/working areas. Cafeteria and multi-purpose common areas do not need to be included. 

Responsive Design: a term used to encompass design features that create safe and calming spaces, contribute to a sense of community, and allow for students of all abilities, backgrounds, and perspectives to learn together. 

Reverberation time: the time in seconds it takes for the sound level to decrease by 60 decibels after the source of the sound has been abruptly interrupted.  

RoHS: Restriction of Hazardous Substances.  Directive on the use of certain hazardous substances in electrical and electronic equipment, which was originally adopted by the European Union in February 2003.  


Sequence of Operations (SoO): The lighting schedule (often in tabular form), including time of year (if applicable), time of day, correlated color temperature (K), visual illuminance (fc/lux) non-visual illuminance (CS – ML), fade times between scenes or changes of color or intensity, and any additional notes to assist members of the design and construction team in meeting the design intent. The SoO is often a component of a controls narrative,that describes the lighting systems components and functionality in detail. 

Source Energy: The preferred approach for evaluating energy that represents the total amount of fuel that is required to operate a building and incorporates all transmission, delivery, and production losses, thereby enabling a complete assessment of energy efficiency in a building.  

Spectral Power Distribution: From IESNA, “a pictorial representation of the radiant power emitted by a light source at each wavelength or band of wavelengths in the visible region of the electromagnetic spectrum (360 to 770 nanometers).” The spectral make up of a light source can be used to characterize its impact on the circadian system.  

Spectral Reflectance Distributions: Materials selectively reflect light based upon color the properties of that material. A perceived as red reflects predominantly red light, and absorbs other spectra while a predominantly blue material will reflect predominantly blue light. 

STC: Sound Transmission Class, a single-number rating of a material, assembly or partition’s ability to block sound over a range of frequencies consistent with the frequency range of speech. 

Support Spaces: library (media center), cafeteria/dining areas, and commons.


Target Daylight IlluminanceThe target illuminance is assumed to be 30fc for classrooms and administrative spaces (offices, conference rooms) and 50fc for the library, cafeteria, gymnasium, and any multi-purpose common area. A project can use a different daylighting design illuminance provided good documented justification.  


US EPA: United States Environmental Protection Agency  


WELO: California Department of Water Resources Model Water Efficient Landscape Ordinance.  

Wetland: areas that are inundated or saturated by surface or ground water at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Clean Water Act, Section 404. 

WorkplaneAn array of analysis points used for illuminance and direct sunlight calculations. The grid of points shall be located 30” above the floor and have a 3’ x 3’ spacing (or smaller for smaller spaces). The grid should be offset from the exterior walls such that it is no closer than 2’ and no further away than 3.5’. 


zEPI: ZERO ENERGY PERFORMANCE INDEX, A scale representing the ratio of energy performance of the proposed design compared to the average energy performance of buildings relative to a benchmark year of 2000, with similar occupancy, operation schedule and climate. The ratio is multiplied times 100 such that 100 represents a building that uses the same amount of energy as the 2000 average and zero represents a zero net energy building.  

ZEV: Zero Emission Vehicles as defined by the California Air Resources Board.  

ZNE: Zero Net Energy buildings combine energy efficiency and renewable energy generation to consume only as much energy as can be produced onsite through renewable resources over a specified time period. 

ZNE Capable: Zero Net Energy Capable or Zero Net Energy Ready buildings refer to buildings that are as energy efficient as ZNE buildings but don’t have PV onsite. These buildings could access renewable generation from a community-scale project located elsewhere or purchase renewable energy from the local utility.