G-R-E-E-N Spelled Out

If you don’t know exactly what a green home or neighborhood even is, you’re not alone. Think efficient. Think comfortable, healthy, durable. Part of a community. It's a way of living and being in harmony.

To help demystify LEED and green-building, we’ve put together a glossary of green concepts and terms.  We’ve included several resources, with links to sites where you can learn more.

Glossary of terms



Adaptability: Design strategy that allows for multiple future uses in a space as needs evolve and change.

Agricultural Waste: Materials left over from agricultural processes (e.g., wheat stalks, shell hulls, etc.). Some of these materials are finding new applications as building materials and finishes

Adaptive Reuse: Renovation of a building or site to include elements that allow a particular use or uses to occupy a space that originally was intended for a different use.

Air Quality Construction Management Plan: A systematic plan for addressing construction practices that can impact air quality during construction and continuing on to occupation.

Alternative Refueling Station: Location that provides the service of refueling an alternative fuel vehicle (e.g., electricity, compressed natural gas).

ASHRAE: American Society of Heating, Refrigeration and Air Conditioning Engineers. Responsible for national standards such as 90.1, 62.1 & 62.2. More info



Bake-out: Process by which a building is heated in an attempt to accelerate VOC emissions from furniture and materials.

Best Management Practice (BMP): Methods that have been determined to be the most effective, practical means of preventing or reducing pollution from non-point sources.

Bioswale: A technology that uses plants and soil and/or compost to retain and cleanse runoff from a site, roadway, or other source.

Brownfields: Abandoned, idled, or under used industrial and commercial facilities/sites where expansion or redevelopment is complicated by real or perceived environmental contamination. They can be in urban, suburban, or rural areas. EPA's Brownfields initiative helps communities mitigate potential health risks and restore the economic viability of such areas or properties.

Building Cooling Load: The hourly amount of heat that must be removed from a building to maintain indoor comfort (measured in British thermal units [Btu]).



California Multifamily New Homes Program (CMFNH): A program sponsored by PG&E and financed by rate payers that facilitates and encourages energy-efficient design in multifamily housing through design assistance, cash incentives and Energy Star® marketing benefits in the PG&E service territory.

Carbon Footprint: A way to determine an individual or organization’s impact on the environment through the amount of greenhouse gases emitted, which are measured in units of carbon dioxide. Your second home will add to your carbon footprint, but you can take steps in the construction and maintenance to reduce your impact.

Carbon Neutral Design: Refers to a design process that produces no carbon release through any of its stages, and therefore will not contribute to greenhouse gases or global warming.

Cellulose Insulation: Insulation alternative to glass fiber insulation. Cellulose insulation is most often a mixture of waste paper and fire retardant, and has thermal properties often superior to glass fiber.

Certified Lumber: General shorthand term for lumber that has been certified sustainable harvest by an independent certification authority.

Charrette: A meeting held early in the design phase of a project, in which the design team, contractors, end users, community stakeholders, and technical experts are brought together to develop goals, strategies, and ideas for maximizing the environmental performance of the project.

Chicane: An `S` bend in a roadway that reduces speeds by forcing drivers to drive through in a single file. [definition from GreenPlayBook.org]

Cluster Development: Development design that concentrates buildings and infrastructure in specific areas on a site to allow remaining land to be used for recreation, common open space, or the preservation of historical or environmentally sensitive features. [definition from GreenPlayBook.org]

Combined Heat and Power (CHP) or Co-Generation: CHP or co-generation is the simultaneous production of power and usable heat. [definition from GreenPlayBook.org]

Commissioning (Cx) (Building): The process of ensuring installed systems function as specified, performed by a third party Commissioning Authority. Elements to be commissioned are identified, installation is observed, sampling is conducted, test procedures are devised and executed, staff training is verified, and operations and maintenance manuals are reviewed. Typically commenced at completion of construction (often including initial user occupancy) intended to allow designers and managers to check functional subsystems, to determine that the facility is functioning properly, and to undertake any necessary remedial action.

Community: A group of people distinguished by specific common interests and a means of communicating about them. The term embodies social, economic and political relationships among people as well as physical characteristics of their environment. However, community is more about relationships that bind people together than it is about the environment.

Complete Street: A multi-modal street that is designed and operated to enable safe access for all users. Pedestrians, bicyclists, motorists and bus riders of all ages and abilities are able to safely move along and across a complete street. [definition from GreenPlayBook.org]

Conservation Easement: Easement restricting a landowner to land uses that are compatible with long-term conservation and environmental values.

Conservation Subdivision: A form of land regulation that permits flexibility of design in order to promote environmentally sensitive and efficient uses of the land. With land subdivided through a conservation subdivision regulation, local government can preserve unique or sensitive natural resources such as groundwater, floodplains, wetlands, streams, steep slopes, woodlands and wildlife habitat. Conservation subdivisions enable clustering of houses and structures on less environmentally sensitive soils which will reduce the amount of infrastructure (including paved surfaces and utility easements) necessary for residential development. [definition from GreenPlayBook.org]

Construction Waste Management: General term for strategies employed during construction and demolition to reduce the amount of waste and maximize reuse and recycling.

Cost and Benefit Analysis: An economic method for assessing the benefits and costs of achieving alternative health-based standards at given levels of health protection. [definition from GreenPlayBook.org]

Cradle-to-Cradle: A term used in life-cycle analysis to describe a material or product that is recycled into a new product at the end of its defined life.

Cradle-to-Grave: A term used in life-cycle analysis to describe the entire life of a material or product up to the point of disposal. Also refers to a system that handles a product from creation through disposal.

Cost and Benefit Analysis: An economic method for assessing the benefits and costs of achieving alternative health-based standards at given levels of health protection. [definition from GreenPlayBook.org]



Demand Hot Water System: Hot water heaters designed to provide instantaneous hot water, rather than storing preheated hot water in a tank. Such devices can serve an entire home, or be "point-of-use", serving an individual water use. Eliminates energy wasted while keeping stored water warm or when waiting for water to get warm. (Electric demand systems tend to use a large amount of energy; gas-fired units with standing pilot lights lose much of their efficiency due to the ongoing pilot light.)

Displacement Ventilation: Ventilation that uses natural convection processes to move warm air up and out of a volume. Displacement ventilation tends to use less energy than conventional forced air ventilation, as it works with natural convection processes.

Distributed Generation: Distributed generation typically refers to distributed electricity generating technologies (and sometimes heat and power technologies) that are embedded in the local distribution system, either behind the customer meter as in a net metering installation or selling directly into the grid (as in a small independent power producer). [definition from GreenPlayBook.org]

District Energy System: District energy is an approach to supplying thermal energy in the form of steam, hot water and cold water through a distribution system of pipe from a central plant to individual users. Users then extract the energy from the distribution system for their individual heating, cooling and process requirements. [definition from GreenPlayBook.org] Durability Plan & Inspection Checklist: An effective durability management program will consider -- among other things -- the important interrelationships among energy, moisture, and air quality, and how those dynamics are addressed. Other important areas of durability include exterior water strategies, interior moisture control, air infiltration, interstitial condensation, heat loss and radiation control. Green rating programs can serve as guides and produce durability strategies that may be used in the creation of a durability inspection checklist



EIS (Environmental Impact Statement): A document required of federal agencies by the National Environmental Policy Act for major projects or legislative proposals significantly affecting the environment.

Energy Modeling: Process to determine the energy use of a building based on software analysis. Also called building energy simulation.

Energy Star Homes: These homes are at least 5% more energy efficient than homes built to the 2004 International Residential Code (IRC) or CA T•24 Standards, and include additional energy-saving features that typically make them 20–30% more efficient than standard homes. Energy Star homes require third party verification. http://www.energystar.gov/index.cfm?c=new_homes.nh_features

Engineered Lumber/Wood: Composite wood products made from lumber, fiber or veneer, and glue. Engineered wood products can be environmentally preferable to dimensional lumber, as they allow the use of waste wood and small diameter trees to produce structural building materials.

Environmental Footprint: An individual, building or company's environmental impact determined by the amount of depletable raw materials and nonrenewable resources it consumes to make its products, and the quantity of wastes and emissions that are generated in the process.



First Cost: The sum of the initial expenditures involved in capitalizing a property; includes items such as transportation, installation, preparation for service, as well as other related costs. [definition from GreenPlayBook.org]

Fly Ash: A fine, glass-powder recovered from the gases of burning coal during the production of electricity. When mixed with lime and water the fly ash forms a cementitious compound with properties very similar to that of portland cement. Fly ash can be used to replace a portion of cement in the concrete, providing some distinct quality advantages. Substitution of fly ash for portland cement in concrete is considered a sustainable building strategy, as it reduces the amount of energy-intensive (and CO2-producing) cement in the mix, as well as providing performance enhancements.

Flush-Out: A period after finish work and prior to occupation that allows the building’s materials to cure and release volatile compounds and other toxins. A building flush-out procedure is normally followed, with specified time periods, ventilation rate, and other criteria.

Forest Stewardship Council (FSC): A third-party certification organization, evaluating the sustainability of forest products. FSC-certified wood products have met specific criteria in areas such as forest management, labor conditions, and fair trade.



Geothermal/Ground Source Heat Pump: These heat pumps are underground coils that transfer heat from the ground to the inside of a building. (See: heat pump; water source heat pump) This type of heat pump can lead to more substantial energy savings than conventional heat pumps, by using the naturally more stable temperature of the earth as its heat source.

Green Home Guide: A guide for home owners and green residential construction including many useful links. http://www.greenhomeguide.org/index.html

Green Design: A design conforming to environmentally sound principles of site selection & design, building design, selection of appropriate materials, improved indoor environmental quality and reduced materials, water and energy use.

Green Infrastructure: As with Buildings and Neighborhoods, we introduce this section as “Green” Infrastructure. In the context of the Playbook, this implies a broader, sustainable approach with a focus on climate-friendly strategies. However, to avoid confusion with a common use of the term “green Infrastructure” to refer to ecosystem-based services, such as urban forests, the term “sustainable infrastructure” will be used in most cases. [definition from GreenPlayBook.org]

Green Neighborhood: A neighborhood that is typically moderately dense, includes a range of uses, is designed for people and pedestrians first – including a dense network of paths and streets, human-scaled buildings and pedestrian-oriented street design. It has “green” elements, including a network of green spaces and corridors, street trees, significant private landscaping (including possibly green roofs). Buildings are often “green” buildings with excellent environmental performance. Green infrastructure is commonplace, from low-impact stormwater management to district energy systems for example. [definition from GreenPlayBook.org]

Green Play Book: The Playbook provides local governments with guidance and resources to rapidly advance green buildings, neighborhoods and infrastructure. http://www.greenplaybook.org/

Green Power: Energy generated from clean, renewable energy resources such as solar, wind, geothermal, biogas, biomass and low-impact hydro. [definition from GreenPlayBook.org]

Green Roof: Contained green space on, or integrated with, a building roof. Green roofs maintain living plants in a growing medium on top of a pliable layer and drainage system.

Greenwash: Disinformation disseminated by an organization so as to present an environmentally responsible public image.

Greyfield Development: The development of non-contaminated retail areas such as old malls, strip malls, or institutional areas into complete, livable communities. [definition from GreenPlayBook.org]

Gray Water Reuse: A strategy for reducing wastewater outputs from a building, by diverting the gray water into productive uses such as subsurface irrigation, or on-site treatment and use for non-potable functions such as toilet flushing. Gray water reuse is restricted in many jurisdictions; check with local health and building officials.



Halogen: A type of incandescent lamp with higher energy-efficiency that standard ones.

Healthy Building Network (HBN): The Healthy Building Network (HBN) is a national network of green building professionals, environmental and health activists, socially responsible community advocates and others who are interested in promoting healthier building materials as a means of improving public health and preserving the global environment. More info

Heat Island Effect: A "dome" of elevated temperatures over an urban area caused by structural and pavement heat fluxes, and pollutant emissions.

Heat Pump: An electric device with both heating and cooling capabilities. It extracts heat from one medium at a lower (the heat source) temperature and transfers it to another at a higher temperature (the heat sink), thereby cooling the first and warming the second. (See: geothermal, water source heat pump.)

High Reflectance: The ability of materials to effectively reflect the sun's energy. Roof materials with high reflectance stay cooler in the sun, reduce energy costs, improve occupant comfort, and reduce the urban heat island effect. [definition from GreenPlayBook.org]



Indigenous Planting: Landscaping strategy that uses native plants. Provided the natives are placed in the proper growing conditions; such plantings can have low, or zero supplemental water needs.

Indoor Air Quality (IAQ): A measurement of the quality of indoor air based on the amount of pollutants, mold, bacteria, chemicals and allergens present, which all may have adverse effects on the health of residents or occupants of a home or building.

Insulated Concrete Form (ICF): Expanded polystyrene forms that are left in place after the concrete is poured for a foundation or wall. The foam increases the thermal performance of the structure over non-insulated concrete.

Integration: An essential concept in sustainable building. Viewing a building as a system allows the discovery of synergies and potential tradeoffs or pitfalls with design choices. An integrated design approach helps maximize synergies and minimize unintended consequences.

Integrated Design: or Integrative design (process) is a collaborative design methodology emphasizing knowledge integration in the development of a holistic design. The basis for integrated design practices are in the “whole building design” approach. By viewing a building system interdependently as opposed to its separate elements (site, structure, systems and use), this approach facilitates sustainable design practices and can serve to mitigate additional costs that result from ‘greening’ at a later. The integrated design process requires multidisciplinary collaboration, including key stakeholders and design professionals, from conception to completion. Decision making protocols and complimentary design principles must be established early in the process in order to satisfy the goals of multiple stakeholders while achieving the overall project objectives.



Jobs-Housing Balance: A complete, self-sufficient neighborhood requires many buildings housing a variety of daily activities within its boundaries.




LEED™: The Leadership in Energy and Environmental Design (LEED) Green Building Rating System™ is the nationally accepted benchmark for the design, construction, and operation of high performance green buildings.

LEED™ AP (Accredited Professional): LEED Professional Accreditation distinguishes building professionals with the knowledge and skills to successfully steward the LEED certification process. LEED Accredited Professionals (LEED APs) have demonstrated a thorough understanding of green building practices and principles and the LEED Rating System.

LEED™ Certification: Developed by the United States Green Building Council, LEED is the nationally accepted benchmark for the design, building and operation of green buildings. There is a LEED certification system for homes; visit www.greenhomeguide.org for more information.

Life Cycle Analysis (LCA): The assessment of a product's full environmental costs, from raw material to final disposal, in terms of consumption of resources, energy and waste. Life cycle analysis is used as a tool for evaluating the relative performance of building materials, technologies, and systems.

Light-Emitting Diode (LED): A long-lasting illumination technology used for exit signs which requires very little power.

Low Emissivity (low-E) Windows: Window technology that lowers the amount of energy loss through windows by inhibiting the transmission of radiant heat while still allowing sufficient light to pass through.

Low-Impact Development: A comprehensive land planning and engineering design approach with a goal of maintaining and enhancing the pre-development hydrologic regime of urban and developing watersheds. This design approach incorporates strategic planning with micro-management techniques to reach the greatest environmental protection, while allowing for development or infrastructure rehabilitation to occur. [definition from GreenPlayBook.org]



Maintenance: An overlooked element of a product, system, or design strategy that impacts cost over the life cycle. Selecting products and designing for easy maintenance enhances durability and lessens the likelihood that maintenance is overlooked. Establishing and adhering to a maintenance protocol ensures that materials and systems meet specifications. Modular Building: Building technique using modular or pre-constructed components. Building on a "module" also refers to the concept of using standardized dimensions that reduce the amount of construction waste. Building in four-foot increments is one strategy.



National Center for Healthy Housing: NCHH sponsors research on methods to reduce residential environmental hazards and to scientifically assess risks.

Neighborhood: An urban area having a diverse range of building types, thoroughfares and public open spaces accommodating a variety of human activity.

New Urbanism: New Urbanism is an approach to designing cities, towns, and neighborhoods that tries to reduce traffic and eliminate sprawl. Although the term New Urbanism emerged during the late 1980s and early 1990s, its principles are actually quite old.



On-Site Stormwater Management: Building and landscape strategies to control and limit stormwater pollution and runoff. Usually an integrated package of strategies, elements can include vegetated roofs, compost-amended soils, pervious paving, tree planting, drainage swales, and more.

Open Space Preservation: The protection of natural areas both within and around communities that provide important community space, habitat for plants and animals, recreational opportunities, farm and ranch land (working lands), places of natural beauty and critical environmental areas (e.g. wetlands). [definition from GreenPlayBook.org]

OSB: Oriented Strand Board. A high strength, structural wood panel formed by binding wood strands with resin in opposite directions. OSB is environmentally beneficial because it uses small-sized and waste wood for its fiber; however, resin type should be considered for its impact on human, and the production process monitored for air pollutant emissions.

Overhangs: Architectural elements on roofs and above windows that are used to protect the structure from the elements or to assist in day lighting and control of unwanted solar gain. Sizing of overhangs should consider their purpose, especially related to solar control.



Passive Solar: Strategies for using the sun’s energy to heat (or cool) a space, mass, or liquid. Passive solar strategies use no pumps or controls to function. A window, oriented for solar gain, coupled with massing for thermal storage (e.g., a Trombe wall) is an example of a passive solar technique.

Pharos Project: Pharos Project focuses on making building material evaluations as comprehensive as possible – encompassing health, sustainability and social justice issues throughout the life cycle. http://www.pharosproject.net/

Photocell: A device that measures the amount of incident light present in a space.

Photovoltaic (PV) Cell: An electronic device consisting of layers of semiconductor materials capable of converting incident light directly into electricity (direct current). PV cells are used in solar panels.

Photovoltaic (PV) Module: A collection of interconnected photovoltaic cells designed to deliver a selected level of working voltage and current at its output terminals. PV modules are packaged to protect them against environmental degradation and suited for use in photovoltaic power systems.

Porous Paving: Paving surfaces designed to allow stormwater infiltration and reduce runoff.

Public Benefits Charge: A charge added to a customer billing which is intended to cover costs related to services that a utility provides in the public interest. A utility may be legally required to provide some or all of the services covered by this charge; these services range from educational initiatives to funding for low-income customers to environmental programs. [definition from GreenPlayBook.org]

Public Transportation: Mass transit, including bus and light rail systems. Placing a building near public transit is considered a sustainable building strategy as it makes it easier to commute without using a car.




Radiant Heat: Heat transferred in the form of light energy (including non-visible spectra). Unlike conductive heat it occurs with the direct contact between two materials.

Rainwater Harvest: On-site rainwater harvest and storage systems used to offset potable water needs for a building and/or landscape. [definition from GreenPlayBook.org]

Reclaimed Materials: Building materials taken from old structures that are being reused or refinished in new buildings. This can include reclaimed lumber, flooring, tiles, beams and more.

Regenerative Design: A system with absolute efficiency used for sustainable development. The concept behind this system is one in which all waste products of one system can be used in the same or in different systems with zero loss of input and output. The system thus sustains itself.

Regreen: A web-based resource consisting of best practice guidelines and targeted educational resources for sustainable residential remodeling projects http://www.regreenprogram.org/

Renewable Energy: Sources of energy that are replenished naturally, such as sunlight and wind. Examples include solar power, wind power and hydroelectricity.

Renewable Resources: A resource that can be replenished at a rate equal to or greater than its rate of depletion; e.g., solar, wind, geothermal and biomass resources.

Road Diet: A technique of transportation planning in which the width of a road or lane is narrowed in order to achieve improvements to the transportation system. A typical road diet technique is to reduce the number of lanes on a roadway cross-section. The additional space that is freed up by removing a vehicular lane can be converted into two bike lanes on either side of the roadway. [definition from GreenPlayBook.org]



Shared Street: A common space created to be shared by pedestrians, bicyclists, and low-speed motor vehicles. They are typically narrow streets without curbs and sidewalks, and vehicles are slowed by placing trees, planters, parking areas, and other obstacles in the street. [definition from GreenPlayBook.org]

Sisal: A durable natural fiber used as a floor covering, made from leaves of the sisal plant.

Slag: a byproduct of smelting ores. Similar to flyash, ground granulated slag is often used in concrete in combination with Portland cement as part of a blended cement.

Smart Growth: A collection of urban development strategies meant to reduce sprawl that are fiscally, environmentally and socially responsible. Smart Growth is development that enhances our quality of life, protects our environment, and uses tax revenues wisely. [definition from GreenPlayBook.org]

Stormwater Management: Building and landscape strategies to control and limit stormwater pollution and runoff. Usually an integrated package of strategies, including elements like vegetated roofs, compost-amended soils, pervious paving, tree planting, drainage swales, and more. [definition from GreenPlayBook.org]

Sustainable Design: The art of designing physical objects and the built environment to comply with the principles of economic, social, and ecological sustainability. From wikipedia.

Sustainable Development: A socio-ecological process characterized by the fulfillment of human needs while maintaining the quality of the natural environment indefinitely.



Title 24 (T•24): The Energy Efficiency Standards for Residential and Nonresidential Buildings were established in 1978 in response to laws requiring a decrease in California's energy consumption. More info

Traditional Neighborhood Development (TND): Development that is based on human-scale design for comfortable walking and may include such elements as: alleys, streets laid out in a grid system, buildings oriented to the street, front porches on houses, pedestrian-orientation, compatible and mixed land uses, village squares and greens. [definition from GreenPlayBook.org]

Transit-Oriented Development (TOD): Moderate and high-density housing concentrated in mixed-use developments located along transit routes. The location, design and mix of uses in a TOD emphasize pedestrian-oriented environments and encourage the use of public transportation. [definition from GreenPlayBook.org]

Triple-Bottom Line (TBL): Measuring the economic, social and environmental performance of a project. This method of assessment aims for synergy amongst these three aspects rather than compromise or ‘trade-offs’ between them. Also referred to as P3 or E3.



Unbundled Parking: A parking strategy in which parking spaces are rented or sold separately, rather than automatically included with the rent or purchase price of a residential or commercial unit. Tenants or owners are able to purchase only as much parking as they need, and are given the opportunity to save money and space by using fewer parking stalls. Unbundled parking is more equitable and can reduce the total amount of parking required for the building. [definition from GreenPlayBook.org]

Universal Accessibility: Access to environments and products that is, to the greatest extent possible, usable by everyone regardless of their age, ability, or circumstance. [definition from GreenPlayBook.org]




Walking Distance: A distance comfortable for most people to walk, as an attractive alternative to driving. This distance is best represented as one quarter mile, 1,320 feet, or a five-minute walk.

Water & Wastewater Infrastructure: The network of pipes, systems and facilities that provide fresh water supply and wastewater (sewage) management for communities. [definition from GreenPlayBook.org]

WaterSense: WaterSense labeled products are analogous to Energy Star labeled products and will perform well, help save money, and use less water. More info

Water-Source Heat Pump: Heat pump that uses wells or heat exchangers to transfer heat from water to the inside of a building. Most such units use ground water. See Groundsource and Heat pump.

Wind Turbine: Device for generating electricity from wind; windmill.





Zero Energy Design: Describes buildings and products that have no net energy consumption in a given year.