green glossary

Advanced Framing:  A structural system designed using conventional wood framing while reducing the total volume of lumber used.  The principal components of an advanced framing system typically include use of two-foot on-center wall, floor and roof framing; and laying out the building according to a two-foot building module, ideally with window size and placement coordinated with the module.  Because less lumber per square foot is used, higher insulating values can be achieved.  Also called “Optimum Value Engineering” or “OVE.”

Building Integrated Photovoltaic (BIPV):  The architectural, structural and aesthetic integration into the building envelope of thin-film photovoltaic materials that convert sunlight into electricity.  BIPVs are used in place of roof-mounted “solar panels” or free-standing photovoltaic arrays.  BIPVs can be made opaque or partially transparent and therefore can be used in such diverse applications as window wall systems, skylights, sunshades, or roofing material.  Some BIPV installations are not as efficient as standalone PV arrays and so proper design is critical.

Built Green™:  A nonprofit, residential building program in the greater Seattle area which provides consumers and builders with a rating system for environmentally-friendly building.  Awarded by the Master Builders Association (MBA) of King County the program offers 1-, 2-, and 3-Star levels that are self-certifying, and 4- and 5-Star levels that require third-party verification. Features included in the Built Green checklist towards certification include:

  • Green Codes - Meeting energy, air quality, water efficiency, and storm water-management standards.
  • Site & Water Protection – Site and water protection in development techniques.
  • Energy Efficiency – Pushing your project beyond the energy code.
  • Health and Air Quality – Promoting good air quality, before, during, and after construction.
  • Materials Efficiency – Reducing job-site waste.
  • Environmentally Responsible Home Ownership – Integrating homeowner education.

Cool Roof:  Roofing designed to reflect the sun’s heat and emit absorbed radiation back into the atmosphere rather than transmitting it to the building below.  The two basic characteristics that determine the ‘coolness’ of a roof are solar reflectance (SR) and thermal emittance (TE).  Both properties are rated on a scale from 0 to 1, where 1 is the most reflective or emissive.

Compact Fluorescent:  Commonly refers to high-efficiency light bulbs made with fluorescent bulbs that are designed to replace standard bulbs without modifying the original light fixture.  Complete fixtures utilizing compact florescent technology are also available that mimic the appearance of standard light fixtures such as recessed “can” lights.

Compost Soil Add Mix:  Healthy soils amended with compost absorb and hold water better than un-amended soils, decreasing the need for landscape irrigation.

Deconstruction:  The systematic disassembly and recycling/reuse of materials from an existing structure in order to divert those materials from landfills. Deconstruction is considered a more sustainable alternative to demolition.

Dual Flush Toilets:  High water-efficiency toilets with two flush mechanisms: a low flow flush for liquid wastes and a higher flow flush for solid wastes.  Because much less water is required for the low flow flush, dual flushed toilets save water while maintaining adequate performance.

ENERGY STAR®:  International standard for qualifying consumer products that meet strict energy-efficiency guidelines set by the Environmental Protection Agency (EPA) and United States Department of Energy.  Initiated as a voluntary labeling program designed to identify and promote energy-efficient products, the ENERGY STAR logo appears on a wide range of items including major appliances, office equipment, lighting, home electronics and more.  The program saved enough energy in 2007 alone to avoid greenhouse gas emissions equivalent to those from 27 million cars while saving Americans $16 billion on their utility bills. ENERGY STAR is a registered trademark of the United States Environmental Protection Agency.

ENERGY STAR® Home:  Meets guidelines for energy efficiency established by the EPA.  ENERGY STAR qualified homes include energy-saving features and are at least 15% more energy efficient than required by the 2004 International Residential Code.  Typical features of an ENERGY STAR Home include:  an efficient building envelope, efficient air distribution, efficient equipment for heating, cooling and hot water, efficient lighting fixtures, and efficient appliances.

ENERGY STAR® Home Environments For Living:  To qualify for Environments for Living certification, a home must meet the requirements of the ENERGY STAR Home program plus additional indoor air quality criteria such as moisture management, HVAC requirements, filtered fresh air ventilation, and CO detectors.

EPA (Environmental Protection Agency):  Works to develop and enforce environmental laws enacted by Congress.  The EPA is responsible for setting national standards for environmental programs with the goal of protecting human health and the environment.

Forest Stewardship Council (FSC®) Certified:  identifies wood products that are produced from forests meeting specific environmental and social standards.  When a forest is FSC certified, the wood products which originate from certified forests receive a “chain of custody” certification that allows the products to be traced back to and identified as having come from an FSC-certified forest.  FSC is a trademark of the Forest Stewardship Council.

Geothermal Heat Pump:  From the Greek words for “earth heat,” geothermal systems use inherently stable below-ground soil or water temperatures to heat buildings in the winter and cool them in the summer.  Because soil temperatures remain a nearly constant 50-60 degrees Fahrenheit, they are usually warmer than the air in winter and cooler than the air in summer.  Geothermal heat pumps transfer heat from the ground (or water) into buildings in winter and reverse the process to cool buildings in the summer.  The shortened term “geothermal” is often used when referring to geothermal heat pumps but other geothermal technologies extract heat from hot springs, volcanic activity, etc.

Gravity-Film Heat Exchange (GFX):  An enhanced plumbing system used to capture heat from drain wastewater and pre-heat water entering the hot water supply.  Typically utilizing a copper heat exchange coil, GFX is most effective where wastewater is created at the same time hot water is needed, as in showers.

Gray Water Recycling:  The capture and on-site reuse of domestic wastewater from sinks, laundry, showers and baths.  Recycled gray water is typically used for irrigation and/or non-potable household functions such as toilet flushing or clothes washing.  If gray water is recycled for household use, a parallel plumbing system is employed to separate the gray water from potable water sources.  Gray water reuse reduces the total wastewater output by diverting the gray water to productive, non-potable uses.  Gray water does not include water or wastes from toilets, kitchen food grinders or dishwashers, which is considered “blackwater.”

Heat Recovery Ventilator:  A mechanical fan system that exhausts stale air from a building but transfers the heat of the outgoing air to fresh incoming air.  A type of “heat exchanger,” a heat recovery ventilator reduces the costs of heating ventilated air.

HEPA Filter (High Efficiency Particulate Air):  Used to filter air in mechanical systems and must remove at least 99.97 percent of airborne particles to be designated as HEPA.  HEPA filters are designed to target very small pollutants and particles including pollen and dust mites.  The popularity of HEPA filter vacuums with allergy and asthma sufferers has resulted in an increase in the number of manufacturers and models that are available.

Insulated Concrete Formwork (ICF):  Stay-in-place rigid foam forms filled with concrete to create for energy-efficient, structural concrete walls.  The forms are interlocking modular units that are dry-stacked (without mortar), filled with concrete, and braced.  ICF walls have excellent insulating and acoustical properties and are resistant to mold.

Issaquah Highlands:  Issaquah Highlands is one of the largest green building developments in Washington State and the first Pacific Northwest community to receive a Built Green Community designation.  All homes in the Harrison Street and Grand Ridge Drive developments are required to have Built Green four-star certification.

LEED® (Leadership in Energy and Environmental Design):  A national certification program for the design, construction and operation of high performance green buildings.  LEED has several rating systems tailored for different building types, but all are based on a set of credits in five categories: sustainable site development, water savings, energy efficiency, materials selection, and indoor environmental quality.  In residential design, LEED for Homes uses a point system based on the average-size home.  LEED is a registered trademark of the United States Green Building Council.

Low Flow Showerheads:  Water saving shower head typically rated at 2.5 gallons per minute (gpm) or less.  There are two types of low flow shower heads.  The most common is the aerating shower head which mixes air with the water.  The other is a non-aerating shower head which simply restricts the volume of water.

Mold Resistant Drywall:  A gypsum based wall board that is treated with mold resistant chemicals or has non-paper facings to reduce the risk of mold growth.  Untreated, paper faced wall board can allow mold to grow on the cellulose that the paper contains.  .

Native Plants:  Plant species that evolved naturally in a region and were not introduced by human contact.  Sustainable landscape design encourages the use of native plants because they generally require less irrigation than non-natives, attract native animals (particularly pollinating and seed-dispersing insects and birds), and repel or survive native insects and diseases.  In contrast, non-native plants often require more intensive watering and can become invasive if they spread aggressively.  

OSHA (Occupational Safety and Health Administration):  Issues and enforces standards for workplace safety and health in order to prevent work–related injuries.

Pervious Concrete:  Concrete containing little or no sand and with substantial void content to allow water to filter quickly through the concrete.  Typically used for exterior paving, pervious concrete can help reduce the detrimental effects of runoff by allowing rainwater to penetrate the soil in a more natural fashion due to its low mortar content and high porosity, pervious concrete has a lower strength than conventional concrete mixtures.

Pervious Pavers:  A generic term for modular blocks or grid pavement systems designed to allow rainwater to collect in a substrate and slowly filter into the ground.  Because pervious pavement systems reduce storm water run-off and the associated risks of flooding and introduction of surface pollutants into the streams and lakes, pervious pavers are considered a more sustainable alternative to impervious pavement.

Photovoltaic Panels:  Solar panels used to directly convert the sun’s energy into electricity.  Photovoltaic panels may be installed on rooftops or as free-standing arrays.

Radiant Floor Heating:  Radiant floor heating systems heat a building by directly heating the floor structure; usually by hot water piping or electrical wires which are in direct contact with the floor.  Radiant floor heating is usually more efficient than conventional forced-air heating because no energy is lost through ducts.  As conventional forced-air often introduces outside allergens and other pollutants to the indoor environment, a building with radiant floor heating will have better indoor air quality.  The most common and energy-efficient radiant floor heating systems are hydronic (liquid-based) systems in which heated water is pumped through tubing laid in a pattern underneath or embedded into the floor.  Hydronic systems can be heated with standard boilers, wood-fired boilers, solar water heaters, or a combination of heat sources.

Rain Screen:  A method of installing an exterior finish so that water can properly drain away from the building structure even if the water has penetrated the exterior finish.  Rain screen systems are designed to prevent water intrusion from incidental exposure, (rain, splashing, etc), capillary action and air pressure.  The primary feature of the rain screen installation is a vented air space between the exterior finish material and the building structure.  Most water (incidental) is shed by the exterior finish material.  The air space breaks the capillary action across materials that are in close contact and the air space can act as a pressure equalizer preventing air or wind pressure from driving water into the building structure.  A secondary waterproofing layer on the building structure sheds any remaining water.  Rain screen systems help buildings “breath” better and help prevent standing water which can lead to mold problems.

Rainwater Harvesting:  The on-site capture, storage and use of rainwater.  Harvested rainwater may be stored in cisterns, tanks or rain barrels for non-potable domestic use, irrigation, or water features where a high level of water purity is not required.  Harvested rainwater is easily contaminated, and can not be used for drinking, cooking, or bathing. 

Recycled Concrete:  A concrete mixture with a portion of industrial waste byproducts such as fly ash (from coal combustion) or blast furnace slag (created in iron manufacture) used in place of typical Portland cement.  Use of these “supplemental cementitious materials” prevents the waste materials from entering landfills, and minimizes the amount of cement needed and can increase the strength and durability of the concrete.  Because cement manufacture is extremely energy-intensive, cement substitutes dramatically reduce the amount of embodied energy in concrete.  Demolished concrete structures can also be “recycled” by crushing the concrete for re-use in new concrete, fill material, or base material for roads, sidewalks and slabs.

Structural Insulated Panels (SIPs):  Factory-made, energy-efficient building panels typically constructed of an insulating core of rigid foam sandwiched between two structural panels of oriented strand board (OSB).  SIPs can be used in floors, walls or roofs of residential and light commercial buildings in place of conventional light-frame wood construction techniques.  SIPs can achieve greater insulation values than conventional framed wood walls.

Volatile Organic Compounds (VOCs):  Used in the production of many common products such as paint and household cleaners.  Products with VOCs often emit the VOCs as a gas (off-gassing) and pollute indoor air.  Low or no VOC paints release minimal or no VOC pollutants and are virtually odor-free, improve indoor air quality and are critical for individuals who are sensitive to chemicals.  Paints with high levels of VOC also require toxic solvents when cleaning up that release even more VOC pollutants.  Low VOC paints are tested by OSHA and the EPA for toxicity, coverage, fire resistance and durability in the same manner as conventional paints.  Some latex-based, low VOC paints use water as their solvent and carrier so their clean-up solutions consist of soap and water.

WaterSense®:  A partnership program sponsored by EPA, to promote water-efficiency and water-efficient products, programs and practices by identifying and labeling products that meet the EPA’s water-efficiency and performance criteria.  WaterSense is a registered trademark of the United States Environmental Protection Agency.

Zero Energy Buildings (ZEB):  Highly energy-efficient buildings that produce energy using photovoltaics, wind turbines or other microgeneration technologies sufficient to fully offset any power purchased from public utilities on an annual basis.  To cope with fluctuations in demand, zero energy buildings draw energy from the power utility when insufficient electricity is produced for current needs and export electricity to the grid when energy is produced in surplus.