Glossary of Passive Home Building Terms

Building a home is difficult enough, let alone the terms used throughout the process. To help, we’ve created a brief glossary of sustainable home building and design terms. For those who are considering a new home, this glossary is a convenient, easily accessible resource to help expand your knowledge (and vocabulary)!

 

Air barrier: Building assembly components that work as a system to restrict air flow through the building envelope.

Blower-door test: Test used to determine a home’s airtightness. A powerful fan is mounted in an exterior door opening and used to pressurize or depressurize the house.

Building envelope: Encompasses the entire exterior of a home, from the foundation and windows and doors, to insulation and the roof. A vital step in making a home energy efficient is reducing uncontrolled air leakage in the home envelope.

Carbon Footprint: The impact a particular activity has on the environment in terms of the amount of climate-changing carbon dioxide and other greenhouse gases it produces.

Design-Build firm: Company that handles both house design and construction.

Embodied energy: Energy that goes into making a product; includes energy required for growth, extraction, and transportation of the raw material, as well as manufacturing, packaging, and transportation of the finished product.

Energy Star: Labeling system sponsored by the Environmental Protection Agency and the US Department of Energy for labeling the most energy-efficient products on the market. Applies to a wide range of products, from computers and office equipment to refrigerators and air conditioners.

Formaldehyde: A noxious gas used to manufacture many building materials and household products, including adhesives in engineered wood and in the processing of wrinkle-resistant fabrics.

HVAC: Heating, ventilating, and air conditioning. Collectively, the mechanical systems that heat, ventilate, and cool a building.

Heating load: Rate at which heat must be added to a space to maintain a desired temperature.

Heat recovery ventilator (HRV): Balanced ventilation system in which most of the heat from outgoing exhaust air is transferred to incoming fresh air via an air-to-air heat exchanger; a similar device, an energy-recovery ventilator, also transfers water vapor.

LEED: Leaders in Energy and Environmental Design is a building environmental certification program developed and operated by the US Green Building Council.

Low-E (Low-Emissive): Coating applied to glass that allows light through but reflects heat, helping control seasonal interior temperature fluctuations due to solar loss and gain.

MSDS (material data safety sheet): Provides information for workers and safety personnel about potentially hazardous substances.

Net-zero energy: Producing as much energy on an annual basis as one consumes on site, usually with renewable energy sources such as photovoltaics or small-scale wind turbines.

Orientation (solar): Orientation of a structure for controlled solar gain is essential to the success of passive and active solar design elements.

Passive design: Considering the thermal processes of convection, conduction, absorption, and radiation in a design to maintain comfort levels and reduce or eliminate the need for mechanical systems for these purposes.

Passive heating: Channeling the heat of the sun into natural thermal processes like radiation, conduction, and convection to heat a structure instead of relying on a mechanical heating system.

Passivhaus standard: A residential building construction standard requiring very low levels of air leakage, very high levels of insulation, and windows with a very low U-factor.

Photovoltaic: Generation of electricity from the energy of sunlight, using photocells.

Renewable energy technologies: Active, passive, and photovoltaic strategies integrated into building design.

R-Value: Short for “resistance to heat flow.” Measurement of the thermal resistance of a material, frequently referenced as a measurement for insulation. Increasing the R-value of insulation implies better thermal performance and energy efficiency.

Solar gain: Increase in temperature contributed to a space by the sun’s rays.

SIP (Structural Insulated Panel): Considered both a composite and modular system, SIPs are prefabricated systems used primarily for walls and roofs that achieve high insulation values.

Tankless water heater: An energy efficient water heater that heats water on demand (rather than traditional heaters, which expend a lot of energy continually heating stored water in a tank).

Thermal bridging: Unwanted heat loss or gain due to conduction through a material. An example of thermal bridging is heat loss that occurs with structural steel framing that is insufficiently insulated between conditioned and unconditioned space.

Thermal mass: Heavy, high-heat-capacity material that can absorb and store a significant amount of heat; used in passive solar heating to keep the house warm at night.

U-Factor: The rate of heat loss is indicated in terms of the U-factor (U-value) of a window assembly. The lower the U-value, the greater a window’s resistance to heat flow and the better its insulating value.

VOC (Volatile Organic Compound): Carbon compounds that vaporize at room temperature, and often contribute to poor air quality in a space. Off-gassing is the release of volatile, toxic chemicals by products after installation.

Xeriscaping: Type of landscaping that requires little if any irrigation; suited to dry and drought-prone climates; generally relies on regionally adapted native plants.

Want to learn more about Clarum Homes and additional home building terms? Call us at 650.322.7069.