glossary

terms used on the site

Air Barrier: Materials or systems that prevent air from leaking through the building envelope. 

Air Filtration System (HEPA): A high-efficiency air filter capable of removing particles as small as 0.3 microns, including dust, pollen, mold, bacteria, and some smoke and pollutants. HEPA filters purify air by pushing it through a fine mesh.

Air Seals: Barriers that block the unintended flow of air to or from the outdoors.

Air Source Heat Pump: A heat pump that transfers heat from the outdoor air into the building during winter and releases heat outside during summer, using a refrigerant.

Bidirectional Charging: Technology that enables electric vehicles to both supply and receive energy allowing electricity to flow both ways.

Blower Door Test: A diagnostic test that measures a building’s airtightness, which assists in locating potential leaks in the building envelope.

Building Envelope: The physical barrier between the conditioned and unconditioned environment, intended to support climate control and protect against external elements such as water, heat, light, and noise. External elements include foundations, walls, roofs, floors, windows, doors, insulation, air seals, and vents.

Carbon Emissions: Greenhouse gas emissions like carbon dioxide, methane, and nitrous oxide that are the result of human activity and contribute to climate change. Human emissions are created from burning fossil fuels for energy, industrial processes, transportation, and agriculture.

Carbon Footprint: The total amount of greenhouse gas emitted by a person, product, activity, or group over its lifetime. 

Carbon Pre-Filters: Carbon-coated filters that trap particles and remove odors are often used in front of HEPA filters to trap larger particles, which can extend the filter’s life.

Controlled Mechanical Ventilation: A system used to improve indoor air quality by filtering and exchanging outdoor air into the building’s living areas.

Continuous Insulation: Insulating material across a structure without breaks or thermal bridges beyond fasteners and service openings.  

Cold Roof: Roofs with space between the roof covering and insulation, allowing for ventilation. The ventilation creates continuous airflow, which prevents ice dams, minimizes heat loss, and prevents uneven snow melt by keeping the roof cool.

Daylighting: Using controlled natural light through windows and other openings to illuminate the inside of a house for reduced electric lighting and improved energy efficiency.

Defensible Space: The critical area between a structure and an oncoming wildfire that can be used to impede property ignition and allow firefighters to defend the home. Combustible materials should be cleared, and landscaping should follow the zone guidelines that set forth the best way to manage vegetation to minimize fire risk.

Direct Combustion: The process of burning biomass in open air to generate electricity in steam turbines to heat water and buildings.

Electrified HVAC System: HVAC systems that are powered by electricity instead of gas.

Embodied Carbon: Carbon emissions released over the entire lifecycle of a product: production, transportation, installation, maintenance, and disposal of building materials.

Energy Audit: An assessment of a building’s energy use that identifies points of energy loss and home improvements for improved energy efficiency. During an energy audit, an inspector will analyze the building envelope, HVAC system, lighting, appliance and equipment, and your utility bill. They will then provide you with a detailed report of their results and recommendations.

 

Energy Star: A certification given by the U.S. Environmental Protection Agency and the U.S. Department of Energy, awarded to a product, building, or home for meeting energy efficient standards. 

EV Charging: Transferring electricity from a power source into a battery-powered vehicle via a plugin.

Fire-Resistant Materials: Materials with properties that are designed to withstand high temperatures and ignition.

Geothermal Energy: A renewable energy source that uses the consistent temperature of the Earth to heat and cool buildings. They are installed as either a closed-loop or open-loop system that extracts heat from the ground and into the building during the winter, draws heat from the air, and transfers it into the ground during the summer. 

Heat Pump: A device that uses electricity to move heat from one place to another. A refrigerant changes from gas to liquid and vice versa to move heat from outside to inside in the winter and from inside to outside in the summer.

Heat Recovery Ventilators (HRV): Mechanical ventilation systems that improve indoor air quality by exchanging stale indoor air for fresh air through two separate air streams while preventing energy loss.

High-Performance Home: A property that is built with a sustainable design to be more energy-efficient, comfortable, and durable than traditional homes. Features of high-performance homes include an air-tight building envelope, efficient temperature regulation systems, sustainable materials with high thermal mass, and smart technologies to manage air quality and energy consumption.

Home Battery: A large battery that stores energy for later use. Home batteries can be charged via renewable sources or by the grid.

Home Hardening: The process of modifying a structure and landscape to be fire-resistant. This includes using non-combustible building materials, managing vegetation, sealing gaps, removing flammable materials from the property, maintaining ventilation systems that block embers, and creating defensible space to protect a home from flames from oncoming wildfires.

Hardscaping: Using non-living elements in a landscape to create structures such as stone walls, concrete patios, decks, and walkways that are both aesthetic and fire resistant.

HVAC: Heating, Ventilation, and Air Conditioning systems. They artificially regulate temperature and humidity in buildings. 

Induction Cooktops: A cooktop that uses electromagnetic energy to heat only the cookware without changing the temperature of the surface. 

Native Landscaping: A landscaping method incorporating predominantly native plants to create a low-maintenance, fire-resistant, waterwise landscape that supports the local ecosystem and uses minimal fertilizer.

Occupant Comfort: A measure of how well a building can provide a satisfying, efficient, and healthy living environment for those who live there.

Outdoor Heating: Using electric gas sources to heat outdoor products, appliances and spaces. These devices emit heat using infrared or radiant heat to warm nearby areas. Since these devices are outside, the heat is quickly lost, making them highly inefficient.

Passive Home Design: A building design concept that meets a high standard of energy efficiency and comfortability and uses sustainable materials to minimize heat loss and the need for unnatural heating and cooling.

Powder Watts: A smart technology system designed to detect winter roof conditions that may cause damage to the roof.

R-Factor, R-Value: A unit of measurement that indicates a material’s thermal resistance and insulation properties. Higher R-values equate to a building’s high energy efficiency. R-values of 0.20 or less are considered reliable.

Roof Heat Tape: A cable or cord heater used on the roof to melt snow and prevent ice dam formation.

Seismic Activity: Vibrations or movements in the Earth’s crust. This can also refer to specific measurements such as frequency, type, and size of an Earthquake at a particular time.

Solar Energy Systems: Renewable energy systems that use the sun’s energy to generate usable electricity or heat. 

Solar Gain: The amount of solar energy absorbed and retained in a space, object, or structure, resulting in a natural increase in temperature. In colder climates, south-facing homes can capture additional free heat from the sun when adjacent buildings and topography don’t overshadow them.

Solar-Powered Backup System: Solar panels and batteries that provide electricity during electric outages and low sunlight. This can include

Solar PV: A renewable energy system that converts solar energy into energy by absorbing sunlight through photovoltaic cells. 

Solar Thermal: A renewable energy source that uses solar energy to create heat or electricity. Solar thermal systems use the sun’s energy to heat a fluid that provides heat to the building.

Spray Foam: A type of plastic insulation sprayed onto a surface to insulate and seal a building. This material is made of isocyanate and polyol resin that expands to fill cracks. 

Surface-To-Volume Area: This measurement can be calculated by dividing the surface area of an object by its volume, indicating the amount of surface area per unit of volume within a structure. Energy efficient homes typically have a low surface-to-volume ratio because the low surface area compared to the volume reduces the amount of heat lost or gained through the building's exterior elements.

Sustainable Materials: Building materials obtained from renewable sources that provide ecological benefits and have a reduced environmental impact over the course of their lifecycle. They tend to be durable and have improved insulation properties when compared to conventional materials.

Tankless Electric Water Heaters: Also known as instant water heaters, they heat water through an electric or gas burner without using a storage tank. Because these heaters don’t need to keep large amounts of water warm, they are often more energy efficient.

Thermal Bridging: Weak points in a building’s envelope that allow heat to transfer into a material with a higher thermal conductivity, resulting in heat lost to surrounding materials. For example, concrete walls conduct more heat than the insulation around them. If a thermal bridge occurs, heat will transfer from the insulation to the concrete wall and be lost to the home’s exterior.

Thermal Conductivity: A materials ability to conduct heat. Thermal conductivity is measured by the speed at which heat is transferred through the material. High rate = higher thermal conductivity.

Thermal Mass: A material's ability to store, absorb, and release heat. Materials with a high thermal mass naturally regulate temperature, absorbing heat during the day and slowly releasing it at night to maintain a comfortable temperature without artificial heating and cooling. Concrete and brick, for example, have a high thermal mass, while materials like timber and cloth do not retain heat as well and lose thermal energy easily.

Vapor Barrier: A material that prevents water vapor from entering a building through exterior and foundational elements such as walls, floors, ceilings, or roofs. Vapor barriers prevent water from condensing within the building structure, which can result in mold and damage to wooden structures.

Volatile Organic Compounds: Chemicals that vaporize at room temperature (solids or liquids). They are found in many products or materials and lead to air pollution and can cause long term health damage.

Water Heating: Using an energy source to increase the water’s temperature from its initial value.