Active solar system: A solar energy system that uses mechanical components (pumps, fans, or tracking mechanisms) to collect and distribute solar energy. Contrasted with passive solar systems.
Adobe: A building material made from clay-rich soil, water, and organic fiber (typically straw), formed into bricks and dried in the sun. One of the oldest building materials in continuous use.
Aquaponics: An integrated food production system combining fish cultivation (aquaculture) with plant growing (hydroponics) in a recirculating water system where fish waste provides nutrients for plants.
Bioclimatic design: Architectural design that responds specifically to the climate of a building’s location, using form, orientation, materials, and passive systems to achieve thermal comfort with minimal energy input.
Blackwater: Waste water from toilets, which contains fecal matter, pathogens, and concentrated nutrients. Requires more intensive treatment than greywater.
Botanical treatment cell: A constructed planter or growing bed designed to biologically process waste water through the combined action of filter media, microorganisms, and growing plants.
Charge controller: An electronic device that manages the flow of electricity from a solar PV array to a battery bank, preventing overcharging and optimizing battery charging profiles.
Cob: A natural building material made from clay, sand, and straw, worked as a plastic mass and applied by hand to form monolithic walls. Allows sculptural, curved forms.
Cistern: A container for storing harvested rainwater. Can be underground, above-ground, or integrated into a building’s structure.
Direct gain: A passive solar heating strategy in which sunlight enters directly through south-facing glazing and strikes thermal mass within the occupied space.
Diurnal temperature swing: The difference between the daily maximum and minimum temperature at a given location. Large diurnal swings (common in arid climates) favor the use of thermal mass in building design.
Earthship: A type of passive solar earth shelter developed by architect Michael Reynolds, characterized by tire walls, south-facing glazing, internal food production, and off-grid systems for energy, water, and waste treatment.
Embodied energy: The total energy consumed in extracting, processing, manufacturing, and transporting a building material, from its origin to its installation on-site.
First-flush diverter: A device that captures and diverts the initial, most contaminated flow of rainwater from a roof before allowing subsequent, cleaner water to enter storage.
Greywater: Waste water from sinks, showers, bathtubs, and laundry machines that has not come into contact with toilet waste. Lower in pathogens than blackwater but rich in nutrients.
Hempcrete: A building material made from hemp hurds, water, and lime binder, typically cast around a structural frame to provide insulation and moisture management.
Integrated design process: A collaborative design approach in which all building systems are considered simultaneously from the earliest stages, with all technical disciplines engaged throughout the design process.
Inverter: An electronic device that converts direct current (DC) electricity from batteries or solar panels to alternating current (AC) electricity for use in standard building electrical systems.
Lithium iron phosphate (LiFePO4): A lithium battery chemistry well-suited to off-grid energy storage, offering long cycle life, high usable capacity, and safety advantages over other lithium chemistries.
Microgrid: A local network of electricity generation, storage, and loads that can operate either connected to or independently of the utility grid.
Net positive: A design standard in which a building or community contributes more to ecological systems than it consumes, producing net environmental benefit rather than merely reduced harm.
Passive solar design: The use of a building’s orientation, form, glazing, thermal mass, and insulation to manage interior temperatures through passive means, without mechanical heating or cooling.
Peak sun hours: The number of hours per day of equivalent full-intensity sunshine at a given location, used for sizing solar PV systems.
Photovoltaic (PV): Technology that converts sunlight directly into electricity using semiconductor cells.
Rainwater harvesting: The collection and storage of rainwater for later use, typically from rooftop catchment areas directed to cistern storage.
Regenerative design: An approach to building and community design that aims to restore and strengthen ecological systems, going beyond sustainability to create net positive environmental outcomes.
Solar altitude: The angle of the sun above the horizon. Altitude is highest at solar noon and varies with season and latitude.
Solar azimuth: The compass direction of the sun. In the northern hemisphere, the sun is always in the southern sky (azimuth ranging from southeast in the morning to southwest in the afternoon).
Straw bale construction: A building method using compressed bales of straw (a byproduct of grain harvest) as the primary material for exterior walls, providing exceptional insulation.
Thermal mass: Dense, heavy materials (earth, concrete, stone, water) that absorb and store heat energy, moderating temperature fluctuations in buildings.
Thermosiphon: A passive fluid circulation system driven by density differences between warm and cool fluid, used in passive solar water heating systems without pumps.
Tire wall: A structural bearing wall system used in Earthship construction, built from automobile tires filled with rammed earth and stacked in a running bond pattern.
Trombe wall: A passive solar heating system consisting of a dense mass wall behind south-facing glazing that absorbs solar energy and releases it as heat into the building.
Water Organizing Module (WOM): A packaged assembly of filtration components, pumps, and controls for managing potable water treatment and distribution in an off-grid water system.