C & D

Construction and Demolition.

Caliche

A type of soil containing calcium carbonate that makes a very hard brick/block without firing and is a common roadbed material.

Capillary action

Also known as wicking, it is the ability of a material to draw water into it through small pores or cracks.

Capitalization rate (Cap rate)

The rate, expressed as a percentage, at which a future income flow is converted into a present value figure.

Carbon cycle

The combined processes – including photosynthesis, decomposition, and respiration – by which carbon moves between the atmosphere, oceans, and living organisms.

Carbon dioxide (CO2)

A heavy, colorless gas that does not support combustion. Made of one carbon atom and two oxygen atoms, it is formed especially in animal respiration and in the decay or combustion of animal and vegetable matter. It is absorbed from the air by plants in photosynthesis, and is an atmospheric greenhouse gas.

Carbon Footprint™

A measure of the impact human activities have on the environment in terms of the amount of green house gases produced, measured in units of carbon dioxide.

Carbon monitor

These monitors regulate high CO2 levels in buildings, either by communicating with the ventilation system to bring in fresh air, or activate a fan, or by setting off an alarm alerting occupants to open a window.

Carbon monoxide (CO)

A colorless, odorless, very toxic gas made up of carbon and oxygen that burns to carbon dioxide with a blue flame and is formed as a product of the incomplete combustion of carbon.

Carbon neutral

Over its life cycle, a product or process that does not add more carbon dioxide to the atmosphere. For instance, a plant consumes carbon dioxide while it grows, then when transformed into and used as fuel such as ethanol it releases carbon dioxide back into the atmosphere. Plant-derived fuels have the potential to be carbon neutral.

Carbon offset

The process of reducing the net carbon emissions of an individual or organization, either by their own actions, or through arrangements with a carbon-offset provider.

Carbon sequestration

The capture and long-term storage of carbon dioxide before it is emitted into the atmosphere. One example: a system for filtering CO2 out of the emissions of a coal-fired power plant and pumping the CO2 deep underground.

Carbon sink

An area, such as the ocean, soil or forest, that absorbs and holds onto a large amount of carbon dioxide.

Carbon trading

Any trading system designed to offset carbon emissions from one activity (such as burning fossil fuels in manufacturing, driving, or flying) with another (such as installing more efficient technologies, planting carbon-reducing plants, or establishing contracts with others not to partake in carbon-releasing activities). The Chicago Climate Exchange (CCX) is the first and biggest carbon trading market in existence and is modeled on a stock market. When activities that reduce or capture carbon are paired successfully with those that produce it, these are said to be carbon neutral or climate neutral.

Carrying capacity

The amount of demand or usage for a particular resource that can be sustained without depletion or degradation of dependent life forms.

Car sharing

A system under which multiple households share a pool of automobiles, either through cooperative ownership or through another mechanism.

Cellulose

The fibrous part of plants used in making paper and textiles, which may be made into building products, such as insulation (see Wet-spray cellulose insulation).

Cementitious

Having the properties of cement. Cement is the primary binding agent in concrete.

Cementitious foam insulation

A magnesium-oxide based material blown with air to create an inert, effective insulation. It is especially good for people with chemical sensitivities. It has good fire retardation and sound-proofing qualities. It has the consistency of shaving cream when applied, and then hardens as it dries. It is made of air, water and cement.

Certified sustainably managed forest

Forest harvesting practices that have been certified as sustainable by a qualified entity. The underlying guideline is preservation of a diverse forest that exhibits the same ecological characteristics as a healthy natural forest.

Certified wood

Wood used in building construction that is supplied from sources that comply with sustainable forestry practices, protecting trees, wildlife habitats, streams, and soil. (See FSC).

CFC’s

Chlorofluorocarbons: any of a group of compounds that contain carbon, chlorine, fluorine, and sometimes hydrogen and have been used as refrigerants, cleaning solvents, aerosol propellants, and in the manufacture of plastic foams. CFCs have been linked to the destruction of the ozone layer and their use is being phased out because they destroy the planet's stratospheric ozone protection layer.

CFL

Compact fluorescent lighting: a fluorescent lamp/bulb that is compacted to fit into a standard Edison, or pin-based socket.

cfm

Cubic Feet per Minute: a measure of the volume of a substance flowing through air within a fixed period of time. With regard to indoor air, refers to the amount of air, in cubic feet, that is exchanged with outdoor air in a minute's time; i.e. the air exchange rate.

Chain-of-custody

A form of tracking certified wood products from the forest, through the mill, manufacturer and distributor to their final place of use. 

Change order

A form used by an architect or contractor to specify changes and revised pricing from the approved original plan.

Charrette

An intensive design process which involves the collaboration of all project stakeholders at the beginning of a project to develop a comprehensive plan or design. Although it may only take place over a few short days, it establishes groundwork for communication and a team-oriented approach to be carried throughout the building process (see Eco-charette).

Checkdam

Low dam of stone, wood, or other material used for holding and spreading runoff and sediment in a swale.

Chilled beam

These are overhead baffle units which, by natural convection from a finned heat exchanger, cool the air in a room. Some chilled beams can also incorporate a heating function. A chilled beam is a radiant cooling strategy.

Chiller

A device that generates a cold liquid that is circulated through an air-handling unit's cooling coil to cool the air supplied to the building.

CIR

Credit Interpretation Request: (LEED term) the Credit Interpretation Request (CIR) and ruling process was established for project applicants seeking technical and administrative guidance on how LEED credits apply to their projects and vice versa (see LEED).

Cistern

A tank to hold a supply of fresh water, typically rainwater. May be above or below ground.

Cleantech

An abbreviation of "clean technologies", a term used to describe knowledge-based products or services that improve operational performance, productivity, or efficiency while reducing costs, inputs, energy consumption, waste, or pollution. Its origin is the increased consumer, regulatory and industry interest in clean forms of energy generation—specifically, perhaps, the rise in awareness of global warming and the impact on the natural environment from the burning of fossil fuels.

CNG

Compressed Natural Gas: an alternative fuel for motor vehicles; considered one of the cleanest because of low hydrocarbon emissions and its vapors are relatively non-ozone producing. However, vehicles fueled with CNG do emit a significant quantity of nitrogen oxides.

Cob

Cob is made of clay-like lumps of soil, sand, and straw. Unlike adobe and straw bale construction, cob does not use bricks or blocks. Instead, wall surfaces can be sculpted into smooth, sinuous forms. A cob home may have sloping walls, arches and lots of wall niches. Cob homes are one of the most durable types of earth architecture. Because the mud mixture is porous, cob can withstand long periods of rain without weakening. A plaster made of lime and sand may be used to windproof the exterior walls from wind damage. Cob houses are suitable for the desert or for very cold climates.

Cogeneration

The simultaneous or sequential production of two or more forms of useful energy from a single primary energy source

Co-housing

Housing that combines the privacy of single-family dwelling units with extensive common facilities, such as kitchens, dining rooms, children’s playrooms, and laundry facilities, thus enhancing a sense of community. Residents often come together to identify a site and raise pre-development funds, making the development process much different than the usual development of communities.

Color temperature of light

Color appearance of a light. So called “warm” looking lights are actually cooler in temperature than “cool” looking lights. An incandescent light has a color temperature of about 2500; a cool white fluorescent light has a color temperature of about 4000 - 5500. The warmer an object is, the whiter its emitted light will be.

Combination foundation

Buildings constructed with more than one foundation type; i.e. basement/crawlspace or basement/slab-on-grade.

Combustion gases

The gases, such as carbon monoxide, resulting from the process of burning. In a building, these are produced by gas appliances, such as furnaces and water heaters. Proper venting must be assured.

Comfort

An important design objective in sustainable building. Designing for comfort aims to create a space where people enjoy being; such qualitative, performance-based objectives are a hallmark of sustainable building. Thermal comfort is the perception of comfort in response to air temperature, air speed, relative humidity and radiant surface temperature.

Construction and demolition (C&D) debris

C&D debris results from construction, remodeling, repair or demolition of buildings, roads or other structures. It includes (but is not limited to) wood, concrete, drywall, masonry, roofing, siding, structural metal, wire, insulation, asphalt, and packaging materials related to construction or demolition.

Comingled

Pure loads of Recyclable C&D Waste that contain mixed types of recyclable materials stored in one on-site container, which is taken to a sorting facility (MRF) where materials are separated for recycling. Comingled loads do not include non-recyclable material.

Commissioning

The process of ensuring, verifying, and documenting that new building equipment and systems are installed and able to operate according to the design intent.

Community

A factor with increased emphasis in sustainable building and sustainable development. Design and building related practices enhancing and supporting community ideals and functions are considered more sustainable than those that do not, all else being equal.

Composting

A waste management option involving the controlled biological decomposition of organic materials into a relatively stable humus-like product that can be handled, stored, and applied to the land without adversely affecting the environment.

Composting toilet

A toilet which uses little or no water in which the waste composts to a material which can be safely used as a soil amendment.

Condensation

Deposit of water vapor from air on a cold surface whose temperature is below the dew point. For example a cold window glass exposed to warm humid air.

Condensing boiler

A water heating device designed to recover energy normally discharged to the atmosphere through the flue. When a condensing boiler is working at peak efficiency the water vapor produced by the consumption of gas or oil in the boiler condenses back into water.

Conduction

Flow of heat through solid materials which are touching each other.

Conductor

A substance or body capable of transmitting electricity, heat, or sound.

Conservation

Achieving the use of less energy, either by using more efficient technologies or by changing wasteful habits.

Conservation easement

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

Constructed wetland

Any of a variety of designed systems that are modeled after natural wetlands, uses aquatic plants, and can be used to treat wastewater or runoff.

Construction loan

A loan usually made by a commercial bank to a builder or prospective homeowner for short-term use in constructing improvements on real estate (new construction or remodeling). The term is usually six months to two years. (A permanent mortgage is typically used for long-term financing.)

Container structure

A modular, replicable, self-contained, factory-built structure which is transported to a site where it is secured to a foundation, or placed on top of another container unit. Container structures have both residential and commercial applications.

Construction waste management

General term for strategies employed during construction and demolition to reduce the amount of waste and maximize reuse and recycling. Construction waste management is a sustainable building strategy in that it reduces the disposal of valuable resources, provides materials for reuse and recycling, and can promote community industries.

Convection

Transfer of heat by means of a moving stream of air or water.

Cooling/heating load

A building’s demand for heat/cool to offset a deficit/overage of the opposite.

Cooling tower

A device which dissipates the heat from water-cooled systems by spraying the water through streams of rapidly moving air. Cooling towers can be substantial water users, and provide an opportunity for water conservation.

Cool roof

Any roof with both reflective and emissive properties that reduce solar heat gains and improve the energy efficiency of the building envelope and mitigate the urban heat island effect.

Cradle-to-cradle

At the end of a products useful life, the product will decompose entirely with no negative environmental impact: otherwise it can be used as post-consumer material when recycled into a new product.

Cradle-to-grave

With no consideration for sustainability, these types of products are used for a period of time and then discarded, often long before their useful life is actually complete.

CRF

Condensation resistance factor: a indication of a window’s ability to resist condensation. The higher the CRF, the less likely condensation is to occur.

CRI

Color rendering index of light: the color objects will appear when illuminated by a given electric light. On a scale from 1 to 100, the higher a number, the more an object will look the color it actually is when illuminated by an electric light.

The same acronym is used for the Carpet and Rug Institute.

Cross ventilation

Passive building strategy to cool a building using outdoor breezes. Requires proper placement and sizing of doors, operable windows and walls to promote air movement through the building.

Cullet

Scraps of broken or waste glass gathered for re-melting, especially with new material.

Culvert

A sewer or drain running under a road or embankment.

CV

Constant Volume System: these HVAC systems deliver a constant airflow to each space. This is one of the two major types of HVAC systems based upon the use of airflow to control temperature. The other type of system is variable air volume (see VAV – variable air volume).