Terms

Abatement : The encapsulation or removal of building materials containing pollutants (such as lead or asbestos) to prevent the release of or exposure to fibers.

Above Finished Floor : Datum or benchmark for measuring the height above a floor, abbreviated as AFF.

Abrams’ Law The rule stating that with given materials, curing, and testing conditions, concrete strength is inversely related to the ratio of water to cement. Low water-to-cement ratios produce high strengths.

Accelerating Admixture : An admixture for hydraulic concrete that shortens setting time and inhibits early strength development.

Access Control System : Computerized building security equipment, such as badge readers, designed to protect against unauthorized entry into buildings or building zones.

Access Door / Access Panel : A means of access for the inspection, repair, or service of concealed systems, such as air-conditioning equipment.

Access Flooring : A raised flooring system with removable panels to allow access to the area below.

Acoustical Ceiling : A ceiling system constructed of sound-control materials. The system may include lighting fixtures and air diffusers.

Acoustical Metal Deck A metal decking that includes a sound- absorbing material installed at a small additional cost per square foot.

Acoustical Panel : Modular units composed of a variety of sound.

Active Leaf : In a double-leaf door, the leaf to which the latching or locking mechanism is attached.

Activity : In critical path method (CPM) scheduling, a task or item of work required to complete a project. Also called task.

American Disabilities Act (ADA) : A set of standards that establish minimum technical requirements for the design and construction of buildings and facilities. Their intent is to increase the level of accessibility in the built environment, in existing facilities as well as new construction and alterations.

Addendum : A document describing an addition, change, correction, or modification to contract documents. An addendum is issued by the design professional during the bidding period or prior to the award of contract, and is the primary method of informing bidders of modifications to the work during the bidding process. Addenda become part of the contract documents.

Addition : An expansion to an existing structure, generally in the form of a room, floor, or wing. An increase in the floor area or volume of a structure.