Glossary of Construction Terms

Do you ever feel as if your contractor is selling you polyisocyanurate foam when what you really needed was a setback thermostat? Here is a handy guide to common (and not so common) construction terms. Scroll through the glossary below or sort by the letter that starts the word you're looking for. For example, to find polyisocyanurate foam, select P and click Submit.

A (7) | B (6) | C (18) | D (8) | E (9) | F (8) | G (2) | H (4) | I (1) | J (1) | L (4) | M (3) | O (2) | P (11) | R (10) | S (19) | T (7) | U (1) | V (1) | W (4) | Z (2)
Title Definition

A type of black plastic pipe commonly used for waste water lines.


A sum of money set aside in the construction contract for items which have not been selected and specified in the construction contract. Best kept to a minimum number and used for items who's choice will not impact earlier stages of the construction. For example, selection of tile as flooring may require an alternative framing or underlayment material.

Arc Fault Current Interrupters AFIs or AFCIs

These are new electrical safety devices and are becoming part of the electrical codes. AFIs are designed to prevent electrical fires and should not be confused with GFIs. AFIs are recommended for bedroom areas.

See also: Topics: Consumer News, Consumer Products Safety Commission

Amperage or AMPS

A unit of electrical current or volume, see "Voltage." Most homes have an electrical service 'entrance' package of 125 or 200 amps. Some older homes have 60 or 100 amp 'entrances'.

See also: Topics: Electrical Systems, Q&A: Amps, Volts and Watts

Anchor Bolts

'L' shaped bolts which are set in the concrete foundation and used to attach the framing of the house to the foundation (see diagram).
Anchor Bolt


One who has completed a course of study in building and design, served an internship and passed a test and is licensed by the state as an architect.


A common form of magnesium silicate which was used in various construction products due to it's stability and resistance to fire. Asbestos exposure, by inhaling loose asbestos fibers, is associated with various forms of lung disease.

See also: EPA Asbestos in Your Home, Q&A: Encapsulating Asbestos, Q&A: Does My Insulation Contain Asbestos, Q&A: Is This Asbestos?, Q&A: Asbestos Floor Tiles, Q&A: Asbestos Ceiling Tiles

Some heating ducts with damaged asbestos tape.
The hole maybe a rodent access point.
It is also a defect in the duct system.