Construction Glossary
Quick reference for terminology appearing in calculators, results, and project guides. Spanish translations appear in the Spanish glossary page.
- Board foot
- A lumber volume unit equal to 144 cubic inches — commonly used for hardwood pricing.
- Bundle (roofing)
- A packaged unit of asphalt shingles; typically three bundles cover one roofing square.
- Coverage rate
- Area a material covers per unit (e.g., square feet per gallon of paint).
- Cubic yard (yd³)
- US volume measure equal to 27 cubic feet; common for concrete, mulch, and bulk soil.
- On center (OC)
- Spacing measured from the center of one framing member to the next (e.g., 16 in OC studs).
- Pitch (roof)
- Roof slope expressed as rise over run (4/12 means 4 in rise per 12 in horizontal run).
- R-value
- Thermal resistance of insulation; higher numbers mean better resistance to heat flow.
- Riser
- Vertical face of a stair step between treads.
- Roofing square
- 100 square feet of roof area; shingle orders often reference squares.
- Tread
- Horizontal walking surface of a stair step.
- Waste factor
- Extra material percentage added to net quantity to cover cuts, breakage, and errors.
- Markup
- Percentage added to cost to reach selling price (markup% of cost).
- Margin
- Profit as a percentage of selling price (different from markup).
- BTU
- British Thermal Unit — heat energy rate used to size heating and cooling equipment.
- Manual J
- ACCA standard for residential HVAC load calculation; more detailed than rule-of-thumb sizing.
- Premix concrete
- Dry concrete mix in bags requiring water on site; yield varies by bag weight.
- Roll-off dumpster
- Open-top waste container delivered for construction debris; sized in cubic yards.