| Backfill |
| Imported or excavated soil used to fill around the foundation or to cover a trench. |
| Backprime |
| Priming the back of wood before it is applied to an exterior surface, such as cornice, door and window casings. |
| Baffle |
| Located in the attic near the eave vents, baffles provide an uninterrupted flow of air through the attic. |
| Baluster |
| A vertical member that supports the stair handrail. |
| Base molding (baseboards) |
| Horizontal molding used where the floor meets the wall. |
| Batt |
| A precut strip of insulation that fits between studs or joists. |
| Batten |
| A narrow vertical strip of wood used to cover two wider pieces of vertical wood. |
| Beam |
| A horizontal structural member made of wood or steel. |
| Bearing wall |
| A wall that supports part of the floor and/or roof above it. |
| Blocking/bridging |
| Short framing members that are used to brace the floor joists, usually at midspan. |
| Builder |
| See General Contractor. |
| Building codes |
| Regulations established by state and local governments stating the minimum standards for construction. |
| Building envelope |
| The limitations that a building’s volume may not exceed. The envelope is usually determined by setbacks and height limitations. |
| Building line |
| A line fixed at a certain distance from the front of the lot, behind which the home can be built. |
| Bulldozer (loader) |
| A tracked excavating machine used to move earth from one place to another. |
