The whole wall.

Room measurements turned into the things a finish job actually consumes: gallons and quarts of paint, single rolls of paper with the pattern repeat allowed for, sealed boxes of flooring, and sheets of drywall with the screws, tape and compound that always get left off the list.

Everything that arrives by the yard, the ton or the truckload — mulch, topsoil, gravel and concrete — plus the framing counts for the two projects most often built over them: a fence run and a deck surface. Bulk material is bought in supplier increments, so these round the way the yard rounds.

Conductor sizing against the NEC ampacity tables, voltage drop over a long run, conduit fill, a dwelling service load, generator sizing and a recessed-lighting layout. Each one prints the table and the article it read from, because an inspector will ask. These size and sanity-check a plan; they do not replace a licensed electrician or a permit.

Cooling load in BTU per hour and electric heat in watts, both from the same room facts: floor area, ceiling height, insulation, sun and climate. Sizing close to the real load matters more than buying big — an oversized air conditioner short-cycles and leaves a room cold and clammy.