Programming & Analysis: Pre-Design, Area, and Site/Code Analysis
Programming
Pre-design establishes goals, objectives, and a functional program: space types, areas, occupancy, adjacency, and growth. Programming precedes and drives design; skipping it is a common cause of later change orders.
Area accounting
Net (assignable) area excludes circulation, walls, and mechanical space; gross area includes everything within the building envelope. Efficiency = net ÷ gross, typically 65–85%. BOMA defines usable, rentable, and gross areas and the rentable/usable (R/U) ratio used in leases.
Site and zoning analysis
Analyze topography, soils, solar orientation, prevailing winter winds, noise, views, drainage, utilities, and access. Zoning controls use, floor area ratio (FAR), lot coverage, setbacks, height, and parking. Allowable gross floor area = site area × FAR; footprint × number of floors must satisfy both FAR and coverage.
Traps
FAR is a floor-area limit, not a footprint limit; lot coverage is a footprint limit, not a floor-area limit. Area questions often test whether you applied an efficiency factor in the right direction. Existing drawings are not a substitute for a field survey. Code occupancy classification drives egress and construction type, so classify early.
Worked example
A 40,000 sf site with FAR 2.5 permits 100,000 sf gross. At 60% lot coverage the footprint is 24,000 sf; over five stories that is 120,000 sf, so FAR governs and the building reaches only about 4.2 stories. At 80% efficiency, usable area is about 80,000 sf.