BOMA 2017 Office Standard — Method A

BOMA Area Calculator

Calculate rentable vs usable area per the Building Owners and Managers Association (BOMA) 2017 Office Standard. Compute gross measured area, floor and building add-on factors, load factor, and building efficiency — essential for commercial leasing, real estate valuation, and Revit area planning.

Building Information

Building Name

Building Type

Floor-by-Floor Area Data

2 floors · all areas in SF

FloorGMA (SF)Floor Common (SF)Bldg Common Alloc (SF)Major Vertical (SF)

TOTALS24,000 SF1,750 SF400 SF1,200 SF

Field Definitions (BOMA 2017 §3)

GMA — Gross Measured Area: total area within exterior wall dominant portion

Floor Common — Lobbies, corridors, restrooms serving multiple tenants on the floor

Bldg Common Alloc — Each floor's share of building-wide common areas (main lobby, amenities)

Major Vertical — Elevator shafts, stairwells, mechanical shafts (excluded from rentable)

Per-Floor Results

FloorGMA (SF)Usable (SF)Rentable (SF)Add-On FactorLoad Factor

Floor 112,00010,50011,5187.9%9.7%

Floor 212,00010,55011,5267.5%9.2%

Office Tower A — Summary

Total GMA

24,000 SF

Gross Measured Area

Total Usable Area

21,050 SF

Net assignable area

Total Rentable Area

23,043 SF

Billable to tenants

Building Add-On Factor

1.67%

Bldg common / total GMA

Overall Load Factor

9.5%

Building Efficiency

91.3%

Avg Load Factor

9.5%

Floors

Highest load floorFloor 1 · 9.7%

Lowest load floorFloor 2 · 9.2%

BOMA 2017 Method A Formulas

UA = GMA - Floor Common - MV
F_AOF = Floor Common / (GMA - MV)
B_AOF = Bldg Common / ΣGMA
RA = UA × (1+F_AOF) × (1+B_AOF)
LF = (RA - UA) / UA × 100
Eff = UA / RA × 100
MV = Major Vertical Penetrations

Typical Load Factors (BOMA Reference)

Single-tenant office0 – 5%

Multi-tenant floor8 – 12%

Building common3 – 8%

Total (combined)10 – 20%