Single-Tenant Floor Measurement
BOMA measurement methodology for floors occupied by a single tenant, including treatment of floor common areas, corridors, and restrooms that become part of the tenant's usable area.
Methodology
On a single-tenant floor, the tenant's usable area equals the entire floor area minus major vertical penetrations (elevator shafts, stairwells, mechanical shafts) and any building common areas on the floor (shared mechanical rooms). Corridors, restrooms, and electrical closets that would be floor common area on a multi-tenant floor become part of the single tenant's usable area. The floor common area factor becomes 1.0 (no floor-level allocation needed).
BOMA 2017 vs 2024
BOMA 2024 maintains the principle that on a single-tenant floor, the entire floor becomes the tenant's usable area (excluding vertical penetrations and building common areas). The 2024 update adds guidance on partial-floor tenants who expand to take the entire floor — specifically addressing when and how remeasurement should occur.
Worked Example
A floor has 22,000 SF gross area. Vertical penetrations total 1,500 SF (two elevator shafts, two stairwells, mechanical shaft). Building common area on the floor is 500 SF (shared electrical switchgear room). Single-tenant usable area = 22,000 - 1,500 - 500 = 20,000 SF. With a building common area load factor of 1.12, rentable = 20,000 × 1.12 = 22,400 SF.
Financial Impact
Converting from multi-tenant to single-tenant measurement typically increases a tenant's usable area by 10-15% (the former floor common areas). However, the tenant is now paying for these corridors and restrooms as part of their usable area rather than through the load factor, so the net financial impact depends on the building's specific load factor structure.
Lease Implications
Leases for single-tenant floors should specify that measurement follows the BOMA single-tenant floor methodology. If a tenant later gives back part of the floor, the lease should address remeasurement provisions and how the floor will be reclassified under multi-tenant methodology.
Common Errors
- Deducting corridors and restrooms as floor common area on a single-tenant floor
- Failing to remeasure when a floor converts from multi-tenant to single-tenant
- Treating fire stair vestibules inconsistently between single and multi-tenant floors
- Not adjusting the building load factor when floor common areas shift from shared to tenant-exclusive
Additional Context
Single-tenant floor measurement is straightforward in concept but problematic in practice when floors transition between single and multi-tenant occupancy. The shift can change usable areas by 10-15%, triggering rent adjustments that surprise both landlords and tenants.
Related Resources
Catch Measurement Errors in Your Reconciliation
CapVeri validates pro-rata shares, load factors, and BOMA measurement consistency — catching errors before tenants or auditors find them.
Start Free Audit