What are BOMA standards?

How it works

BOMA International publishes measurement standards for several building types, including office, industrial, retail, multi-family and mixed-use properties. The office standard, ANSI/BOMA Z65.1, is mainly used to calculate rentable area, which BOMA calls a crucial metric in office leasing. It also gives area figures for space utilization analysis, valuation, benchmarking and allocating building costs.

The method separates the area a tenant occupies (usable area) from the shared areas of the building, such as lobbies and corridors, and allocates a share of those common areas to each tenant. The result is rentable area. The ratio between rentable and usable area, often called the load factor, shows how much space a tenant pays for but cannot use directly.

The standards change over time. BOMA published its first office standard in 1915, and the current office edition is BOMA 2024 for Office Buildings. Because editions differ, two measurements of the same floor can give different results, so leases should name the edition used. BOMA is also a founding member of the coalition behind the International Property Measurement Standards (IPMS).

How to measure it

Check which BOMA edition and method each lease uses before comparing sites.
Use usable area for space planning and rentable area for cost comparisons, and label which one each report uses.
Ask for the measurement report behind any area figure in a lease or offer.

Examples

Two floors with the same usable area carry different rents because their buildings have different load factors.
A tenant has its space remeasured before renewal and finds the rentable area was calculated under an older edition.

Benchmarks

BOMA published its first office measurement standard in 1915.
BOMA International, BOMA Standards
BOMA's current office standard is BOMA 2024 for Office Buildings (ANSI/BOMA Z65.1-2024).
BOMA International, BOMA Standards

Common mistakes

Comparing cost per square foot across sites measured under different standards or editions.
Planning seats from rentable area, which includes common space nobody can sit in.
Assuming a BOMA measurement matches an IPMS measurement or a local standard.

Frequently asked questions

What does BOMA stand for?

The Building Owners and Managers Association. BOMA International publishes area measurement standards that are used in many real estate markets across the United States, Canada and internationally, and it is the American National Standards Institute secretariat for them.

What is the difference between rentable and usable area under BOMA?

Usable area is the space a tenant occupies. Rentable area adds a share of the building's common areas, such as lobbies and shared corridors. Office rent is usually charged on rentable area, so the gap between the two matters to tenants.

Which BOMA standard applies to offices?

The office standard, BOMA for Office Buildings: Standard Methods of Measurement. BOMA also publishes separate standards for industrial, retail, multi-family and mixed-use properties and for gross areas. Leases should name the edition used.

Rentable vs usable square feet Usable area is the space a tenant occupies; rentable area adds a share of common areas, and rent is charged on it.
Floor plate The area and shape of one floor of a building, which sets how many people, rooms and teams fit on it.
Space per person Office floor area divided by the number of people it serves, in square feet or square meters per person.
Lease management Tracking lease terms, critical dates, costs and obligations across a portfolio, and linking them to how each site is used.
Total occupancy cost Everything an organization spends to occupy a workplace in a year: rent, operating costs, utilities, services and fit-out.
CAD / DWG floor plans Architectural drawing files that provide the accurate geometry behind digital and interactive floor plans.

Sources

BOMA Standards, BOMA International

Kadence editorial team · Last reviewed October 1, 2026