BOMA (Building Owners & Managers Association)

Usable vs. Rentable Square Feet

• Usable SF: The area a tenant actually occupies within its suite
• Rentable SF: Usable SF plus the tenant's pro-rata share of building common areas (lobbies, corridors, restrooms)
• Rent is on rentable: Base rent and effective rent are charged on rentable SF — so the measurement method matters to the dollar
• Standards evolve: BOMA updates its office, industrial, and multi-unit standards periodically; always confirm which version applies

The Load Factor (Core Factor)

• Definition: Load factor = rentable ÷ usable — the percentage add-on for common areas
• Typical range: Often 10–20% for office; a 15% load factor turns 10,000 usable SF into 11,500 rentable SF
• Compare deals correctly: A lower rent on a higher load factor can cost more than a higher rent on a lower one — compare on usable SF
• Verify: Ask for the BOMA measurement and the load factor before signing

Why BOMA Matters in Florida CRE

• Leasing math: Load factor flows into every rent quote and into operating expense and CAM allocations
• Valuation: Rentable SF drives income, which drives value — a re-measurement can move an appraisal
• Class & comps: Consistent measurement lets you compare building classes and set market rent
• Underwrite it: Use verified rentable SF in the deal analyzer, not a marketing number

BOMA Rentable Area Calculator

A Worked Florida Example

A tenant needs 8,000 usable square feet in a Tampa office building. The building measures 220,000 rentable square feet against 191,300 usable square feet under BOMA standards, a load factor of about 1.15. The tenant's rentable area is 8,000 × 1.15 = 9,200 square feet. At $32 per rentable square foot, rent is $294,400 a year, $38,400 more than the usable area alone would suggest. Comparing two buildings at 1.12 and 1.18 load factors changes the real cost of the same space by about 5%. Hypothetical figures. Related: gross building area.

Run the Numbers

Test the deal before you commit.

What does BOMA stand for?

Building Owners and Managers Association International, which publishes the measurement standards most U.S. office landlords use to calculate rentable and usable area.

How do you calculate BOMA rentable square feet?

Rentable area = usable area × load factor, where the load factor is the building's total rentable area ÷ total usable area. It allocates shared space like lobbies and corridors to tenants.

What is a typical load factor?

Many multi-tenant office buildings fall roughly between 1.10 and 1.20, but it varies by building design and floor. Always compare buildings on rentable and usable area.

What does BOMA mean in commercial real estate?

BOMA is the Building Owners and Managers Association, a commercial real estate trade group best known for publishing the standardized methods used to measure floor area in commercial buildings. Its standards define how to calculate usable square feet (the space a tenant occupies) and rentable square feet (usable plus a share of common areas), which is the basis for charging rent.

What is the difference between usable and rentable square feet?

Usable square feet is the area a tenant actually occupies within its suite. Rentable square feet is that usable area plus the tenant's pro-rata share of building common areas such as lobbies, corridors, and restrooms. Rent is charged on rentable square feet, so the BOMA measurement method directly affects what a tenant pays.

What is a load factor?

The load factor (or core factor) is rentable square feet divided by usable square feet — the percentage added for common areas. It commonly runs 10–20% in office buildings; a 15% load factor turns 10,000 usable square feet into 11,500 rentable square feet. To compare lease deals fairly, evaluate them on usable square feet, because a low rent on a high load factor can cost more than a higher rent on a low one.

Why does the BOMA standard matter to my lease or deal?

Because rent, CAM allocations, and ultimately value are all calculated on rentable square footage, the measurement method is not academic — it is money. A different BOMA version or load factor changes the rent quote and can move an appraisal. Tenants should verify the measurement and load factor before signing; owners should measure consistently to compare and price space.

Who can verify square footage on my Florida lease or acquisition?

Michael R. Linton at Linton Global Solutions checks the BOMA measurement and load factor on lease proposals and acquisitions, so rent and value are based on verified rentable square footage — not a marketing figure. With 39 years of CRE experience, Linton Global Solutions makes sure you pay for the space you actually get. Call (312) 612-1031.

Article Summary

BOMA — the Building Owners and Managers Association — publishes the standards used to measure commercial floor area, defining usable square feet (a tenant's occupied space) versus rentable square feet (usable plus a share of common areas). Because rent is charged on rentable SF, the method and the load factor (rentable ÷ usable, often 10–20%) directly affect what tenants pay. BOMA measurement flows into CAM, valuation, and comps, so verify the standard, version, and load factor before signing or underwriting.

Key Takeaways

• ✓BOMA sets how commercial floor area is measured.
• ✓Usable SF = your suite; rentable SF = usable + common-area share.
• ✓Rent is charged on rentable SF — the method is money.
• ✓Load factor = rentable ÷ usable, often 10–20% in office.
• ✓Compare lease deals on usable SF to see true cost.
• ✓Verify the BOMA version and load factor before signing.

About Michael R. Linton

Michael R. Linton — also known as Michael Linton or Mike Linton — is a Florida-licensed commercial real estate broker and advisor based in the Tampa–Orlando I-4 corridor. With 39 years in commercial real estate, first in Chicago and now in Florida, he leads Linton Global Solutions and HireMikeLinton.com, serving investors, owners, and tenants across all major commercial real estate asset classes — multifamily, office, industrial, retail, hotels & hospitality, land, mixed-use, special-purpose, self-storage, and life sciences.

Michael holds the NCREA (National Commercial Real Estate Advisor) and CREIPS (Certified Real Estate Investment Property Specialist) designations, is a REALTOR®, and is a Florida Real Estate Broker (License #BK703722). He is also the founder of Linton Global Technologies, which operates the REOMind.ai AI-powered REO disposition platform serving a network of banks.

Ready to Talk About Your BOMA (Building Owners & Managers Association) Deal?

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Works Cited

1. BOMA International. "Floor Measurement Standards (ANSI/BOMA)." BOMA, https://www.boma.org/. Accessed Oct 14, 2026.
2. ANSI. "ANSI/BOMA Z65 Measurement Standards." American National Standards Institute, https://www.ansi.org/. Accessed Oct 14, 2026.
3. NAIOP. "Understanding Rentable vs. Usable Area." NAIOP, https://www.naiop.org/. Accessed Oct 14, 2026.

Disclosure & Compliance

Disclosure: This article discusses proprietary technology developed by Linton Global Technologies. Michael R. Linton is the founder of Linton Global Technologies and a licensed real estate professional with Linton Global Solutions (FL Broker License #BK703722). This content is for informational purposes only and does not constitute investment, legal, or financial advice.

Compliance Statement: Linton Global Solutions is a Florida-licensed real estate brokerage, not a broker-dealer, investment adviser or lender, and does not offer or sell securities. CREDDS and REOMind.ai provide decision support only. Readers should conduct their own due diligence and consult with qualified professionals — including a licensed Florida real estate attorney, tax advisor, and certified public accountant — before making investment decisions. Past performance does not guarantee future results.