BOMA 2024 Changes: What the Updated Standards Mean for Your CAM Bill
BOMA 2024 refers to the Building Owners and Managers Association's updated measurement standards for office buildings, released in 2024. The revision modifies how certain building areas are classified, measured, and allocated between leasable and non-leasable categories. For commercial tenants, these changes affect the denominator used to calculate pro-rata share, which directly affects how much each tenant pays for CAM charges.
Most tenants do not know which BOMA standard their lease references, let alone what changed in 2024. This guide explains the relevant changes, how they affect CAM billing, and what lease language protects you from unexpected share increases due to remeasurement.
Key Takeaways
- BOMA 2024 modifies how certain shared spaces (building amenities, service areas, and multi-tenant corridors) are classified, which can change both tenant and building RSF.
- If your lease specifies a particular BOMA standard, the landlord cannot unilaterally remeasure under a different standard without a lease amendment.
- Remeasurement under BOMA 2024 may increase or decrease your pro-rata share depending on the building's configuration.
- BOMA standards apply primarily to office leases. Retail leases typically use ICSC/GLA definitions that follow a different methodology.
- The practical protection for tenants is explicit lease language locking the denominator to a specific BOMA standard and year.
What BOMA Standards Are and Why They Matter
The Building Owners and Managers Association publishes measurement standards that define how rentable area is calculated for office and other commercial building types. (Source) The standards are not law; they are voluntary industry conventions. Their importance is that most commercial leases adopt BOMA standards by reference.
A lease that says "rentable area as determined by BOMA standards" leaves open which version applies. A lease that says "rentable area as determined by the 2017 BOMA standard for office buildings" is explicit.
Different BOMA versions use different formulas for the "load factor" or "R/U ratio" : the multiplier that converts usable area (the physical space within a tenant's walls) to rentable area (the space including an allocated share of building common areas). A higher load factor produces a higher RSF for the same usable area.
The load factor impact on rent and CAM:
If your usable area is 4,000 SF and the load factor is 1.15, your rentable area is 4,600 SF. Under a different BOMA standard with a 1.12 load factor, your rentable area would be 4,480 SF. The difference (120 SF) affects both your base rent and your pro-rata share calculation.
For pro-rata share: if your RSF changes from 4,600 to 4,480 while the building denominator stays constant, your share decreases. If your RSF stays constant but the building denominator changes due to reclassification of common areas, your share may increase or decrease depending on the direction.
What Changed in BOMA 2024
BOMA 2024 is a revision to the 2017 standard. The key changes relevant to tenants:
| Area | BOMA 2017 Treatment | BOMA 2024 Treatment | Impact |
|---|---|---|---|
| Building amenity spaces | Allocated as building common area | May be classified differently depending on shared-use criteria | Can change building denominator |
| Service areas (mechanical rooms, etc.) | Included in floor common area allocation | Revised allocation methodology | Can affect load factor |
| Exterior covered areas | Variable treatment | Clarified classification rules | May affect tenant RSF |
| Multi-tenant floor corridors | Floor-level common area | Updated allocation approach | Can change per-floor load factor |
The practical effect of these changes depends on the specific building configuration. Not every building will be affected equally, and some buildings will see minimal changes when remeasured under BOMA 2024.
BOMA 2024 vs. BOMA 2017: The Specific Changes
| What Changed | BOMA 2017 | BOMA 2024 | Impact on Your CAM |
|---|---|---|---|
| Ground-level outdoor amenities | Excluded from rentable SF | Patios, terraces, and courtyards now included | Expands denominator; dilutes your share slightly if your space did not change |
| Balconies and rooftop terraces | Load factor penalty applied | Classified as Non-Allocated Tenant Area; measured at 100%, no load factor | Eliminates RSF discount on premium amenity space |
| Base building circulation (Method B) | Complex multi-step allocation | Simplified proportional floor allocation | Reduces disputes; small RSF increase per floor |
| Tenant storage areas | Multiple classification categories | Single streamlined category | Cleaner pro-rata allocation; fewer CAM exclusions |
| Single-tenant equipment shafts | Excluded or ambiguous | Explicitly billable RSF | Incremental addition to total building SF |
Net effect across a typical commercial portfolio: a 2–5% increase in total rentable SF per building when adopting BOMA 2024 from BOMA 2017.
To see the math: a 150,000 RSF office building where a tenant occupies 10,000 RSF starts at a 6.67% share. Under BOMA 2024, the building remeasures to 157,500 RSF (a 5% increase). If the tenant's space stays at 10,000 RSF, the share drops to 6.35%. On a $500,000 annual CAM pool, that's the difference between $33,333 and $31,746, a $1,587 annual reduction. If the landlord adopted the new building total but did not adjust the tenant's share, the tenant may be overpaying by that amount each year.
The Non-Allocated Tenant Area problem
The most impactful single change in BOMA 2024 is the reclassification of balconies and rooftop terraces as "Non-Allocated Tenant Areas" (NATA). Under BOMA 2017, these spaces carried a load factor the same as interior tenant areas. Under BOMA 2024, they are measured at 100% of their actual area with no load factor applied.
In a mixed-vintage lease book, where some leases were signed under BOMA 2017 measurements and others under BOMA 2024, the two standards produce different denominators. If you are a tenant in a building with balconies or rooftop terraces and your landlord adopted BOMA 2024, verify whether your own space was remeasured and whether the pro-rata share in your reconciliation reflects a consistent measurement methodology.
How Remeasurement Can Affect Your Pro-Rata Share
Landlords remeasure buildings when: they are seeking BOMA certification, they are refinancing and need updated square footage figures, they are executing new leases and want current measurement documentation, or they are disputing a tenant's measurement claim.
Scenario A: Your RSF increases, building total stays constant. Your numerator increases, your share increases, your annual CAM bill increases.
Scenario B: Your RSF stays constant, building total changes. If the denominator increases, your share decreases. If the denominator decreases (due to reclassification of some area as non-leasable), your share increases.
Scenario C: Both change in the same direction. The net effect depends on which changes more proportionally.
Scenario D: The BOMA standard changed but your lease is explicit. If your lease specifies "BOMA 2017 standard" and the landlord remeasures under BOMA 2024, the remeasurement does not affect your lease obligations. The landlord may use the new measurement for new leases but cannot impose it on existing leases without your consent.
Lease Language: What Protects You and What Doesn't
Strong protection: Lease language that explicitly locks the measurement standard and the denominator RSF:
"Tenant's pro-rata share shall be calculated using (a) the rentable square footage of the Premises as set forth in Section 1 of this Lease, and (b) the total rentable area of the Building as of the Commencement Date, as measured under the BOMA 2017 standard for office buildings, being [specific RSF]."
This language sets both your numerator and the denominator at fixed values. Neither can change without a lease amendment.
Weak protection: Language that references "BOMA standards" without specifying a year or that reserves the landlord's right to remeasure:
"Tenant's pro-rata share shall be based on the rentable area of the Premises relative to the total rentable area of the Building, as such areas may be measured or remeasured from time to time."
"From time to time" gives the landlord unilateral remeasurement rights, which can increase your share after a new measurement standard is adopted.
No protection: Leases that are silent on measurement standard. These leave the applicable standard open to interpretation, creating ambiguity that landlords typically resolve in their own favor.
Specific BOMA 2024 Changes and Their Tenant Impact
BOMA 2024 introduced several classification and allocation changes from the 2017 standard. While the full technical specification requires access to the BOMA publication, the changes relevant to tenants fall into three practical categories:
Change 1: Building amenity area classification
BOMA 2024 revised how amenity spaces shared by all building tenants are classified and allocated. Spaces like fitness centers, conference rooms, and common lobbies may be classified differently depending on whether their use is shared among all tenants, available only to certain floors, or functionally tied to specific tenant suites.
Under BOMA 2017, many amenity spaces were allocated as building-wide common area, adding load factor to all tenants equally. Under BOMA 2024, the classification is more specific, which can shift how load factor is distributed. Some tenants on floors near amenity spaces may see higher load factors; those on other floors may see lower ones.
Tenant impact: If building amenities changed classification, your RSF may have changed even though your physical space is identical. Request the pre- and post-remeasurement RSF figures and the specific classification that changed.
Change 2: Service and mechanical area allocation methodology
BOMA 2024 updated the methodology for allocating service areas : mechanical rooms, elevator shafts, stairwells, and janitorial closets : across floor-level common area calculations. The change affects the "floor common area factor," which is one component of the total load factor.
Buildings with large mechanical footprints may see different load factor distributions after BOMA 2024 remeasurement than under BOMA 2017. In most office buildings, this change produces modest RSF adjustments (typically less than 1% to 3% of tenant RSF), but on a 5,000 SF tenant in a large building with significant mechanical infrastructure, even a 2% adjustment can change annual CAM by thousands of dollars.
Change 3: Exterior covered area treatment
BOMA 2024 clarified the treatment of covered exterior areas: covered parking, exterior corridors, loading docks, and similar spaces. Under BOMA 2017, the treatment varied by property; under BOMA 2024, the classification rules are more explicit.
For tenants in buildings where exterior covered areas were previously unclassified or classified inconsistently, BOMA 2024 remeasurement may reclassify those areas in ways that affect the total building RSF and, consequently, each tenant's pro-rata share.
How to Audit a Post-BOMA 2024 Remeasurement
If your landlord has remeasured the building under BOMA 2024 and your pro-rata share has changed, this is an auditable event. The audit process for a remeasurement dispute differs from a standard CAM overcharge review:
Document request 1: The remeasurement report. Request the full BOMA certification or measurement report. This document should show the methodology, the classification decisions made for each space type, and the resulting RSF figures for both tenant and building.
Document request 2: The prior measurement basis. Request the prior RSF documentation: the measurement basis used before BOMA 2024 was applied. Without this, you cannot calculate the change or verify whether the new figures are correct.
Document request 3: The lease definition. Your lease's pro-rata share and RSF definitions govern whether the new measurements apply. If the lease specifies BOMA 2017 or locks in a specific RSF number, those provisions override the remeasurement.
Verification step: If both the tenant RSF and the building total RSF changed, calculate each percentage and compare. A building that went from 120,000 to 125,000 SF while your space went from 5,000 to 5,100 SF does not produce the same share change as a building that stayed at 120,000 SF while your space went to 5,100 SF. The net effect of both numbers changing simultaneously requires careful math.
BOMA and Retail Properties: A Different Standard
BOMA 2024 applies primarily to office buildings. Retail properties use the International Council of Shopping Centers (ICSC) gross leasable area (GLA) definition, which operates differently:
- GLA measures the total floor area designed for tenant use and exclusive occupancy
- GLA typically excludes anchor tenant areas from the denominator in some shopping center contexts
- Retail leases specify GLA rather than BOMA RSF as the allocation basis
Retail tenants should verify which standard their lease uses. A retail lease that references BOMA instead of ICSC/GLA may produce a different share calculation than intended, particularly in mixed-use properties where parts of the building are office-classified.
What to Do If Your Landlord Remeasures
If you receive a notice that the building has been remeasured and your pro-rata share is changing:
Review your lease immediately. Check whether the lease specifies a measurement standard, locks the denominator RSF, or contains remeasurement rights language.
Request the remeasurement documentation. Ask for the BOMA certification or measurement report, the methodology used, and the specific changes to your tenant RSF and the building total RSF.
Compare before and after. Calculate your pre-remeasurement share and your post-remeasurement share. Determine the annual dollar impact.
Evaluate your dispute rights. If the lease specifies a particular BOMA standard and the landlord remeasured under a different one, you have grounds to dispute the new allocation. If the lease is silent, the dispute is more difficult but still worth evaluating.
Consult a tenant representative. Remeasurement disputes are fact-intensive and often require a property-specific analysis. A tenant representative broker or commercial real estate attorney can evaluate whether the remeasurement complies with your specific lease.
Frequently Asked Questions
What is BOMA 2024 and why does it affect CAM billing?
BOMA 2024 is the Building Owners and Managers Association's updated measurement standard for office buildings. It changes how certain shared spaces are classified and allocated, which can affect the denominator used to calculate a tenant's pro-rata share of CAM expenses. A different denominator produces a different percentage, which directly changes the annual CAM bill.
Can my landlord remeasure my space without my consent?
It depends on your lease language. If the lease specifies a particular BOMA standard or locks the denominator RSF, the landlord cannot change the calculation without a lease amendment. If the lease reserves the landlord's right to remeasure 'from time to time,' remeasurement may be permitted. If the lease is silent on measurement standard, the dispute is more ambiguous.
Does BOMA 2024 apply to retail leases?
No. BOMA 2024 applies to office buildings. Retail properties typically use the International Council of Shopping Centers gross leasable area definition, which operates under a different methodology. Some retail leases in mixed-use properties may reference BOMA standards, but this is uncommon. Most retail CAM share calculations use ICSC GLA rather than BOMA RSF.
What lease language locks my pro-rata share denominator?
Strong protection language explicitly states (1) the specific BOMA standard by year, (2) the denominator RSF as a fixed figure as of the commencement date, and (3) that the denominator will not be changed without a lease amendment. Avoid language that reserves the landlord's right to remeasure 'from time to time' without specifying what standard applies and whether the remeasurement can change your share.
If BOMA 2024 increases my RSF, can I dispute the new CAM calculation?
Yes, if your lease specifies the 2017 standard or locks the RSF. Review your lease's measurement and pro-rata share provisions. If you believe the new RSF violates your lease terms, send a written dispute before your lease's dispute window closes. Request the full remeasurement documentation from the landlord under the audit rights clause.
2026 update: which landlords have adopted BOMA 2024 and what it means
Two years after publication, BOMA 2024 adoption is uneven. Here is what the landscape looks like in 2026 and why it matters for tenants renewing leases or entering new buildings.
Which landlord types are most likely to have switched
Institutional landlords and REITs with large office portfolios have the strongest incentive to adopt BOMA 2024. These organizations seek BOMA certification for their flagship assets because certification affects asset valuation, LEED interoperability, and lender requirements. If your building is owned by a publicly traded REIT or a large institutional investment manager (think Blackstone, Brookfield, CBRE Investment Management, or Nuveen), there is a higher probability that the building has been remeasured under BOMA 2024 in the last 18 months.
Regional and local landlords are slower to adopt. A family-owned office building with long-term tenants and no near-term refinancing or sale has little incentive to pay for a new BOMA measurement certification when the prior measurement is already documented and accepted by existing tenants.
Single-tenant net lease buildings present the least exposure. When one tenant occupies the entire building, there is no pro-rata denominator to argue about. BOMA 2024 only creates material risk when there are multiple tenants whose shares must add up to 100%.
How to tell if your lease uses BOMA 2024 vs. BOMA 2017
The clearest signal is in your lease document itself. Look for the measurement standard reference in the pro-rata share definition or the premises description section. A lease referencing "BOMA 2017" or "ANSI/BOMA Z65.1-2017" is locked to that standard. A lease referencing "BOMA standards" without a year, or "current BOMA standards as amended from time to time," is open to interpretation.
If your lease was signed before 2024 and the building has since been remeasured, request the BOMA measurement certificate from your landlord. The certificate will state the measurement standard used, the date of the measurement, and the resulting RSF figures. Compare those to what your lease states. If the building's current BOMA measurement was done under the 2024 standard but your lease references 2017, the newer measurement does not bind you.
For leases signed in 2025 or 2026, ask during negotiation which BOMA standard was used to measure the premises and request that the specific version be cited in the lease. New leases signed against a BOMA 2024 measurement will typically reference the 2024 standard explicitly. Locking both your numerator and the building denominator to a specific standard and a specific date prevents future disputes.
The practical implication for reconciliation review: if your building was remeasured but your lease predates 2024, pull your prior reconciliations and compare the pro-rata percentage applied. If it changed without a corresponding lease amendment, that is an auditable event. The CAM reconciliation process guide explains how to trace pro-rata share changes through reconciliation history.
How tenants should respond to a BOMA 2024 lease amendment
When a landlord asks a tenant to sign a lease amendment reflecting a BOMA 2024 remeasurement, the tenant has a choice: accept the new figures, negotiate modifications, or decline. Here is a framework for evaluating that choice.
What to ask for in writing before signing anything
Before agreeing to any remeasurement amendment, request in writing:
- The full BOMA 2024 measurement certificate for the building, signed by the certifying architect or measurement professional.
- The prior BOMA measurement certificate or documentation so you can compare before and after.
- A calculation showing how the new building total RSF affects your pro-rata share under the proposed amendment.
- Confirmation of whether any other tenants in the building have signed the same amendment, or whether you are being asked first.
- The landlord's explanation of why the remeasurement is being pursued now.
The last question matters. If the landlord is requesting a BOMA 2024 amendment because a new tenant is taking space and the landlord needs consistent measurements across all leases for financing purposes, that is a legitimate operational reason. If the landlord is requesting the amendment because it produces a higher pro-rata share for existing tenants and reduces the landlord's contribution to CAM, that is a different situation.
When to accept vs. negotiate
Accept the amendment if: (a) the new pro-rata share is lower or roughly the same as the prior share, (b) the new figures are independently verified by the measurement certificate, and (c) the amendment locks the new denominator in the same explicit way the prior lease ideally should have.
Negotiate if: the new pro-rata share is materially higher and the increase benefits the landlord by reducing their absorbed share of CAM. In this scenario, ask for a corresponding reduction in base rent per square foot (since the remeasured RSF is now different from the RSF on which original rent was negotiated), a fixed denominator that freezes the building total RSF for the remainder of the lease term, or a phase-in provision that steps up the new share over two to three years rather than applying the full change immediately.
Decline if: the remeasurement is inconsistent with the measurement certificate, you cannot verify that the methodology was correctly applied, or the landlord refuses to provide documentation supporting the change.
What a re-measurement clause looks like and the red flags
A re-measurement clause allows the landlord to periodically remeasure the building and adjust tenants' pro-rata shares based on the results. These clauses range from innocuous to heavily landlord-favorable. The key provisions to review:
The phrase "as measured from time to time" is the primary red flag. It gives the landlord unilateral discretion to remeasure at any time for any reason and adjust your share. Paired with no cap on how much the share can change, this is an open-ended tenant exposure.
A tenant-protective re-measurement clause would specify: (a) the measurement standard by name and year, (b) that remeasurement may only be triggered by a specific event (new lease, refinancing, sale), (c) a cap on how much the denominator can change from the prior certified measurement, and (d) tenant review rights before the new figures take effect.
For gross-up calculation issues that frequently accompany BOMA 2024 adoptions in office buildings, see the gross-up calculation guide.
Related Resources
Pro-rata share and measurement:
- Pro-rata share calculator : Verify your percentage with correct denominator
- Common area maintenance reconciliation tenant guide
- NNN lease audit guide
Lease language:
Tools:
- Pro Rata Share Calculator : Verify your denominator
- CAM Overcharge Estimator
- Start Free Audit