BOMA 2024 and CAM Reconciliation: What Changed and What Landlords Must Do
BOMA/ANSI Z65.1-2024 introduced new measurement methodology for outdoor amenity areas, semi-enclosed structures, and transitional zones. For landlords, the critical question is whether your leases reference a specific BOMA standard — and whether remeasuring under the 2024 standard changes your pro-rata denominators.
By Angel Campa, Founder, CapVeri · Updated April 2026
Quick Answer
BOMA 2024 (BOMA/ANSI Z65.1-2024) introduced new methodology for measuring outdoor areas, semi-enclosed spaces, and transitional zones. For landlords, the key question is: does your lease reference a specific BOMA standard? If so, does the 2024 standard change your denominator? BOMA 2024 applies to existing leases only if the lease references BOMA standards as updated or explicitly cites the 2024 version.
What Changed in BOMA 2024 vs. Prior Standards
BOMA 2024 (BOMA/ANSI Z65.1-2024) introduced several measurement updates relative to the prior 2017 standard. The most significant changes for commercial office and mixed-use properties:
| Area Type | Prior Standard (2017) | BOMA 2024 |
|---|---|---|
| Outdoor amenity areas | Generally excluded from RSF | Included in some measurement methods when used as building amenities (rooftop terraces, plazas) |
| Semi-enclosed structures | Inconsistent treatment across properties | Defined methodology for covered walkways, porte-cocheres, partially open structured parking |
| Void areas (above floors) | Measured per 2017 floor void rules | Updated methodology for atria, double-height spaces |
| Exterior wall measurement | To dominant portion of the exterior wall | Refined definition of dominant portion for complex facade systems |
The most impactful change for reconciliation purposes is the inclusion of outdoor amenity areas. Properties with rooftop terraces, building plazas, and covered walkways may see meaningful increases in measured RSF when remeasured under BOMA 2024.
Impact on Pro-Rata Denominators
The pro-rata denominator — total rentable SF used to calculate each tenant's share of CAM — is the mechanical link between BOMA 2024 and your CAM reconciliation. If a property is remeasured and the total RSF increases, each tenant's pro-rata percentage decreases (assuming fixed tenant SF), which reduces their CAM obligation.
Worked Example — 200,000 RSF Suburban Office Remeasured Under BOMA 2024
| Measurement | Prior Standard | BOMA 2024 |
|---|---|---|
| Building RSF (denominator) | 200,000 SF | 205,000 SF |
| New rooftop terrace (added) | 0 SF | 5,000 SF |
| Tenant A leased SF | 20,000 SF | 20,000 SF (unchanged) |
| Tenant A pro-rata % | 10.000% | 9.756% (20,000 ÷ 205,000) |
| Tenant A CAM share ($500K pool) | $50,000 | $48,780 (savings: $1,220/year) |
A 2.5% increase in the denominator reduces each tenant's obligation by approximately 2.4%. On a $500,000 CAM pool, this is roughly $12,200 transferred from tenants to the landlord collectively.
When BOMA 2024 Applies to Existing Leases
BOMA 2024 does not automatically apply to existing leases. The lease controls which measurement standard governs the rentable area. Three scenarios:
Scenario 1: Lease references "BOMA standards as updated"
The lease adopts BOMA 2024 automatically when the new standard is published. The landlord should commission a remeasurement and update the denominator per the new standard. Notify tenants of any denominator change before the next reconciliation.
Scenario 2: Lease references a specific prior version (e.g., "BOMA 2017 Office Standard")
BOMA 2024 does not apply. The denominator is fixed to the prior standard unless the lease is amended. Continue using the 2017-based measurement.
Scenario 3: Lease states a fixed rentable area in square feet with no measurement standard reference
The fixed SF governs. No remeasurement is required or permitted under BOMA 2024. This is the most common structure for older leases and provides the most stability.
Landlord Action Items
For landlords managing buildings with amenity areas or semi-enclosed structures, the BOMA 2024 transition warrants a structured review:
- 1. Audit lease language for BOMA standard references. Review every lease in the building to determine whether it references BOMA standards as updated, a specific version, or uses a fixed area. Categorize leases by measurement standard applicable.
- 2. Commission a BOMA 2024-aligned remeasurement for buildings where the new standard would increase the denominator (beneficial to tenants) and where leases reference updated BOMA standards. Document the methodology.
- 3. Notify affected tenants of any denominator change before applying it to the reconciliation statement. Provide the remeasurement report and explain the impact on their pro-rata share.
- 4. Document methodology in the reconciliation statement. Note that the denominator is "BOMA 2024-aligned where applicable" — not "BOMA 2024 compliant," which implies a formal certification.
What Can Go Wrong
Applying BOMA 2024 to leases that reference a prior standard
Switching to a BOMA 2024 denominator for leases that reference BOMA 2017 or use a fixed rentable area is a unilateral change to the lease. If the denominator increase reduces tenant obligations, tenants may accept it — but the landlord has no right to demand the new denominator without a lease amendment.
Inconsistent denominators across tenants in the same building
Using different denominators for different tenants in the same building (some on BOMA 2017, some on BOMA 2024) creates pro-rata share discrepancies where the shares don't sum to 100% of the building. Maintain a consistent denominator for all tenants in a given reconciliation period.
Claiming "BOMA 2024 compliant" without formal certification
Using "compliant" language creates an implied warranty that the measurement was performed and certified per the full BOMA 2024 standard. Use "BOMA 2024-aligned where applicable" to describe a methodology that follows the new standard without claiming formal certification.
Frequently Asked Questions
Does BOMA 2024 automatically apply to my existing leases?
No. BOMA 2024 applies to an existing lease only if the lease references BOMA standards as updated or explicitly cites the 2024 version. Leases referencing specific prior versions or using fixed rentable areas are not affected.
What types of areas did BOMA 2024 add to measurement?
BOMA 2024 introduced measurement methodology for outdoor amenity areas (rooftop terraces, plazas used as building amenities), semi-enclosed structures (covered walkways, some structured parking), and updated void floor and exterior wall measurement rules.
If BOMA 2024 increases the building's RSF, does each tenant's pro-rata share go down?
Yes. If the denominator increases and the tenant's leased SF is fixed, their pro-rata percentage decreases — which means they pay a smaller share of the same expense pool. This is generally beneficial to tenants.
What does "BOMA 2024-aligned where applicable" mean?
It indicates that the measurement methodology follows BOMA 2024 where the new standard applies, without claiming formal certification. This is the recommended language for reconciliation statements — avoid "BOMA 2024 compliant," which implies certification.
Related Resources
BOMA 2024 Outdoor Areas and CAM
Deep dive into how rooftop terraces and plazas are measured and affect CAM denominators.
Pro-Rata Denominator Explained
What goes into the denominator and how to validate it against your lease.
Pro-Rata Share Validation
Validate that all pro-rata shares in a building sum correctly and match lease terms.
BOMA 2024 Standard Overview
Full overview of BOMA/ANSI Z65.1-2024 measurement methodology.
Validate Your Pro-Rata Denominators Against BOMA 2024
CapVeri checks that your building denominators are consistent, correctly applied across all tenants, and documented — reducing measurement disputes before they become CAM audit findings.
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