CAM charges -- common area maintenance charges -- are the most litigated, most disputed, and most misunderstood cost component in commercial leasing. Tenants sign leases based on the base rent figure, then discover months into occupancy that their actual monthly payment is substantially higher. Landlords send annual reconciliation statements that are difficult to verify without knowing exactly what the lease allows. Both sides lose money when CAM is poorly understood.
This guide explains how CAM works, what tenants can negotiate, and how to audit landlord charges after the fact.
What CAM Actually Is
In a triple-net or modified gross lease, the landlord incurs costs to maintain and operate the property that benefit all tenants. Rather than building those costs into base rent and absorbing the variability, landlords pass them through to tenants proportionally based on each tenant's share of the total rentable area.
CAM originated as a straightforward concept: tenants should contribute to maintaining the parking lot, landscaping, and lobby because they benefit from those spaces. In practice, CAM definitions in modern commercial leases have expanded well beyond this original scope. What a landlord can charge as CAM in a well-drafted tenant-favorable lease and what a landlord can charge in a poorly-negotiated lease may differ by $3 to $5 per square foot per year.
What Is Typically Included in CAM
The core of any CAM definition covers expenses directly related to operating and maintaining the common areas of the property:
Exterior and grounds. Landscaping and grounds maintenance, parking lot repaving and line painting, parking lot lighting, exterior signage maintenance, snow and ice removal, exterior pest control.
Building systems shared across tenants. Elevators and escalators, HVAC for common corridors and lobbies, common area electrical, fire suppression systems for shared spaces.
Cleaning and security. Janitorial services for lobbies, corridors, restrooms, and other shared areas. Security personnel or security system costs allocated to common areas.
Administrative and management. Property management fees (charged as a percentage of operating expenses or gross revenue), administrative overhead charges, accounting costs related to operating the property.
That last category is where disputes begin. Property management fees and administrative overhead are legitimate operating costs, but they are also the easiest for landlords to inflate. A management fee of 5% of gross revenue is market standard in most property types. Management fees of 8% to 12% with an additional administrative overhead charge on top of the management fee are not.
What Tenants Can Negotiate Out of CAM
Negotiating CAM exclusions is one of the highest-leverage items in a lease negotiation. Dollar for dollar, a well-negotiated CAM exclusion list is worth more to a tenant than a small reduction in base rent. Here is what tenants in strong negotiating positions typically get excluded:
Capital expenditures. Replacement of major building systems -- roof, HVAC, elevators -- should not pass through to tenants as CAM. These are ownership costs. Most institutional landlords accept capital expenditure exclusions, sometimes with a carve-out for amortized capital expenditures that reduce operating costs (i.e., an energy efficiency upgrade that lowers utility bills).
Costs of other tenants' spaces. Any expense related to leasing, fitting out, or managing another tenant's space should be excluded. This includes leasing commissions, tenant improvement costs, and costs to remedy another tenant's lease default.
Landlord administrative costs above a defined cap. Administrative fees stacked on top of management fees are double-charging. The lease should either have a management fee only, or an administrative fee only, with the combined total capped.
Above-market management fees. If the lease allows a management fee charged to an affiliated management company, it should be capped at market rate and verifiable against comparable properties.
Costs covered by insurance. Expenses that should be covered by the property insurance policy should not also pass through as CAM.
Fines, penalties, and legal costs. Any costs the landlord incurs due to its own negligence or legal disputes with other tenants should not be allocated to you.
The Controllable Expense Cap
Even with a well-negotiated exclusion list, CAM charges can grow substantially over a long lease term if there is no limit on annual increases. The controllable expense cap addresses this directly.
A controllable expense cap limits how much CAM can increase year-over-year on the portion of operating expenses that management can control. The standard cap is 3% to 5% per year, compounded. Non-controllable expenses -- typically property taxes and insurance premiums -- are excluded from the cap because landlords have no control over them.
The cap is cumulative in tenant-favorable leases: if CAM increases only 2% in year one, the unused 1% (in a 3% cap) carries over and allows a 4% increase in year two. This prevents landlords from deferring expenses to circumvent the cap.
Without a controllable expense cap, a tenant's CAM exposure has no ceiling. Over a 10-year lease, uncapped controllable CAM growing at 6% annually nearly doubles from commencement to expiration. The same expenses under a 3% annual cap grow by only 34%.
Gross-Up Provisions
Gross-up provisions allow the landlord to calculate operating expenses as if the building were at a defined occupancy level -- typically 90% to 95% -- regardless of actual occupancy. This is one of the most misunderstood provisions in commercial leasing.
The justification for gross-up is legitimate: some operating expenses are fixed regardless of occupancy. Janitorial for shared corridors, property management fees, and exterior lighting cost roughly the same whether the building is 60% or 95% occupied. If the landlord charged tenants their pro-rata share of actual expenses in a half-occupied building, each tenant would bear an artificially large share of fixed costs that will redistribute when the building fills.
The problem arises when gross-up provisions are applied to variable expenses, when the occupancy percentage is set too high, or when the gross-up is used as a mechanism to inflate CAM without actual expense justification. A tenant who is 10% of a building grossed up to 95% occupancy is paying for 10% of a larger expense pool than actual operating costs support.
Standard practice is to accept gross-up provisions capped at 90% to 95% occupancy, applied only to variable operating expenses, with the specific list of gross-up-eligible expenses defined in the lease.
Audit Rights
The right to audit the landlord's CAM expense records is the single most important protection in an NNN lease. Without it, you are accepting the landlord's word that the reconciliation statement is accurate.
Standard audit rights provisions give tenants 12 to 18 months after receiving the annual CAM reconciliation statement to request an audit. The landlord must provide invoices, contracts, and expense records supporting the charges. If the audit reveals an overcharge above a threshold (typically 5%), the landlord pays for the audit.
Exercise audit rights selectively but take them seriously. CAM audits of institutional properties frequently identify overcharges of 5% to 20% of the reconciled amount. A 10% overcharge on $50,000 in annual CAM is $5,000 back in your pocket, typically for 2 to 3 hours of work by a competent lease auditor.
What to Look for in a Lease Abstract
When reviewing a lease abstract for CAM provisions, these are the fields that determine your actual exposure:
- CAM cap percentage. Is there a controllable expense cap, and what is it? Is it cumulative?
- Base year. What year's expenses establish the baseline for expense stop calculations?
- Excluded expenses. Is there a defined exclusion list, and does it cover capital expenditures, management fee overrides, and landlord administrative costs?
- Management fee cap. Is the management fee capped at a stated percentage?
- Gross-up percentage. At what occupancy level are expenses grossed up?
- Audit rights clause. Is there a defined audit right, notice window, and cost-shifting provision?
- Reconciliation deadline. By what date must the landlord deliver the annual statement?
For CAM reconciliation analysis after the lease is signed, CamAudit.io provides specialized tools for verifying landlord calculations and identifying overcharges against your lease's expense definitions. Lease abstraction gives you the contractual baseline; reconciliation audits verify that the charges match it.
A lease abstract that captures these CAM fields in structured data is the starting point for every subsequent negotiation, dispute, and renewal decision. Get the data right at the beginning and the rest of lease administration becomes significantly more tractable.