Base year vs. expense stop in office leases, explained

01 / 08

Why office leases use a baseline

A gross rent quoted at the start of a lease has the building’s taxes, insurance, utilities, janitorial and maintenance baked in. If those costs rise every year and the rent does not, the landlord absorbs the inflation. A baseline lets the landlord keep the simplicity of one quoted rent while passing later increases to the tenant.

The tenant pays rent plus an additional charge each year equal to its pro-rata share of operating expenses above the baseline. Everything below the baseline stays inside the rent. The only question is how the baseline is set, and that is the difference between a base year and an expense stop.

02 / 08

A base year: the baseline is an actual year

With a base year, the baseline is the building’s actual operating expenses in a stated year, often the first calendar year of the lease or the year the lease starts. In each later year, the tenant pays its pro-rata share of the amount by which that year’s expenses exceed the base year’s.

The formula is simple: tenant’s increase = (current-year operating expenses − base-year operating expenses) × pro-rata share. A base year follows real numbers, so it adjusts itself to what the building actually cost.

03 / 08

An expense stop: the baseline is a dollar figure

An expense stop sets the baseline as a fixed dollar amount per rentable square foot per year, such as $10.00, negotiated when the lease is signed. The landlord pays expenses up to the stop. The tenant pays its share of the amount above it.

The formula is: tenant’s increase = (current operating expenses per square foot − stop per square foot) × the tenant’s square feet. The stop is usually based on an estimate or the prior year’s costs, but it does not move on its own. Where a base year follows actual data, a stop is a negotiated number.

04 / 08

A worked example

Take a hypothetical 5,000-square-foot suite in a 50,000-square-foot office building, so the tenant’s pro-rata share is 10 percent. In the base year, operating expenses were $500,000, or $10.00 per square foot.

Year 2 expenses are $520,000 ($10.40 per square foot), so the tenant pays 10 percent of the $20,000 increase: $2,000. Year 3 expenses are $560,000 ($11.20), so the tenant pays 10 percent of $60,000: $6,000. Year 4 expenses are $580,000 ($11.60), so the tenant pays 10 percent of $80,000: $8,000.

An expense stop of $10.00 per square foot gives exactly the same answers here, because the stop equals the base year’s cost. The two differ when the stop is set differently. At a stop of $9.50 per square foot, the year 3 charge becomes ($11.20 − $9.50) × 5,000 square feet, or $8,500 instead of $6,000. That $2,500 difference comes entirely from how the baseline was set.

05 / 08

The base-year gross-up trap

A base year is only fair if the baseline reflects a normally occupied building. If the base year is the first year of a new or half-empty building, the variable costs, such as janitorial and utilities, are low because few people are there. Later years cost more simply because the building filled, and the tenant is charged for that growth as if it were inflation.

That is why base-year leases usually gross up the base year’s variable expenses to a stated occupancy, such as 95 percent, the same adjustment explained in the CAM gross-up guide. In the example, suppose $100,000 of the $500,000 base year was variable and the building was 70 percent occupied. Grossing that up to 95 percent makes the base year $535,714. If year 3 is above 95 percent occupied and therefore not grossed up, the tenant’s year 3 increase falls from $6,000 to about $2,429. Without the gross-up clause, that is $3,571 the tenant overpays.

06 / 08

What happens if costs fall

Most leases floor the increase at zero, so if expenses drop below the baseline the tenant pays no additional charge but does not receive a refund of rent. Some leases carry a credit into later years instead. This is a lease term, not a rule, so read the clause before you promise a tenant anything.

07 / 08

What to record for each tenant

The annual calculation is only as good as the baseline on file. For every tenant with a base year or stop, keep the following with the lease, and keep it for the life of the lease, because the baseline never expires. The free calculators on this site do not model base years or stops, so run this in your own worksheet and keep the clause beside it.

08 / 08

Choosing between them as an owner

A base year is more transparent and self-adjusting; a stop is simpler to quote but needs a defensible starting figure. Small office owners commonly use a base year with a gross-up because it adjusts to actual costs and is easy to explain to a tenant. Whichever you choose, define the expenses precisely and keep the baseline documented. This is general information, not legal advice, and the signed lease controls.

Put it into practice

TenantPoint handles this workflow in Commercial lease administration software and CAM reconciliation software. See all TenantPoint solutions or how it compares with other software.