Last updated October 2026
The office lease clauses that cost tenants the most are usually not the base rent. They are the operating expense pass-throughs, the annual escalation, the assignment and sublease language, and the renewal and holdover terms buried in the landlord’s standard form. Each looks small on signing day and compounds over the term. Since 2004, Tenant Advisors has negotiated more than 2,000 office leases for tenants of 3,000 to 50,000 SF, and in the transactions we track and negotiate, the best results come from negotiating the whole lease, not just the rate.
Key Takeaways
- Operating expenses and CAM charges can grow faster than base rent. A clear base year, defined exclusions, and a cap on controllable expenses keep them in check.
- The annual escalation compounds every year of the term, so it often matters more than the starting rate.
- Fixing a stale base year cut one Schaumburg tenant’s net rent 48.8% without a move.
- Reasonable assignment and sublease rights are your exit if the business grows, shrinks, or is sold.
- Renewal options and holdover terms decide how much leverage you have at the end of the lease.
How Do Operating Expenses Quietly Raise Your Rent?
Most suburban Chicago office space is quoted on a gross basis, which means the rent includes the building’s operating expenses and real estate taxes up to a base year. In the North Suburbs, for example, Class A space runs about $36 to $44 per SF gross in the transactions we track and negotiate. After the first year, you pay your share of any increase over that base. If the base year is set when the building is half empty or when taxes are temporarily low, every later year looks like an increase, and you pay for it.
The language that protects you is specific:
- A base year grossed up to reflect a fully occupied building, so variable costs are not artificially low in year one.
- Defined exclusions, such as capital improvements, leasing costs for other tenants, and financing costs.
- A cap on controllable expenses like janitorial, landscaping, and management fees.
- The right to review the landlord’s expense records.
The base year can matter more than the rent. A 12,600 SF professional services tenant in Schaumburg had an outdated base year adding $81,600 a year in taxes and operating expenses on top of base rent. We reset the base year to the current year and kept the original rent schedule in exchange for a term extension, with a 5% cap on controllable expenses. Net rent fell 48.8%, and the tenant saved $104,514 in the first year. Read the full case.
Tenants already in a lease can also ask for an office lease audit.
Why Does the Annual Increase Matter More Than the Starting Rate?
The escalation is applied to the prior year’s rent, so it compounds. That is why we compare offers on total occupancy cost, not the first-year number. A 3.5% annual increase is common in the transactions we track and negotiate. On 10,000 SF starting at $40 per SF gross, it takes the rent to about $54.50 per SF by year 10. At 2.5%, the same 10-year lease would cost about $210,000 less. A landlord can also win back much of a free rent package through a steeper increase.
The terms we review in every lease:
| Lease term | What it controls | What tenants should ask for |
|---|---|---|
| Base year | The starting point for expense pass-throughs | A grossed-up base year and a fair start date |
| Operating expenses and CAM | Your share of building costs beyond base rent | Clear exclusions and a cap on controllable expenses |
| Annual escalation | How fast rent grows each year | A lower fixed increase, judged on total cost over the term |
| Assignment and sublease | Your exit if the business changes | Consent not unreasonably withheld, and no landlord recapture without your agreement |
| Renewal option | Your right to stay at the end of the term | Renewal at market rate with a defined way to set it |
| Holdover | What you pay if you stay past expiration | A modest holdover rate and a short grace period |
| Relocation and restoration | Whether the landlord can move you, and what you must remove at move-out | Limits on relocation and no restoration of standard improvements |
Based on the transactions we track and negotiate as of October 2026. Specific language varies by building and landlord.
What Happens If the Business Outgrows or Shrinks Out of the Space?
The assignment and sublease section decides whether you can hand the space to a buyer of your business, sublet part of it, or bring in a subtenant if you shrink. Watch for recapture rights, which let the landlord take the space back instead of approving your subtenant, and for profit-sharing terms that send most of any sublease gain to the landlord. Our sublease and disposition work starts with this language, which is far easier to negotiate before you sign.
Which Provisions Protect You When the Term Ends?
A renewal option gives you the right to stay, but only if the rent-setting method is defined. Vague language like “fair market rent as determined by landlord” is not much of a right. If a move slips past expiration, a steep holdover rate turns a few extra weeks into an expensive problem.
The best protection is starting early. Leverage builds 12 to 18 months before expiration, and real leverage means being ready, willing and able to move, with real, negotiated options on the table, not just telling the landlord you are looking at the market. Our lease renewal negotiation process is built around keeping that alternative credible.
Can These Terms Be Changed After the Lease Is Signed?
Rarely, and usually only at a renewal or an expansion, when the landlord wants something from you. That is why a full office lease negotiation covers every business term, not just rent, abatement, and the build-out allowance. Tenant-only representation matters here: we have never represented landlords, so there is no dual agency and no conflict about which side of these terms we are on.
If your lease expires in the next 18 months, or you are reviewing a proposal now, contact us for a lease review. Because the landlord pays our fee, there is no cost to tenants.
Frequently Asked Questions
What is a base year in an office lease?
The base year is the year whose operating expenses and real estate taxes are built into a gross rent. In later years, the tenant pays its share of any increase over that base. A base year grossed up to reflect full occupancy keeps the starting point fair.
Can a tenant cap operating expense increases?
Often, yes. Many landlords will agree to cap increases in controllable expenses such as janitorial, landscaping, and management fees. Taxes, insurance, and utilities are usually excluded from the cap, so clear exclusions matter as well.
Why do sublease and assignment rights matter if we plan to stay?
Plans change. A sale of the business, a merger, or a shift to hybrid work can leave you with too much or the wrong space. Consent that cannot be unreasonably withheld, and limits on landlord recapture, give you a way out without paying rent on space you no longer use.
What does a tenant rep cost to negotiate these terms?
There is no cost to tenants. The landlord pays the tenant rep’s fee as part of the transaction, the same way it pays the listing broker.
About the authors: Tom Koelzer and Dave Ven Horst co-founded Tenant Advisors in 2004 and have represented only office tenants ever since, never landlords. The firm has negotiated more than 2,000 office leases across the Northwest Suburbs, O’Hare, the East-West Corridor, the North Suburbs, and the Chicago CBD. Questions about your lease? Contact us or call (847) 778-0296.