How to Read a Commercial Lease: A Tenant's Guide

1. Why commercial leases are written the way they are

Commercial leases are not like residential leases. There is no standard form, no rent stabilization, and very little statutory protection for tenants. The landlord's attorney drafts the lease, and the starting draft is written entirely in the landlord's favor. Every clause you don't negotiate stays exactly as written.

This is not a complaint about landlords — it's how the market works. Commercial tenants are assumed to be sophisticated business parties who can negotiate on equal footing. Courts generally enforce commercial leases as written, even when the result is harsh.

What this means practically: every provision that seems like boilerplate was put there for a reason. The three most dangerous words in a commercial lease are "standard language" — because standard-for-whom matters enormously.

2. How the document is structured

A commercial lease has two main parts: the lease body and the exhibits. Most tenants read only the body. Many of the terms that matter most are buried in exhibits.

The lease body is organized into numbered articles or sections. A typical structure looks like this:

• Definitions / Basic Lease Terms — the glossary that controls everything else. Often Article 1 or a separate cover page called the "Lease Summary."
• Term / Commencement — when the lease starts, when rent starts, and what happens if the space isn't ready on time.
• Rent — base rent, escalation schedule, and payment mechanics.
• Operating Expenses / CAM — what you pay beyond base rent, how it's calculated, and what the landlord can include.
• Use — what your business is permitted to do in the space, and what is prohibited.
• Maintenance and Repairs — who fixes what when something breaks.
• Alterations and Improvements — what you can build out and whether you have to remove it at lease end.
• Assignment and Subletting — whether you can transfer the lease, and under what conditions the landlord can refuse.
• Default and Remedies — what constitutes a default, the cure period, and what the landlord can do to you.
• Renewal Options / Expansion Rights — your right to stay beyond the initial term, and at what rent.
• Miscellaneous / General Provisions — notice requirements, governing law, arbitration, personal guarantee, and other provisions lawyers call "boilerplate" (it isn't).

The exhibits follow. Common exhibits include: Exhibit A (floor plan and legal description of the premises), Exhibit B (tenant improvement work letter), Exhibit C (rules and regulations), Exhibit D (personal guarantee), and Exhibit E (renewal option terms). The personal guarantee is almost always an exhibit — and it's one of the most important things in the document.

3. Read the definitions section first

The definitions section (sometimes called the "Basic Lease Terms" or "Lease Summary") controls how the rest of the document is read. A term used 40 times in a lease has whatever meaning the definitions section assigns it.

Pay particular attention to these defined terms:

• "Premises" — the actual space you're leasing. Should reference Exhibit A and specify whether the square footage is usable or rentable. If it just says "approximately 3,000 square feet," that's a problem — get the measured number in writing before you sign.
• "Building" — the entire building or complex. Matters because your pro-rata share of operating expenses is calculated as your rentable sq ft divided by total Building square footage. How "Building" is defined determines your denominator.
• "Commencement Date" vs. "Rent Commencement Date" — the lease often starts (you take possession) before rent starts (you begin paying). The gap is called a rent abatement or free rent period. Make sure these are defined separately and the free rent period is clearly stated.
• "Permitted Use" — the specific activities your business can conduct. Read this very carefully. If your business expands or pivots, a restrictive Permitted Use clause can put you in default. See our guide to permitted use clauses for what to negotiate.
• "Operating Expenses" or "Additional Rent" — what counts as a passthrough expense. This definition determines how much your monthly cost can grow beyond base rent. "Operating Expenses" defined broadly can include capital expenditures, management fees, and even landlord profit. See Section 7 below.

4. How to read the rent section

The rent section has more parts than most tenants realize. Here is what to look for in each:

Base rent

Stated as either a total monthly amount or a per-square-foot annual rate. If it's per square foot, make sure you know whether that's per usable or rentable sq ft, and confirm the square footage number is the one you agreed to verbally.

Rent commencement and free rent

The lease should state the exact rent commencement date or the formula to calculate it (e.g., "30 days after landlord delivers possession"). Free rent months should be listed explicitly, not just implied by the commencement date math.

Escalation clause

How rent increases each year. The three common types are fixed percentage (e.g., 3% annually), CPI-indexed, and step-up schedule (year-by-year dollar amounts listed in a table). A step-up schedule is the most tenant-friendly because both parties know the exact number from day one. CPI-indexed without a cap is the most dangerous. See Section 6 for the compounding math.

Late charges and interest

Most leases include a late charge (typically 3–5% of the overdue amount) after a grace period (usually 3–5 days). Some also charge interest on late rent at an annual rate. Check that the grace period is at least 5 days and the late charge is a flat fee, not compounding interest.

Additional rent

Many leases define all tenant obligations (CAM charges, taxes, insurance, holdover rent, late charges) as "Additional Rent." This matters because defaults on Additional Rent trigger the same remedies as defaults on base rent — including the landlord's right to terminate.

5. Usable vs. rentable square footage

This is one of the most misunderstood cost drivers in commercial leasing. You pay rent on rentable square footage, which is larger than the usable square footage you actually occupy.

• Usable square footage (USF) is the space inside your demised premises — your four walls. This is what you and your team physically use.
• Rentable square footage (RSF) adds your pro-rata share of building common areas: lobbies, corridors, restrooms, mechanical rooms, and sometimes exterior walls. This is what you pay rent on.

The difference is called the load factor (or add-on factor). It is typically 10–25% in office buildings and 5–10% in industrial or retail.

Always ask for both the usable and rentable square footage in writing. Calculate the implied load factor yourself. A 25% load factor on a multi-year lease can add tens of thousands of dollars to your total cost relative to what the headline number suggests.

If the lease says only "approximately 2,500 rentable square feet," ask for a remeasurement before signing. Landlords sometimes overstate rentable square footage, and the error compounds over the full lease term.

6. How escalation clauses compound

Most tenants look at the Year 1 rent and miss the compounding effect of annual increases. Even modest escalation rates add up significantly over a 5 to 10-year lease.

CPI escalations without a cap are riskier. In 2021–2022, U.S. CPI hit 8–9%. An uncapped CPI clause signed during a low-inflation period can trigger rent increases 2–3x higher than the tenant anticipated. The cap negotiation is simple: ask for "CPI, not to exceed 3% per year." Most landlords accept this.

The best tool to model your specific lease is the LeaseLens Lease Cost Calculator — enter your base rent, escalation rate, and CAM charges and it generates a year-by-year breakdown for the full term.

7. Operating expenses and CAM charges

In a NNN or modified gross lease, you pay base rent plus a pro-rata share of operating expenses. This is where tenants most often get surprised — because the operating expense section is long, densely written, and almost always in the landlord's favor.

The four things to check in the operating expense section:

1. What is included in "Operating Expenses"

A broad definition can include property management fees (5–10% of collected rents), capital improvements ("amortized capital expenditures" is a common phrase), HVAC replacement, and landlord administrative costs. Narrow it to: property taxes, building insurance, routine maintenance, and common area utilities. Capital expenditures — roof replacement, elevator modernization, structural repairs — should be excluded or capped. See our complete CAM charges guide.

2. Whether CAM is capped

An annual increase cap on the controllable portion of CAM (5–8% is common) protects you from runaway expense growth. Uncapped CAM in a property that ages badly can grow 15–20% in a single year. Push for a cap on controllable expenses; property taxes and insurance are typically excluded from caps because the landlord can't control them.

3. Gross-up provisions

If the building is not fully occupied, landlords sometimes "gross up" variable operating expenses to what they would be at full occupancy (typically 90–95%). This is standard for expenses that actually scale with occupancy. It becomes a problem when landlords gross up fixed expenses or use an occupancy assumption higher than actual occupancy.

4. Audit rights

Commercial tenants who audit CAM reconciliation statements find overcharges in roughly 60–80% of audits (per industry surveys). Your lease should give you the right to audit the landlord's operating expense records within 12 months of receiving each annual reconciliation. If the landlord resists audit rights, that is a significant red flag.

8. Critical dates and notice deadlines

Commercial leases are full of notice deadlines — windows during which you must act in writing or forfeit a right forever. Missing one can cost you a renewal option, a termination right, or put you in holdover.

The dates to extract from any lease and put in your calendar on day one:

• Lease commencement and rent commencement dates — when possession begins vs. when rent starts. If these are formula-based ("the later of [X] or the date landlord delivers possession"), calculate the actual dates and write them down.
• Renewal option notice deadline — typically 6 to 12 months before expiration. Miss this and the option is gone. Read our renewal options guide for the full picture.
• Early termination notice deadline — if the lease has an early termination right, the notice window is usually 6 to 12 months before the earliest termination date, with a termination fee. Miss the window and the right lapses.
• Expansion or right of first refusal notice — these often expire 5 to 15 business days after the landlord's notification. Short windows that are easy to miss if you're not watching.
• CAM reconciliation objection deadline — most leases require you to object to CAM charges within 60 to 90 days of receiving the annual reconciliation. After that deadline, the charges are deemed accepted.

9. What landlord remedies actually mean

The Default and Remedies section is one of the most important in the lease and one of the least read by tenants. This is where the landlord specifies what they can do to you if you miss a payment or breach any obligation.

Standard landlord remedies in a commercial lease include:

• Termination and re-entry — the landlord can terminate the lease and retake physical possession of the space after providing notice and a cure period. This is standard and relatively fair if the cure period is reasonable (5–10 days for monetary defaults, 30 days for non-monetary).
• Acceleration of rent — the landlord can declare all remaining rent for the full lease term immediately due and payable. On a 5-year lease with 3 years remaining, this can produce a judgment for hundreds of thousands of dollars in a single lawsuit. Negotiate a mitigation requirement — the landlord must make reasonable efforts to re-lease the space and credit any new rent received against your liability.
• Security deposit forfeiture — the landlord applies the deposit to outstanding obligations. This is expected. The issue is whether the deposit is returned within a stated time period after expiration, with written accounting of any deductions.
• Personal guarantee enforcement — if the lease includes a personal guarantee (typically as Exhibit D), the landlord can pursue the guarantor personally for all obligations. See our personal guarantee guide — the structure matters enormously.
• Attorneys' fees — most commercial leases allow the prevailing party to recover attorneys' fees in a dispute. In practice, tenants almost always pay both sides' fees if they lose a landlord-initiated default proceeding.

10. Exhibits and addenda

Exhibits are legally part of the lease. They are not summaries or supplements — they can modify, override, or add to the main body. Read every exhibit as carefully as the body of the lease.

Common exhibits and what to look for in each:

• Exhibit A (floor plan / premises description) — verify the square footage, unit number, and floor match what you agreed to. Check whether the plan identifies any shared spaces (like a shared mechanical room or hallway) that are included in your "Premises."
• Exhibit B (work letter / tenant improvements) — this exhibit governs how much the landlord will contribute to your build-out, the construction timeline, and who owns the improvements at lease end. Key question: do you have to remove your improvements (and at your cost) when you leave? Many work letters say yes.
• Exhibit C (rules and regulations) — operational restrictions like delivery hours, signage rules, HVAC usage hours, and parking limits. Some rules significantly affect how you run your business. Read for anything that conflicts with your operations.
• Exhibit D (personal guarantee) — if present, this is one of the most consequential documents in the package. Read our personal guarantee guide before signing anything in this exhibit.
• Addenda or letter agreements — any modifications to the printed lease that were negotiated separately. These are often handwritten or separately typed. They control over the preprinted lease form where there is a conflict, which is why landlords sometimes put unfavorable concessions they verbally agreed to in a side letter that "amends" only what is explicitly listed.

11. Red flags to spot on a first read-through

These are the clauses worth stopping on during your first read. If you see any of them, flag for attorney review before proceeding.

1. 1

   Uncapped CPI escalation

   Any escalation clause tied to CPI without a stated annual cap. Add "not to exceed [X]% in any lease year" before signing.

2. 2

   "Landlord sole discretion" language

   Phrases like "in Landlord's sole and absolute discretion" in the subletting, assignment, or alteration sections give the landlord veto power with no standard to meet. Negotiate for "not to be unreasonably withheld, conditioned, or delayed."

3. 3

   Uncapped CAM / operating expenses

   No annual increase cap on controllable operating expenses. Negotiate a 5% cap on controllables; exclude capital expenditures, management fee percentage increases above [X]%, and non-recurring costs.

4. 4

   Holdover at 150–200%

   Holdover provisions above 150% with no cure period are aggressive. Negotiate a 30-day grace period and 150% maximum. See our full guide on holdover clauses.

5. 5

   Full-term personal guarantee

   A PG that runs the full lease term with no burn-off provision creates unlimited personal liability for the full duration. Push for a burn-off (e.g., PG reduces by 20% per year) or a dollar cap.

6. 6

   Consequential damages clause

   Language making you liable for all damages the landlord suffers, including losses from incoming tenants who could not move in on schedule. These can far exceed any rent acceleration.

7. 7

   "As is" condition without defined exceptions

   "Tenant accepts the Premises in their current condition, AS IS, WHERE IS, WITH ALL FAULTS." Without an exception for pre-existing building systems defects, you inherit every problem the space has on day one.

8. 8

   No landlord mitigation obligation

   After a default, the landlord should be required to make reasonable efforts to re-let the space and credit any new rent against your liability. Without this, you pay for the space while it sits empty.

For a structured review of all these issues, paste any clause into the free clause checker. For a full lease analysis covering every section, the $75 LeaseLens report produces a PDF with risk ratings and negotiation priorities for the whole document.

Frequently asked questions