Commercial Real Estate Terms Every Business Owner Should Know

Commercial real estate has its own vocabulary, and unfamiliar terms can make a lease or purchase feel more complicated than it needs to be. Understanding a few common concepts can help business owners compare properties, ask better questions and make informed decisions.

Base Rent

Base rent is the starting rental charge for the premises. It may be quoted as a dollar amount per square foot per year. For example, a rate of $18.00 per square foot on 2,000 square feet equals $36,000 per year, or $3,000 per month, before any additional expenses.

Triple Net Lease (NNN)

In a triple net lease, the tenant pays base rent plus its share of certain property expenses, commonly real estate taxes, building insurance, utilities, and common area maintenance. Estimates may be reconciled against actual expenses, so the amount can change from year to year.

Full-Service and Modified Gross Leases

In a full-service lease, many operating expenses are included in the quoted rent, although exclusions or expense increases may still apply. In a full-service lease, a Base Year may apply. A modified gross lease divides expenses between the landlord and tenant in a way defined by the lease. Because structures vary, compare total occupancy cost rather than the quoted rate alone.

Common Area Maintenance (CAM)

CAM generally refers to costs associated with maintaining shared portions of a property. Depending on the lease, this might include parking lot care, landscaping, snow removal, common utilities, repairs and management. The definition and permitted charges should be reviewed carefully.

Usable and Rentable Square Feet

Usable square feet generally describes the area a tenant occupies directly. Rentable square feet may include a proportionate share of common areas such as corridors or lobbies. The method used can affect the amount of rent, so confirm which measurement appears in the proposal.

Letter of Intent (LOI)

An LOI summarizes the proposed business terms of a transaction, such as rent, lease length, improvements and timing. It is commonly used as a roadmap for drafting the lease or purchase agreement. Whether any provision is binding depends on the document’s language, so it should be reviewed carefully.

Tenant Improvement Allowance (TIA)

A tenant improvement allowance is an amount a landlord agrees to contribute toward approved improvements to the premises. The lease should address qualifying costs, approvals, payment timing and what happens to unused funds.

Due Diligence

Due diligence is the period in which a buyer investigates a property before completing a purchase. Reviews may include physical condition, environmental matters, title, survey, zoning, leases, operating information and financing.

Option to Renew

An option to renew gives a tenant the right to extend the lease if specified conditions are met. The option may establish rent in advance or provide a method for determining it. Notice deadlines are especially important.

Assignment and Sublease

An assignment generally transfers the tenant’s lease interest to another party, while a sublease allows another occupant to use some or all of the space under the original tenant. Landlord consent and continuing tenant liability may apply.

Cap Rate

A capitalization rate, or cap rate, is one measure used to compare income-producing properties. It is generally calculated by dividing a property’s net operating income by its value or purchase price. It does not capture every factor affecting an investment.

Start With the Full Picture

Definitions can vary from one document to another. Before making a decision, review how each term is used in the actual lease, proposal or purchase agreement.

NAI FMA Realty helps Lincoln-area owners, investors and businesses navigate commercial real estate with clear market information and experienced guidance. Attorneys, accountants and other specialists should advise on legal and financial matters.

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Posted October 17, 2026