Commercial deals move slower than home purchases, and that is on purpose. You are not really buying a building. You are buying its income, and you need time to prove that income is real before you commit. The seller's broker hands you a glossy packet of numbers called an Offering Memorandum, or OM. Treat it as a sales pitch, not the truth. Almost everything that goes wrong in a commercial purchase traces back to a buyer who accepted those numbers without testing them. Here is the whole process, and how to keep the upper hand at each step.

Decide what you're actually buying for

Before you look at a single listing, get clear on your goal, because it changes which buildings make sense. Are you buying for steady monthly income, for the building to grow in value over time, or for a place to run your own business? A small strip of shops and a mixed-use building next to a train station can have the same price and behave like completely different investments.

Buyers who skip this step end up chasing whatever looks exciting instead of judging each deal against a clear target. In most markets, the steadiest commercial properties are buildings with several tenants on long leases, well-located mixed-use near transit, and older offices being converted into apartments. Knowing your goal lets you say no quickly and focus your time where it counts.

Never trust the seller's numbers — prove them

The income in an OM is often "pro forma," which is a polite way of saying projected or best-case, not what the building earns today. Your job is to replace those hopeful numbers with real ones before you offer. Ask for documents that show actual performance, not predictions:

  • The last 12 months of actual rent collected, tenant by tenant (the "rent roll").
  • A history of empty units and how long they sat vacant.
  • Two to three years of real operating expenses: taxes, insurance, repairs, management.

Know your one key number: NOI

The single number that drives a commercial price is Net Operating Income, or NOI. It is simple: all the rent the building actually collects in a year, minus all the costs of running it (but before the mortgage). That is the building's true yearly profit.

Price is usually set by dividing NOI by a percentage called the cap rate. A building with $100,000 of NOI at a 6% cap rate is worth about $1.67 million. The trap is obvious once you see it: if the seller pads the income or hides expenses, the NOI looks bigger and the price looks justified. Calculate NOI from the real documents you gathered, never from the OM's projection.

Use the early offer to buy yourself room

Your first offer is usually a Letter of Intent, or LOI. It is not yet a binding contract; it sets the price and terms you'll negotiate in detail later. Here is the mistake to avoid: if you offer close to the asking price based on the OM, you have quietly agreed those numbers are right, and you lose leverage later.

Instead, use the LOI stage to start digging. Find the soft spots in the seller's claims, and make sure the LOI gives you a real inspection window, called the due diligence period. For anything over $1 million, ask for at least 30 days. That time is your protection, and it is also your negotiating room.

Budget time for inspections and an environmental check

Commercial buildings need two kinds of inspection, and both can change the deal. A Property Condition Assessment looks at the physical building: the roof's remaining life, the heating and cooling, and whether it meets accessibility rules. None of these are automatic deal-killers. They are reasons to ask for a lower price.

The second check is environmental. Lenders almost always require a Phase I review, which studies the property's history for pollution risk. If the site once held something like a gas station or dry cleaner, you may need a Phase II, which tests the soil and can take weeks. Build that time into your schedule so it does not blow your deadline.

Plan for slower, stricter financing

Commercial loans do not close in 30 days. A short-term "bridge" loan can close in roughly 20 to 45 days but costs more in interest. Standard loans for apartment buildings often take 45 to 75 days. Line up your lender early so financing is not the thing that kills your deadline.

Lenders also test whether the income covers the loan. They look at a ratio called DSCR (debt service coverage). A DSCR of 1.20 means the building earns 20% more than the mortgage payment, a common minimum. If you are buying a half-empty building to fix up, the current income may not clear that bar, so you may need a bridge loan first or to take over the seller's existing loan.