Three Numbers to Review Before You Underwrite a Small Commercial Asset

Small commercial listings come with a polished summary page, and the polish is exactly why I do not trust the summary. Before I spend weeks on a deal, I check three numbers that tell me whether it deserves the time.

Number One: The Real Net Operating Income

Net operating income, or NOI, is the property's income after operating expenses and before debt payments. The seller's NOI is a claim. Your NOI is something you build.

Ask for the trailing financials and compare them to the leases and bank deposits, not just the summary. Then look for the usual distortions:

• Expenses that are missing or understated, such as management, repairs, or reserves that the owner does not pay because they handle things personally.
• Income that is not collected, including rent that is billed but unpaid.
• Reimbursements that look generous in the summary but do not match what the leases actually allow.
• Property tax that has not been reset for a new purchase. California property tax is commonly figured at about 1.1% of the purchase price, so a buyer's bill can differ sharply from the seller's. Verify the figure for the specific parcel.

If the NOI changes materially after you clean it up, everything built on top of it changes too, including the value you are willing to pay.

Number Two: A Vacancy Figure You Believe

Every commercial property has vacancy at some point. The question is how much you assume and how you treat space that is empty today.

For a property that is fully leased, do not underwrite zero vacancy. A tenant will eventually leave, and the unit will take time and money to re-lease. For a property with empty space, price it as vacant until a signed lease says otherwise, and add the cost of leasing it up, including commissions and any improvements a new tenant will expect.

I like to see a cautious vacancy assumption set before I look at the asking price, so the number does not bend to fit the deal.

Number Three: Lease Rollover Timing

This is the number most new investors skip. Two properties can show the same NOI today and carry very different risk. If most of the leases expire in the same window, your income can drop at once. If expirations are spread out, a single departure hurts less.

Make a simple table with each tenant, lease end date, renewal options, and the current rent compared with what you believe the market supports. That table tells you where the risk and the opportunity are. Do not assume market rents without checking comparable leases yourself.

Where Your Cap Rate Fits

A capitalization rate is NOI divided by price, and it is only as reliable as the NOI behind it. As an example archetype, I have worked with a multi-tenant retail plaza targeted around a 6.2% cap rate, but that figure is an illustration and not a promise of what any property will deliver. Cap rates vary by asset type, location, and lease quality, so verify current market ranges rather than relying on a headline.

How We Structure the Work

KC Investment Corp handles commercial and investor acquisitions, including lease due diligence and structuring. Because our brokerage, our in-house KC Mortgage Desk, and Socal Trusted Escrow operate as one unified fiduciary model, you are not waiting on three unrelated companies to answer the same questions. We coordinate toward a 14 to 21 day close, compared with the 30 to 45 days common with outside escrow, though every file is different.

Next Step

If you want a checklist to run these three numbers on your own, use the Download 2026 Playbook button on this page. It will give you a starting framework, and we can talk through the results whenever you are ready.

Educational information only; not legal, tax, or lending advice. Consult a CPA, attorney, or lender about your situation. Rates, programs, and rules change.

Charles Nguyen, Licensed Broker, DRE #01846114