"Is this a good deal?" is a feeling. Seven numbers are an answer. Pull up the listing and the seller's T-12, then fill each check. It grades itself and adds to your score as you go. Fail three or more and you're out.
Why it matters: Cap rate is the deal's price tag in plain English. Well below the submarket means you're paying a premium the income doesn't justify, and you'll feel it the day you sell.
Why it matters: This is the whole game. In commercial, the bank evaluates the asset, not you, and DSCR is how it does it. Clear 1.25x and the deal qualifies on its own income, whatever your credit score says.
Why it matters: Brokers sell the proforma (the dream). You're buying the T-12 (the real version). The gap between them is exactly where investors overpay, so underwrite the actuals.
Why it matters: The safest money in commercial is closing a believable rent gap. A small, provable gap is the cleanest forced value. A gap you have to invent is how good-looking deals quietly lose money.
Why it matters: A suspiciously low expense ratio is the most common way a proforma lies. Understate expenses → overstate NOI → the cap rate looks better than it is → you overpay.
Why it matters: Most of the return in a lot of deals hides in the exit assumption. Shave the optimism and you find out fast whether you're buying cashflow or a bet. Cap-rate expansion is what wipes out investors who only modeled the upside.
Why it matters: Everything else tells you what the deal does when it goes right. This tells you what happens when it goes wrong, and deals are won or lost on the downside. A fat buffer is what lets you sleep at night.