County said three units, the building had four, and a zoning letter closed it
Fourplex, two up two down, 585k, in a first ring suburb where the current zoning only permits two units per lot. The building predates the zoning by about forty years. County property record showed three units. The fourth was a basement unit with its own entrance, its own meter, and a tenant who had been there nine years.
I've spent enough time on lot questions to be nervous about that mismatch, so before I spent money on anything else I ordered a zoning verification letter from the municipality. That process and what the letter actually says varies a lot by city, so ask what form yours issues before you assume it will help you.
The letter came back in 19 days confirming the four unit use as legal nonconforming, with the condition that if the use lapses for more than twelve consecutive months the nonconforming status goes with it. That condition is the whole risk of the building and I would not have known the exact window without the letter.
What nearly killed it was insurance. The carrier my broker started with would not bind four units when the assessor showed three, and the lender's appraiser wanted the discrepancy resolved before delivering the report. Two closing extensions, 14 days total, and the seller was one week from calling it.
Rents at close: 1,100, 1,100, 1,250 for the larger upper, 1,300 for the basement unit which is oddly the nicest. Taxes 7,400. Insurance came in at 4,900 with the second carrier.
What I'd keep: the letter cost 400 dollars and reordered the entire deal. I now know the twelve month clock, which means I will never let all four sit empty through a long renovation, and I have something to hand the next appraiser or buyer.