Seller listed it as a duplex, county says single family, kitchen was pulled out in 2016

Your 9 to 12k for the kitchen assumes the rough-in is still good, and a capped supply line tells you nothing about the drain or the vent. Open the floor where the sink was. If the drain was cut and capped below the subfloor you're running new waste line, and depending on the joist layout that's either a Saturday or a permit and a plumber for three days. Also 2016 is recent enough that whoever removed it may have had to sign something. Ask the seller for anything they got from the county, in writing, this week.

The order of calls is planning department first, lender second, contractor third, and the reason is that the second two answers change based on the first.

Zoning permitting two units by right governs what may be built or established on the parcel. It does not by itself establish that this structure is currently approved as two dwelling units. Those are separate records, the zoning district and the certificate of occupancy or permit history for the building. A property can sit in a two-unit district and still be recorded as a single dwelling unit, which is what your assessor card is telling you. Whether reinstating the kitchen creates a legal second unit or an unpermitted one depends on your local code and the process it provides, and that process differs by city and state, so the planning counter with the parcel number is the only source that answers it. If the answer turns on how a specific ordinance applies to your building, that is a land use attorney's question.

On financing, your assumption that this is underwritten as a one unit is probably correct given the county record, and you have already accepted that you qualify without the downstairs rent. That is the right way to structure it. Separately, on one-unit owner-occupied purchases, Fannie Mae's policy taking full effect in March 2026 allows projected accessory dwelling unit income to count toward qualifying income up to 30 percent of total qualifying income. Whether a downstairs space with no kitchen at appraisal time could ever meet that definition is a question for your lender, and you want their answer in an email rather than a phone call.

The assumption doing the most work in your numbers is that 1,150 is collectible from a unit whose legal status you cannot yet describe.

Run it as a single family with a long term guest suite and see if you still want it. 2,240 payment, no rent, against 1,650 you pay now. That's the downside case and it's the case you're actually underwriting, because the 1,150 is contingent on a permit outcome you don't control inside 14 days. If that spread is survivable, proceed. If it isn't, extend or walk. I'd also want the 2016 story in a document rather than from the agent, since "because of the county" usually means a complaint was filed and there's a file number attached to it.