Found a house-hack, but the MIL Apt isn't technically permitted

[Kellon Parkinson]

I came across a great property; it's a 5 bed SFH, but the basement is a 2 bed 1 bath MIL apartment.

The current owner has been renting out the basement, and the home is currently for sale with the basement tenants still inside. Upstairs is vacant. 

However, it even says in the listing that the city doesn't recognize the apartment as a legal accessory apartment. So I looked into the zoning ordinance, and the only reason it's not allowed is because the lot needs to be at least 8000 sq. ft. This lot is 7300 sq. ft. 

This house would make an awesome house hack for us. We would live in the basement apartment, and rent out the upstairs.

I'm just concerned about the apartment not technically being approved.

Only the owner of record can request that the city permit the apartment, so I couldn't do anything about it until I own the property.

What would you do?