I live in a owner occupied Duplex in Philadelphia which also has a finished basement which is apartment style but couldn’t be zoned as a third unit.

Some roadblocks of course come in the form of zoning or rezoning, most cities, and even some counties require a piece of land to meet certain requirements such as set back lines, easements, ingress, and egress to the property.

The property is currently residential but zoned for commercial use as well if we choose to stop using it as a rental property.

Our local architects work with the client to design their ideal home, as well as submit the necessary plans to local zoning/permitting.

So we went to get it subdivided into 4 equal lots.The survery district approved 4 , 1200 sqft lots but it did not pass zoning code for RSA-5 district .1.

Legal review (zoning, title, permits, etc)Again this is not everything, but some general things to consider. 

That area is known for flood zones and foundation issues. 

Post gives lots of detail into requirements and zoning restrictions. https://www.biggerpockets.com/...

Hey Kevin, I would think since its on one parcel and is already zones a multifamily, it shouldnt be an issue. 

It's probably a zoning matter rather than a landlord/tenant matter.