Not only is air a terrible conductor, but ducts are notoriously leaky and/or installed in unconditioned spaces, which further kills efficiency.

Depending on the value and potential impact on income you could seek the advice of a land use attorney familiar with the jurisdiction but if the city is notoriously hardline on these issues there's nothing you can do. 

@Moises R Cosme Aren't multi-family homes notoriously hard to sell?

City is NOTORIOUS for requiring permits for EVERYTHING.

(note: architects are notoriously optimistic estimators, so this is just a failsafe.)Do you have a local realtor, do they agree with your numbers for selling, and that you're building what the market wants?

FHA mortgage fraud can lead to up to 30 years in prison and $1,000,000 in fines.

While I am sure this is not your intention, to declare that you will be living in the property as your primary when you have no intention of doing so is mortgage fraud, which is a felony punishable by up to 5 years in prison. 

Lots of so called interest but no follow up.Facebook Marketplace and groups webpages get a lot of interest, but most of the groups are garage sell type groups and that is the type of prospective tenants I get, will you drop the rent, will you work with me on the deposit, will you accept no credit check because mine is bad, "you should not count my domestic violence 7 year prison term as a violent felony because I really did not hurt her", will you take less for cash payment and no written contract, can you furnish it so I can list it on AirBNB? 

Most secondary currencies are losing value by the day and, notoriously, the Turkish lira.

That market is notoriously susceptible to broader market/economic fluctuations.