Renting out 2nd floor of a one family house (apartments, to rent)

[columbia323]

An aging family member owns a large 1 family home with 2 floors in Staten Island. His kids have moved out and he's heading into the retirement stage in is life. He has no need for so much space and wants to rent out the 2nd floor of his house for some fixed income. I am trying to help him understand the legality of doing this.

All the necessary kitchen hooks ups are there on the 2nd floor. He plans to install a stove and a fridge. The bathroom is already a 3/4 shower. He has a full kitchen on the first floor already. Currently there is one meter for gas and electricity. I asked him about conversion to a 2 family, but he said it might not be possible because of the updated parking restrictions. Something about 2 driveways and he only has one.

Unfortunately most of the search results I found pertain to basement apartments and I didn't see any that pertain to renting out the 2nd floor of a single family home.

Would the experts here be able to comment on the legality of this situation (preferbly with some citations)? From the basement research, I noted that you are legally able to rent out a basement of a one family home if certain requirements are met. If a basement can be rented out, a 2nd floor shouldn't be an issue right?

[yodel]

He should get the house changed legally to a 2 family, and if not, just rent out a room rather than the entire apartment, without adding an illegal kitchen, etc. It sounds like too much of a headache with potential legal problems. It's very easy for someone to find out that the house is only single family, and then he would be behind the 8 ball.

[nightcrawler]

sell the house and buy a one bedroom condo.
who needs tenant headaches in retirement age.

[macnyc2003]

He needs to be in an area that is zoned for two-family homes. Otherwise it's not possible to add an apartment legally.

[columbia323]

Spoke let him know what I found out and suggested he consult a lawyer also . He's pretty stubborn though. He explained that his house was orignally a two family and he converted it to a one family to save on taxes many years ago. Now zoning rules have changed and he can't convert back. However, he's adament about renting it out.

Am I correct in understanding that if he rents out the rooms individually and does not install the stove, then it is legal?