When you call the department of buildings, try to have all your information needed. You will need, address and block and lot numbers. This is all public information and you should be able to find it by looking it up on the tax records.
From all the years I've sold real estate on Staten Island, I know that the dept of buildings is very strict on their approvals, and would easily give anyone who isn't within the guidlines a violation.
If a home is built without being in comforming with the code, they will not be able to obtain a certificate of occupancy (c of o). Without a c of o, I don't know if that home could ever be sold.
here is a site that may be helpful to you. http://a810-bisweb.nyc.gov/bisweb/bispi00.jsp
Cathy Cataletto 917-829-1402
Licensed Real Estate Salesperson
Serviing Staten Island & New Jersey