How much does it cost to convert single family to two?

[Syed Almamun]

How much does it cost to convert single family to 2 family in nyc? What are the process?

[Ned Carey]

@Syed Almamun that is almost like asking  how much does it cost to fix a car. It depends on so many things. What is the layout of the property now? How old and what condition are the systems? What level of cosmetics are you going to renovate to? how hard will it be to get plumbing to the new kitchen and any new baths needed.

I can't imagine $15k coming anywhere close to being enough. 

Keep in mind an important factor is whether zoning even allows the conversion.