4/5 TownHouse

You might want to start with searching for property if you haven't found one yet, and doing feasibility study which includes some research of New York city zoning resolution.

There are many factors affect distribution of residential and commercial spaces, such as the zoning district that your building is located, existing use... etc. If you could elaborate on your situation more, I might be able answer your questions.

Here are some links that might be helpful:
http://www.nyc.gov/html/dob/html/home/home.shtml
http://www.nyc.gov/html/dcp/html/zone/zonetext.shtml

Process of design/construction can be simplified like this:
1.Your architect designs and coordinates with engineers.
2.The architect files plans to DOB and obtains construction permit.
3.Contractors bid on this job.
4.The contractor starts construction.
5.City agents inspect the building and issue certificate of occupancy.

It is probably too early to worry about technical issues such as HVAC, utility hookups or construction.

I left out the financial part because I am not an expert in that.

Thats a LOT of Info in those links, so T H A N K S !!!!! Appreciate it much!
. . . . just took a quick look right now, but will investigate further in detail in the a.m.

What type of elaboration on the situation might help some more?

Your original post was quite general, so my suggestion was also limited.

For a project like this, there are a lot factors come into play and some factors don't apply to certain situations.

As for the city regulation, it is not that complicated. It's certainly doable by yourself, but it's time consuming.

Any information helps. For example, if I know the exact location of the building, I will be able to tell you if you can add more floor area or not, and legal use for the space. In addition, if I have more information about the existing building condition, I will be able to suggest a reasonable space planning. Also, if I know how much your construction budget is and what type of apartment (high-end or affordable) you want to have, I can figure out the building size or lot size you are looking for, or the other way around.

As you can see, the more information I have, the more I can help.

P.S. If you don't want to reveal your info in public, you can email me at generative.arch@gmail.com

"Generative arch" it will be, tomorrow . . . . for just the reasons you stated!
Thanks again!

Hey
How are you doing with your project?
Any progress?