Go see your local building and zoning dept.... you will find them very helpful. With the proper approvals ( or variance if needed ) in hand and making the building safe and conforming for it's new use... Yes you can.
Success! Real Estate â€“ Mikel DeFrancesco
Real Estate in Massachusetts
There have been a series of major court cases in Massachusetts recently, revoking permits that were "approved" by city officials, but ultimately invalidated by the courts. For example, there is reportedly a $10 million dollar, 8000 sq foot home on Cape Cod, in the town of Truro, that has been deemed by the courts as contrary to the zoning ordinance despite completing construction based on issued permits.. Ironically, this is a house right next to Edward Hopper's home -- the famous American painter. Now, the battle is ongoing as to whether it therefore needs to be torn down. There is another house in Marblehead, right next to the ocean, worth close to a million dollars, that has been ordered to be removed. Again, the developer/owner reportedly had received permits originally from the town to build.
Probably, the best move is to check with an attorney with expertise in zoning for Massachusetts and Belmont itself. Sadly, even if a permit is issued, and the work completed, there are legal actions that are permitted in Massachusetts up to six years out, to enforce a zoning violation and possibly have the offending structure removed. And, even beyond that years later if a dispute occurs, and the property is involved in litigation is deemed not legal by zoning, the property owner may have lesser rights to make certain alterations, such as additions.
Perhaps New Jersey is more liberal in its zoning rules, but Massachusetts clearly has certain legal requirements that need to be met, beyond municipal permit approvals.
Belmont does delineate the allowed uses for the various districts, under the table of uses section in the code. This includes single family, two family, other apartment, and mixed use listings for the various districts.
Is the building in the AH district? Or is it in a zone that would allow for mixed use under a special permit(such as two family and a first floor that is a business use)?
Checking with a real estate attorney may be helpful, to see if there are any special situation that could be applied to the property, to allow its use to be expanded.
Simple answer is that if you are in a zoning district that allows for three family dwellings and you meet the zoning and buidling code requirements (or get a special permit) then you can make it into a 3 family dwelling. if you are not in the proper zone you have a better chance of hitting Powerball.