First place I go to is your lender HELOC department. 

Some contractors will refuse to work outside the law and some do not mind so much but if you want to work within the law then first thing will be to go down to your local building department and see what the local zoning is for the property in question .

Best thing to do is to go into the city planning department and talk to them.

One person I dealt with busted out one of my car windows and dumped gas all over my car next to the police department.

Where I’m located (in Virginia) the local development department (building/zoning/etc.) handles storm water regulations and enforcement.

The first service they cut is usually the Fire Department.

@Paul Callaway your first step would be to call the city zoning department and ask them.

You may also reserach your local building department that for addressing posible grandfathered in clauses or conditions. 

My recommendation is that you go to the City council planning department and ask to speak with the supervisor.

The fire department arrived and they flooded the kitchen and chopped the walls open.