I worked for the City for 15 years, in a conservation/historic district you cannot replace the old wood windows or doors with new vinyl windows or steel doors. You can replace them with newer thermo windows but they have to be made to replicate the old windows exactly and those cost an arm and a leg along with a left nut. I dont know how many people tried to slip by and say " oh those were already there when I bought the house" line of BS... The building inspectors know, they are not stupid, there is a paper trail on historic houses like you wouldnt believe.
Here in this town you can build anything and they really dont pay alot of attention to it unless you put a ton of flashing lights on it or something to draw attention to it.
The house I am getting in second of 4 on a dead end road each with an acre or more land so its off the main road quite a ways, you would have to be headed back that way or made a wrong turn just to stumble across it accidently, but everything around it is nice, also its elderly folks there.