If you want to use hot sugar candy then make a royal icing frame and dry it completely. Or a cookie frame (I suspect you are thinking of the stained glass cookies that have candy that melts in the oven).
Pouring candy precisely takes LOTS and LOTS of practise as well as a design with few corners. Pipe the outlines with royal icing onto sheets of gelatin, and use piping gel which does slowly crust, and you will neither burn yourself nor waste your time. These windows will stand up or can be glued into standing buildings if necessary.
If you want to use candy, then make sheets of that for your base instead of gelatin. But you MUST keep the pieces in a dessicator to make sure they don't start leaking when they absorb humidity.