Hi, I'm trying to find a right style of fast mapmaking for a rpg campaign I have. I have something somewhat decent (not too slow, readable, not too ugly) for lands and city, but as for building I'm stuck and I don't know where to look.

Let's try it with an example (WIP, there's no refinements here at all), done with Photoshop:

Ok so this was done with path/stroke and line tools, copy/cut + selection flip + manual move (like for the south half of the transepts) plus various little things. It's a bitch to keep everything straight (as you can see ) and it takes way too much time. This is something I would have to be able to do in, somewhere around 15 minutes maybe.

So, does anyone have an idea on how to proceed or which tools to use to be able to keep walls straight, angular connections neat, and maybe be able to divide evenly or smartly space (to put column where they should be, and aligned)?