Is there any reason you want to build houses so badly? I just placed 100+ words I needed to memorize around the town I live last weekend. Placed stuff at a fast food place, a mall, up and down a road with little shops.
Does it really matter if the walk you take in your head is inside a house (first one above), more of an open structure (second one), or open air (last one)? I mean, what I’m trying to say, why not use existing structures by using Google Maps or Google Earth… something like this: