Here is the full-sized mockup of the garden railway craft shop. I have a lot of scrap foamcore, so why not?
Here are the template pieces taped to the insulation foam. Plenty of leftover foam from this 2' x 2' square.
I went to S.C.R.A.P. today. I took along a piece of foamcore with the dimensions of the doors, windows, roof pieces, etc. By measuring various bits and bobs against this, I found that some lids to some tea canisters were exactly the right size for the window boxes.
I cut them with the Dremel tool, then inserted them in slots in the mockup.