I have modified some to make simple 40mm houses.
I make 2 sides and half the roof, print 2 copies and build the house.
Print at about 90% of file size : check with a test print to make door 40mm high.
Paste the paper copy to card or print on card.
The building needs stifffeners or use thick board/card.
Make a ruin which has the same base area and the house can slot over this.