This is years late but somone might benefit.
For about ten years I made 5 or 10 houses a year from a recipe in a late 1960 Family Circle that produces 5 houses per recipe, walls and decorations of gingerbread, roof and base of cardboard. The most difficult part was rolling and cutting all those tiny cookies. Several years my Girl Scout troop did the assembly and decorating. They loved it and the pictures of frosting coated girls are great! The "mortar" and cookie "paint" is simply a thick paste of water and confectioners sugar. It was easy to work with because it does not dry too fast and can be thinned as needed for using on different areas. You use cans from your pantry to hold the walls while they set. Tomato sauce cans fit well on the inside or a lg can of fruit. soup cans did the outside well. As years went by I gathered quite a co;;ection of kids cookie cutters and Aspic cutters but then got to where I make fewer houses, make the roof and base of dough and use animal crackers, tiny pretzels and more candies. for a scout troup I would still opt for cardboard base and roof because the weight works best if donating or transporting. Cover the cardboard with foil and a good quality white paper napkin. Even though I had Girl Scouts for years , I had 3 sons who liked he houses but grew away from them quickly. I now have a granddaughter and am looking forward to making these again with her.