When putting a building together, we normally start by adding a small piece of balsa wood to the back edges of the buildings side pieces. This serves to make the corners of the building stronger and provides a larger surface area for glue sticking the pieces together.
The glue we use for our buildings is UHU, although any similar contact adhesive will work just as well. The main consideration is that once it has set, the glue should be slightly flexible, so the building will not be brittle – unlike superglue or epoxy glue.
A hot glue gun can be used if desired.
Apply glue to one end of a building side section and attach it to one of the building end pieces.
Repeat this with the other side section, so you end up with a “U” shape.
Now glue the other end piece and attach it to the two side pieces.
Once the glue has set, you should have a rectangular shaped building, and at this point you have two choices.
You can either attach a base to the building (made of mountboard, card, etc) and leave the roof separate to allow you to put troops inside during a game, or you can leave a base off and permentantly attach the roof.