I stuck to a pretty simple method of using foam-core and wood glue, pinning as I glue and removing the pins once dry. I picked up a set of dressmaking pins for making LARP costumes and have honestly found as much, if not more, use making foam-core buildings. I suspect using expanded polystyrene or solid foam insulation might have been quicker, but once I'd started, I deceided to finish it that way.
|Walls shown in situ. 40mm based miniature for scale.|
I kept the height of the walls to 50mm, with an additional 5mm top. sat on the same surface as the cork tiles, so total actual height ended up around 53mm. Just high enough above the height of a standard model to feel like a wall but not too high so I couldn't get my fingers in to move them around.