Last year (2003) I began construction on a number of 20mm scale buildings for FMAS games. This was the second building I put together.
The building is made out of corrugated cardboard with thin cardboard used for the doors and side roof. I drew the outline out on the cardboard first, laying out where the windows and doors would be. The side shed was a part of the front panel, but was made up of separate pieces in the back. I used toothpicks to pin the back wall of the shed to the side wall.
For the doors I cut out the front part of the corrugation leaving the thin card backing and then glued an additional piece of cardboard in the hole. The big garage door was scored to simulate the panels that real doors have so they can fold as they roll into the ceiling.
Once the walls were cut out and glued, I covered the walls with a plaster/water/glue mixture. Once that was dry I gave it a base coat with black spray-paint and then painted the walls a red brick color. The roofs and extra bits were painted a dark gray.
The chimney was from an old train set, the other "bump" on the roof is a small capacitor, and the "A/C" unit on the back of the shed is another, larger capacitor.