As alluded to under Scale, the base may be constrained to fit onto a display shelf. Once the size is established, it can be filled with a pattern such as grass or snow or dirt. It can even have elaborate elements such as hedges, flowering plants, brick or dirt paths that line up with doors, etc. As a design assistant, make a non-cutting shape that corresponds to the footprint of the building (plus any prominent elements). Fill it with a grey and make it transparent so that it barely shows. Then place that on the base where the building will ultimately be mounted. You can also put a 1.6 inch cut circle in the middle of the building footprint so that the base will be cut to allow insertion of an LED tea light.