The paper buildings for Dropzone Commander are an inexpensive way to get scenery on the table. But, when you fold and unfold them all the time, you end up with buildings that aren't square. And they are easily moved around on the table.
These building sidewalks ensure the building corners are square and add a little more weight to the buildings to help stop them from moving. Or you can sneak a little BluTak on the bottom to hold them better in place.

This is an improved version of my earlier building corner. Printing four corners separately and attaching to the buildings got rather fiddly. Now you just need to fit the bottom of the building in the slot.
This is a customizer. Standard building sizes are: 71mm x 109mm, 109mm x 109mm and 109mm x 180mm.