Great project!  I may try to make one.  A 1/2-1 inch or so of cardboard or popsicle sticks could be glued on the bottom for decoration and to strengthen the base of the structure and clear plastic from envelopes could be on one or both sides as windows for light to emit.  You could color it with a marker for tinted windows.  Other items such as a feather or a dried flower could be glued on top.

It would be fun to make themed houses for all the holidays

Would make an adorable Christmas village.