Good idea!....Architects have been mocking up structures for clients using foamcore board for years.
Some comments to add to the above responses...
Similar to Rich's idea of laminating Plastruct to the foamcore shell, I've seen several nice 'temporary' structures on layouts done using printed paper....wall textures/materials, windows, doors, etc., etc....laminated to the shell with spray adhesive (NOT white glue....which will induce warpage). Evans Design, Clever, et al, have structural design programs for your computer which can be printed, cut out, and laminated.
Gatorboard is a nice, non-warping structural material, but it's not that easy to work. The wood composite outer layers are not easily cut using a hobby knife...a saw is pretty much necessary.
MicroMark is also selling a new material called TaskBoard..."The Architects' Choice"...which carries this description: "Taskboard is an ultra-lightweight, rigid wood-fiberboard that's easy to cut with a knife and especially good to cut with a laser. Cut edges are smooth and require minimal sanding. Taskboard comes in a flat sheet, but the 1/32 inch and 1/16 inch thicknesses can be easily formed into 3D shapes . . . just spray with water, form to shape and hold until dry. The white Taskboard has a finish that readily accepts glue and paint." We (LHS) have just started to carry it, have not tried it ourselves, but it appears to be a nicely improved compromise to foamcore and Gatorboard. (Available sheet size may be an issue for some projects, however.)
Re painting foamcore.... I've personally found that inducing warpage to the shell material can be minimized if the paint is applied thinly (sprayed, preferably) with each coat immediately dried with a pistol-type hairdryer. (I made a 'holster' for my dryer, attached it to the side of the spray booth.) And, of course, solvent based paints should induce less warping, regardless, than acrylics (water-based).
Finally, foamcore pieces glued at 90-degrees to the backside of walls, or complete interior walls, can be used to reinforce outer walls against warpage. Of course scrap, sturdy stripwood will also work for reinforcement, too.
I've seen some pretty 'incredibly credible' structures using foamcore. Some of those so-called mock-ups are worthy of permanence.......IMHO.
"Lucas Gudinov"
