There are some interesting houses in Loudonville, NY, just South of Osborne Rd and just East of its intersection with Albany Shaker Road, just up the hill from the Legion Hall.
They were built around 1950-1960, of rectangular drawn steel pans maybe 2x3 ft, bolted together through the flanges, sort of like giant Lego blocks stacked on edge. The steel pans were porcelanized with the color baked in. At least one of those houses has been disassembled and moved elsewhere, but most of them are still there. I think some have had other materials applied as sheathing, perhaps to conceal rust issues, perhaps for extra insulation.
A somewhat similar modular/cellular structure could work in FRP. Tooling could be relatively simple, even with interlocking features. Insulation could be less of a problem than with steel pans. Attaining a commercial production rate would require multiple tools because of the necessary curing time. FRP is likely to chalk in sunlight, so you'd need to start with gelcoat against the mold, or find a durable paint system.
There's another problem with FRP: VOC production, i.e., the stink and worse released during cure. Boatbuilders are now gravitating toward closed processes where the glass is laid up dry, and resin is introduced while the whole thing is in a vacuum bag. The process doesn't smell much, but it produces large quantities of expensive waste.
You could do something similar in concrete. In fact, it's already being done on a much larger scale, with tilt-ups, and on a smaller scale, with concrete blocks.
Mike Halloran
Pembroke Pines, FL, USA