FWIW that's how all the trusses on your house were probably done. I think it's mostly a cost/benefit tradeoff. My hunch is that the overhead of building on-sit

FWIW that's how all the trusses on your house were probably done. I think it's mostly a cost/benefit tradeoff. My hunch is that the overhead of building on-site isn't that great when you have to figure in the overhead of shipping/designing something in a modular way. Pretty much everything is 8ft long in terms of building materials which makes it much easier to transport.