nostr:npub105955g40jks026wlyecptdcsqaf5t0ep5pl6cgqu95qxpeapm2rqj89pe2 

Well, formally they are different: system building is the method of off-site prefabrication of standard components then assembled on-site.... #RAAC was one of the key components used to further reduce costs of transport (due to weight) & materials.... you can have systems building without RAAC & RAAC can be used (and has been) in other building methods.