Originally Posted by 
Zojha
				
			 
			Sounds plausible - until you realize that the interior of the houses has to be allocated as an instance either way, so you're not saving those 2124 instances, you only have 36 more. Moreover, every FC house can have up to 512 more instances inside it - Private chambers. If the amount of instances was an issue, people using that potential would be a veritable nightmare for them.
If they had wanted to save instances, they'd have had to design the exterior of the house to fit with the interior, so that both are in the same instance. Easy to do when one house is one instance, a lot less so when 30 houses make one instance (Subdivisions are a new Instance IIRC).