Of course, you have to consider the incentives for builders when it comes to house sizes. A lot of cities have lot size requirements or setback requirements tha

Of course, you have to consider the incentives for builders when it comes to house sizes. A lot of cities have lot size requirements or setback requirements that make it pointless to build smaller houses because the lot has to be a certain minimum size anyway. This is also why rowhouses are so expensive: people like them, but in most US cities nobody is allowed to build new ones.