This has a lot more to do with zoning and urban planning that it does with the mortgage as a financial product. On the majority of lots in most cities it's ver

This has a lot more to do with zoning and urban planning that it does with the mortgage as a financial product. On the majority of lots in most cities it's very difficult (or illegal) to build new housing. That's a regulatory constraint that has nothing to do with how the house is financed.