Which puts the neighborhood under glass. If you are going to rebuild that means your payout needs to pay for the current value of the building, tear down fees, and new construction fees. If the neighborhood is in decline no problem - land is cheap and the buildings are not being maintained, but there is no demand to build anything there so nothing gets built. If the area is in demand land values are high, the people living there maintain their property (to ensure it keeps the value), and so the costs of building one more floor are always greater than the costs of keeping the building.