Conservation Design Subdivision ordinances allow communities to preserve the overall density of development while protecting open spaces and important natural and cultural resources. Typically, the lot sizes for the zoning district the land is in determines the overall density, but but actual lots are some fraction, 1/2, for example, of that base zoning lot size. Requirements are often placed on what part of the property is preserved as well, with priority given to important local natural or cultural features.
Allows density to shifted to areas best able to accommodate it, while protecting sensitive lands. The owners of land in the restricted sensitive areas can receive partial compensation to offset the loss of their development potential, potentially sidestepping a legal "takings" challenge to the land restrictions.
It is easy to identify "transfer out" zones of sensitive or hazardous areas, but harder to identify "transfer in" zones for the shifted density, since nobody usually wants to live next door to a denser development. There are also government costs and administrative burdens in tracking and monitoring the development rights sales and transfers, to ensure proper densities are achieved in the transfer-in and transfer-out zones.
Example 1: Ohio
Description: Ohio Balanced Growth Program (does not necessarily fit here; however, describes incentives for participating in Balanced Growth Program).