Greyfield land
Greyfield land is underused real estate assets or land. The word greyfield is a relative neologism as compared to more commonly known terms such as brownfield and greenfield.
The term applies specifically to underused buildings and land in towns and cities that could be intensified by the addition of rooftop developments (in the case of an existing building) or airspace developments (above an existing carpark, for example), whilst largely maintaining the original existing use.
Continued use and intensification differentiates greyfield from: "brownfield" which invariably involves demolition / wholesale re-purposing of the land; or "grey-belt" a recently coined portmanteau describing poor quality "green-belt".
