This article reviews some trends in the sociotechnical development of urban spaces and controlled environments. It provides past and present examples of spatial, volumetric and symbolic constructions that have functioned to enclose or divide before describing a new context of markets that promise to provide habitats or settlements offering ‘environmental exemption’. In other words, this is the ability to pay for access to ‘clean’, ‘green’, ‘pure’ and ‘politically free’ environments. Examples of existing and proposed eco-enclaves of various kinds are given and discussed. The conclusion considers some implications of these possible projects of ‘salvation’ or ‘segregation’.