In her letter to Broxtowe Borough Council, Housing Minister Esther McVey asked them to build on brownfield sites rather than the green belt. The letter was put in the public domain to signal to all local authorities that she expects them to develop brownfield sites first and only build on the green belt in exceptional circumstances. In her letter, she states:

I would like to take this opportunity to remind you of the importance this Government attaches to maximising the potential of previously developed land for new development, ensuring the efficient and appropriate use of land when planning to meet the housing need.

Whilst there are many ecological benefits to developing brownfield sites rather than greenfield land, there are also some ecological constraints.

A site left derelict for any length of time can develop into open mosaic habitats on previously developed land. These are habitats that are over 0.25ha in size with a history of disturbance and modification. These habitats can support early successional plant communities such as grasses, mosses and ruderal species which are attractive to range of invertebrates. Because of the biodiversity importance of open mosaic habitats, they are listed as a Habitat of Principal Importance under the NERC Act (2006) and are a material consideration in planning decisions.

Furthermore, abandoned buildings and structures on brownfield sites can become occupied by roosting bats and nesting birds, which are subject to legal protection.

Brownfield land can provide opportunities to increase the housing stock without impacting on the green belt, but not all brownfield land is the same and some areas support valuable flora and fauna in areas otherwise devoid of wildlife. It will be important to assess these sites to ensure that the most ecologically valuable ones are identified and protected.

New Stanton, Derbyshire