The Thames Basin Heaths SPA is made up of 13 Sites of Special Scientific Interest, and consists of a mixture of heathland, mire, and woodland habitats. They are essentially ‘heathy’ in character. The topography is varied and most sites have a large component of trees and some contain streams, ponds and small lakes. Some are freely accessible to the public and most have a degree of pubic access, though in some areas this is restricted by army, forestry or other operations. 

The Thames Basin Heaths Special Protection Area (TBH SPA) was designated on 9th March 2005 and forms part of Natura 2000, a European-wide network of sites of international importance for nature conservation established under the European Community Wild Birds and Habitat directives. The TBH SPA is one of the South East's most important natural assets with the lowland heath supporting important populations of Dartford Warbler, Nightjar and Woodlark - vulnerable ground-nesting birds.

The European and national legislation that underpins the SPA seeks to ensure that any proposed development scheme or plan will not adversely affect the integrity of the SPA. Natural England is the Government agency that champions the conservation of wildlife throughout England. They have advised all Local Authorities with land in the Thames Basin Heaths that new housing within 5km of the SPA may harm the rare bird populations and that particular harm may occur from additional new development that lies within 400m of the SPA. This harm can be caused by disturbance to the birds from a growth in the number of walkers, cats and dogs frequenting the heathland, and other recreational uses created by additional housing.