The ground
Head · chalk
Head over chalk is what the map shows at Turville’s centre. Head, in the British Geological Survey’s words, is a poorly sorted deposit of gravel, sand and clay, formed mostly as soil and rock debris crept slowly downslope.
Half a kilometre out, the chalk has no cover at every point but one: to the south-east, the Head carries on. Expect alkaline, chalky ground, which the RHS says can be either light or heavy; where clay is present, it holds more water.
Planning
Chilterns National Landscape · Turville Conservation Area
Turville is about 5.2 km inside the Chilterns National Landscape, with its centre inside the Turville Conservation Area; Fingest’s conservation area lies about 0.8 km off. National Landscapes and conservation areas both count as designated land. A garden building put up beside the house therefore needs planning permission, and the ground covered by buildings, enclosures and pools more than 20 metres from the house can add up to no more than 10 square metres.
In the conservation area, Buckinghamshire Council needs six weeks’ notice before tree work, except on trees less than 75 mm in diameter, measured over the bark 1.5 m up; where a Tree Preservation Order applies, its rules take precedence. Taking down a fence, wall or gate there may need permission too.