The ground
Upper Greensand · Gault clay
Central Didcot is mapped on Upper Greensand, a fine sandstone and siltstone, but Gault clay is mapped within half a kilometre to the north and east.
Where the Gault comes to the surface, expect heavy, slow-draining soil that bakes hard and cracks in summer. The British Geological Survey counts Gault among the clays most prone to shrink-swell, which matters for fence-post depth, patio sub-bases and planting close to buildings. Ground can vary from one garden to the next, so two gardens in the same street can behave differently.
Planning
Didcot Old · Station Road · Northbourne
Three conservation areas — Didcot Old, Station Road and Northbourne — lie within half a kilometre of the town centre. Inside one, you need to tell the council six weeks before tree work (unless the trunk is under 75 mm across, 1.5 m above the ground), and demolishing a boundary fence, wall or gate may need permission first.
Elsewhere, a boundary up to two metres tall, or one metre alongside a road, normally needs no planning permission. In a front garden, new paving covering more than five square metres has to be permeable — or drain to a lawn or border — to stay within permitted development.