Yes, you can extend most houses in Wickham Bishops, and the heritage rules will rarely be what stops you. There is no conservation area. Only a few dozen buildings are listed. The neighbours apply for planning permission constantly. What needs thinking about is the clay under the house, and the paperwork matters much less.
Historic England lists 38 buildings in and around Wickham Bishops. None is grade I, 3 are grade II*, and the other 35 are grade II. Listing protects the whole building, inside and out, so nearly any change to one of the 38 needs listed building consent on top of anything else, and the council will expect the work to respect the original fabric. For everyone else, the list doesn't apply. Historic England's National Heritage List can be searched by address, and a five-minute search tells you which side of that line a particular house is on.
Wickham Bishops has no conservation area, which takes away the layer of control that elsewhere covers windows, doors, roofs and anything visible from the street. A homeowner here deals with the ordinary planning rules and nothing extra on top. For a village with this many large houses on large plots, it is surprisingly easy to do what you like with them.
The local planning records show people taking full advantage. In the area covering Wickham Bishops, 1,908 planning applications went in between April 2024 and June 2026, and 855 of them came in the last twelve months of that window. That count covers everything from loft conversions to whole new houses, and it says nothing about how many were approved. It does show that changing a house round here is routine, and that the people next door will very likely have had a builder in themselves.
The ground needs more thought than the paperwork. The British Geological Survey classes the risk of shrinking and swelling ground at class 3 at its worst point, and 100% of the area reaches that class. That means clay soil that swells when wet and shrinks in dry summers, so the ground under a footing moves with the seasons. For an extension, it means deeper foundations than a builder might quote by default, and it makes a structural engineer's view on the foundation design worth paying for. Trees near the new wall matter as well, because roots draw water out of clay. The heritage officer will have few opinions about your extension, but the clay will have plenty.
In practice, most houses in Wickham Bishops start from the national permitted development rules, which allow a range of rear, side and roof extensions without a full planning application, provided they stay within the size and height limits. Bigger schemes need planning permission in the usual way, and the 38 listed buildings need consent for almost everything. With about half the homes detached and plenty of bungalows on generous plots, there is usually room to build out, and the limits on height and size are set nationally rather than by any local heritage designation.
Freedom to extend is one of the village's real strengths. The council and Historic England will mostly leave you alone, and the ground is where the money has to go.