Usually, yes. Most of Chalgrove is post-war housing that no heritage officer has strong feelings about. There is a listed core and one conservation area. The ground is clay that moves, so foundations need more thought than the planning does. The neighbours have been sending in plans steadily.
Chalgrove has 33 listed buildings. Two are Grade I, the top tier, none are Grade II*, and the other 31 are Grade II. Listing covers the whole building, inside and out, so changing a listed home means applying for listed building consent on top of any planning permission, and the council looks at materials, windows and layout. Altering a listed building without consent is a criminal offence. Thirty-three buildings is a small share of a village of family houses, but each of them comes with a long list of conditions.
The village has one conservation area, named after Chalgrove itself. Inside it, the council takes a closer interest in anything visible from the street, including extensions, demolition, cladding and changes to the front of the house. Work that would go through easily elsewhere in the village may need a full planning application there. Check the council's conservation area map, and the listed building register, for the exact address while the house is still a candidate. Whether it falls inside either decides which set of rules you are buying into.
Between April 2024 and June 2026, 528 planning applications were recorded for the area, and 256 of them came in the last twelve months. Those numbers show applications only, not how many were approved. They do show that a lot of people here are trying to change their homes.
The British Geological Survey rates the ground under every Chalgrove postcode at class 3 or higher on its shrink-swell scale, with class 3 the highest level found here. That means clay that swells when wet and shrinks when dry, and an extension built on it needs foundations designed for that movement. Expect to pay for deeper footings and a structural engineer's report, and pay attention to any large trees near where you plan to build. Here, the clay is a bigger factor in how much an extension costs than the planning rules are.
For most homes outside the conservation area and not listed, small rear extensions, loft conversions and outbuildings can often go ahead under permitted development, the national rules that allow some work without a planning application. Check whether those rights still apply to the house, because councils can remove them on individual homes or estates. Inside the conservation area those rights are narrower, and for a listed building almost any change needs consent. Most families looking for a bigger kitchen will be dealing with the clay rather than the council.
Freedom to extend in Chalgrove is about average. Most of the village leaves you fairly free to build, the heritage core restricts it, and the clay underneath adds cost everywhere.