Yes, you can extend most houses in Long Hanborough, and plenty of residents are already doing it. There are few listed buildings, and none are in the higher grades. There is one conservation area. The clay underneath causes more trouble than the conservation officer. Most of the work ends up underground, in deeper foundations.
There are 23 listed buildings in the area, all Grade II. None is Grade I and none is Grade II*. Grade II is the commonest form of listing, but it still covers the whole building, inside and out. Replacing windows, removing an internal wall or adding a rear extension to a listed house all need listed building consent as well as planning permission, and doing the work without consent is a criminal offence, not just a planning matter. Twenty-three houses in a village this size makes listing a problem for a few owners. For everyone else it is somebody else's paperwork.
There is one conservation area, Millwood End. Inside it, the council takes more interest in anything visible from the street. Demolition, front-facing alterations and some works that would not need permission elsewhere need consent there, and trees are protected too. Look up the address on West Oxfordshire's conservation area map early, because whether a house is just inside or just outside the boundary decides how much of this applies.
The council recorded 1,082 planning applications for the area between April 2024 and June 2026, 538 of them in the most recent twelve months. Those are applications, not approvals, and the numbers do not show how many were granted. They do show that a lot of people here are applying. A good share of the village is planning a kitchen extension at any given time, and the neighbours have usually done one themselves.
The ground needs more thought than the planning rules. The British Geological Survey places the area in class 3 for shrink-swell clay, and that covers the whole area. Shrink-swell clay expands when wet and contracts when dry, which moves shallow foundations, especially near trees. For an extension, it usually means deeper foundations and a structural engineer's report early in the design. Expect the extra cost to show up in the groundworks quote. It is a normal part of building on this soil and no reason to give up on the project.
For most of Long Hanborough, an ordinary rear or side extension to an unlisted house outside Millwood End will go through permitted development or a standard householder application. Owners of listed houses and homes inside the conservation area should budget for consent from the start and plan on a longer timetable.
Freedom to extend in Long Hanborough is about average. The planning rules are light for most of the village, but the clay makes almost every extension cost more underground.