Yes, in most of Deanshanger you can extend a house without much trouble. The village has very little heritage protection for its size. Its listed buildings are few, and all of them are in the lowest grade. There is one conservation area. In most of the village the planning officer has nothing historic to protect, so the questions are about your neighbours' light and your own foundations.
The national heritage list includes seven buildings in Deanshanger, all of them Grade II. None are Grade I or Grade II*. Listing covers the whole building, inside and out, so almost any change to one of those seven needs listed building consent on top of ordinary planning permission. For every other house in the village, listing is someone else's problem. Legend puts a monastery here in Becket's time, and it left no buildings for the planners to protect.
West Northamptonshire Council has designated one conservation area, called Deanshanger. Inside it, the council can control things that would be routine elsewhere, such as the street-facing side of a house, demolition, and work to trees. Plans that would go through easily two streets away get more scrutiny inside the boundary. Look up the exact address on the council's conservation area map early, because conservation area status is easily left off a property listing.
The planning register shows how much building goes on. Across the area, 482 planning applications were submitted between April 2024 and July 2026, and 204 of them in the last twelve months of that period. Those numbers cover everything from loft conversions to new homes, and they show that people here change their houses as a matter of routine. The planning register is the busiest noticeboard in the village.
The ground is the more technical issue. The British Geological Survey rates the area's shrink-swell hazard at up to class 3, and about 24% of the area reaches that class or higher. Shrink-swell is clay that swells when it is wet and shrinks when it dries, and it moves foundations with it. Extensions on that kind of ground usually need deeper foundations, sometimes more so near trees. Get a structural engineer's opinion before the architect finishes the drawings. The planning risk is small, and this is a practical cost to plan for.
The village is mostly post-war and modern housing outside the conservation area, so a typical house will often be able to add a modest rear extension or convert the loft under permitted development, using rights that come with the house without a full planning application. Inside the conservation area those rights are narrower, and for the seven listed buildings they hardly apply. Confirm in writing with the council that your project counts as permitted development, because a builder's confidence is no substitute.
The freedom to extend is one of Deanshanger's real strengths. For most houses, the bigger limits are the clay underneath and the budget for foundations.