Yes. In Clapham, Bedfordshire you can extend almost any house through the ordinary planning system, with no extra heritage rules on top. Four buildings are listed. There is no conservation area. Neighbours lodge hundreds of planning applications. The thing most likely to push back on your plans is the clay under the house.
Historic England lists four buildings in the Clapham area. One is Grade I, the highest grade, none is Grade II*, and three are Grade II. Owners of a listed building need listed building consent for almost any change to it, inside or out, alongside any planning permission. Four is the entire list for the village. For everyone else, listed building consent never comes into it, and most houses here were built long after anyone was listing anything.
The planning records show 785 applications across the area between April 2024 and June 2026, with 370 in the last twelve months. That shows how often people here alter their homes. Whatever you have in mind, the council has dealt with plenty of applications like it. A useful check is to look up the street on Bedford Borough Council's planning portal and read what the neighbours applied for, along with the drawings they submitted.
The ground needs more attention than the paperwork. The British Geological Survey puts every postcode in Clapham in class 3 on its shrink-swell scale. That is a published hazard class for clay soils that swell when wet and shrink when dry, and it covers the whole area. For an extension, it usually means deeper foundations than you might expect, more care near trees, and a structural engineer's view on the design. Building control will ask about it in any case. A side extension on clay can need more spent below ground than above it, so get the foundations priced before you commit to the rest of the design.
In practice, many single-storey rear extensions, loft conversions and smaller changes can fall under permitted development, the national rules that allow certain work without a full planning application, as long as the house is not one of the four listed buildings and is not a flat. Anything bigger goes through an ordinary householder planning application, judged under the standard rules with no conservation area involved. Building regulations apply either way, and the clay is a building regulations question.
This is one of Clapham's real strengths. Planning is straightforward, and the main thing that needs careful handling is the clay under the foundations.