Yes, in most of Clifton you can, because heritage rules cover very few of its houses. The village has no conservation area. Listed buildings number in the teens, and most of them are the lowest grade. The neighbours put in applications at a steady rate. The bigger obstacle in Clifton is the clay under the house.
Clifton has 15 listed buildings: none at Grade I, one at Grade II* and 14 at Grade II. Listing protects the inside of a building as well as the outside, so changing one needs listed building consent on top of any planning permission, and even small jobs can need it. For the rest of Clifton's homes, which make up nearly all of the village, that layer of control does not apply. Fifteen houses in a village this size have their history to consider, and everyone else only has the neighbours.
Central Bedfordshire Council's planning records hold 284 applications for Clifton between April 2024 and June 2026, and 122 of them came in the last twelve months. Those are applications only, with no outcomes attached. They show that altering a house is an ordinary thing to do here, and the planning notices on lamp posts are as much a part of village life as the bins going out.
The ground is the part to plan for. The British Geological Survey places Clifton in shrink-swell class 3, and every part of the village reaches that class. Shrink-swell clay swells when it is wet and shrinks when it dries out, so foundations for an extension usually go deeper than on firmer ground. That is more pronounced near trees, whose roots draw the moisture out. A structural engineer's view on foundation depth belongs in the budget from day one. In Clifton the clay has more say over a new kitchen than the council does.
For a house that is not listed and has no conservation area around it, many single-storey rear extensions, loft conversions and outbuildings can go ahead under permitted development, the national rights that allow certain work without a full planning application. Size limits still apply, and anything bigger or two-storey needs planning permission in the usual way. Some newer estates had those rights taken away by a condition on their original permission. Ask Central Bedfordshire Council whether permitted development rights still apply to the specific house, because a condition in a file from the estate's original permission can outrank anything you were told at the viewing.
Clifton gives owners a lot of freedom to change their homes. Very little of the village is protected, the paperwork is ordinary, and the real cost to plan for is going deeper into the clay.