Usually yes, provided the house is one of Wendover's post-war semis and not one of its old buildings. The town has about a hundred listed buildings. The historic centre is a conservation area. Most of the newer homes are outside it and face the ordinary rules. Your freedom depends on which part of Wendover you buy in.
Historic England lists 100 buildings in the Wendover area: none at Grade I, four at Grade II* and 96 at Grade II. Listing covers the inside of a building as well as the outside, so replacing windows, removing a wall or changing a staircase in one of them needs listed building consent, and the usual permitted development rights mostly do not apply. Many of the buildings on the High Street, Pound Street and Aylesbury Road date from the 17th century. Whoever owns one now is looking after it more than altering it.
Wendover has one conservation area, covering the old centre. Inside it, Buckinghamshire Council expects alterations to keep the character of the street, so side extensions, roof changes, cladding and work visible from the road all get closer scrutiny than they would on an estate a few streets away. The old town still keeps its medieval layout of long, narrow plots, which leaves little room to build sideways and a lot of neighbours on both sides.
There are three scheduled monuments in and around the area, among them the Iron Age hillfort of Boddington Camp. Scheduling is the strictest form of heritage protection, but it mainly affects land on or next to a monument, and very few homes are that close.
People do extend their homes here, and often. Buckinghamshire Council received 526 planning applications for the area between April 2024 and June 2026, 488 of them in the last twelve months of that period. That is plenty of extensions, loft conversions and new windows going through the system, and plenty of neighbours who will have read each one.
For a typical post-war semi outside the conservation area, the standard permitted development rights for rear extensions and loft conversions should apply, unless something in the property's own planning history has removed them. Anything listed, or anything in the old centre that changes what can be seen from the street, will need consent. A planning search with the council will show whether a house is listed, inside the conservation area, or has had its permitted development rights removed. That costs a few days, compared with discovering the problem once the scaffolding is up.
Wendover's rules on extending are middling: most semis away from the centre can be extended without much fuss, while a house on the old High Street comes with three centuries of character the council intends to protect.