Mostly yes. Most of the houses are too young for anyone to have listed them. Listed buildings are rare. Two conservation areas sit around the edges of the village. The neighbours put in planning applications all the time. The bigger obstacle is usually the clay under the foundations, not the heritage rules.
There are 19 listed buildings in and around Sonning Common. None is Grade I, one is Grade II* and 18 are Grade II. If you own one of them, you need listed building consent for almost any change, inside or out, and replacing a window becomes a conversation with the council. For everyone else, 19 is a small number for a village of this size. The odds of your house being on the list are low, so check the listing register for the exact address and move on.
Two conservation areas, Greys Green and Rotherfield Peppard, fall within the wider area. Inside a conservation area, changes to the look of a house from the street get more scrutiny, and some work that would be routine elsewhere needs a formal application. The brief carries no record of extra local restrictions on top of that, so check with South Oxfordshire before assuming either way. About 23% of the wider area also sits in the Chilterns Area of Outstanding Natural Beauty. Designated landscapes of that kind can narrow what you're allowed to build without asking. The post-war estate streets are what most buyers are looking at, and they sit outside both conservation areas.
The planning records show how often people alter their homes here. Between September 2023 and June 2026 there were 3,194 applications in the planning data for the area, with 1,424 of them in the most recent twelve months. That tells you people extend, convert and rebuild here, and that nobody who put in an application was unusual for doing so. It says nothing about how many were approved, so don't read it as a promise.
The ground deserves more thought than the heritage. The British Geological Survey rates the area's shrink-swell hazard at class 3 at worst, and about 94% of the area reaches that class. Shrink-swell clay expands when wet and contracts when dry, and large trees nearby make it worse. For an extension, expect deeper foundations than a builder quoting from memory might assume. Get a structural engineer to look at the soil and the trees before the architect draws anything. Surprise foundations are a common way for an extension to go over budget.
In practice, a single-storey rear extension or a loft conversion on an ordinary house outside the conservation areas and the protected landscape may well fall under permitted development. That means no planning application is needed, as long as it stays within the national size limits. Anything bigger, anything facing the street in a conservation area, or anything touching a listed building needs consent. Ask the council for a lawful development certificate before you start. It costs far less than an enforcement notice.
Extending here is middling rather than easy. The heritage rules leave most houses alone, but the protected landscape, the two conservation areas and the clay all need checking, so plan for them.