Yes, and a lot of Worcester Park already has. There are eight listed buildings in total. The only conservation area is Old Malden. Nearly 300 planning applications go in each year. The council rarely gets in the way. The clay underneath is the bigger obstacle.
Historic England's register lists 8 buildings in Worcester Park, all Grade II, with none at Grade I or Grade II*. Listing protects the whole building, inside and out, so even modest changes to a listed home need listed building consent on top of any planning permission. Altering one without consent is a criminal offence. Eight buildings in an area of more than 12,000 households means the odds of buying one by accident are small. If you do, you'll know, because it'll be in the conveyancing search.
There's one conservation area, Old Malden, on the Kingston side of the post town. Inside it, the council takes a closer interest in anything visible from the street, and work that would be routine elsewhere can need a full application. Outside it, the interwar streets have no special designation at all. For land that was once part of the Great Park of Nonsuch, Worcester Park is remarkably relaxed about what you put on the back of a semi.
The neighbours certainly aren't holding back. The planning register logged 751 applications in Worcester Park between April 2024 and June 2026, with 292 in the most recent twelve months. Those are applications, not decisions, so they tell you how much people want to build here and nothing about how many got permission. Every few streets, a scaffold tower suggests a loft conversion in progress.
The ground is the real constraint. The British Geological Survey rates the area at class 3 for shrink-swell clay, and every postcode reaches that class. Clay soil swells when wet and shrinks when dry, so it moves with the seasons and with the roots of nearby trees, and extensions are where that movement tends to show. It means deeper foundations than you'd use on firmer ground, and possibly a structural engineer's design if there are large trees close by. Budget for the foundations before choosing the kitchen units. A new extension with shallow foundations can crack away from the original house.
Permitted development is the national set of rights that lets some extensions and loft conversions go ahead without a full planning application, within set size limits. It applies to most of Worcester Park's unlisted houses outside Old Malden. Flats don't get the same rights, and listed buildings and conservation areas get fewer. Worcester Park also covers parts of three councils (Sutton, Epsom and Ewell, and Kingston upon Thames), so check which one your address falls under, then ask that council for a lawful development certificate so you have written confirmation that the project is allowed before building starts.
Extending a home is one of the easier things to do in Worcester Park. The planning rules are light, so the cost of getting through planning is small, and most of the extra expense goes into the foundations.