Mostly yes, unless the house is up the hill. Two dozen listed buildings, nearly all of them Grade II. Thirteen conservation areas, several around Coombe. Hundreds of neighbours apply for planning permission every year. The clay underneath gets a say too, and it has nothing to do with planning.
New Malden has 24 listed buildings. None is Grade I, one is Grade II* and 23 are Grade II. Listing covers the whole building, inside and out, so almost any alteration needs listed building consent from the council as well as planning permission. Doing the work without consent is a criminal offence. If yours is one of the 24, the planning officer becomes a co-owner who never pays towards the boiler.
Thirteen conservation areas fall in or around New Malden, among them Coombe Hill, Copse Hill, Drax Avenue, Durham Road and Lambton Road. Inside one, the council takes a closer interest in what faces the street: rooflines, front extensions, cladding and trees can all need consent that would be automatic elsewhere. The larger 1930s detached houses went up on the way to Coombe Hill, so the bigger the house, the more likely it is to be inside a boundary. Kingston upon Thames council publishes its conservation area maps, and it is worth checking the exact boundary for any house on your list, since a road can be split between one side and the other.
There are 3 scheduled monuments in or around the area. Scheduling is the strictest protection there is, but it only matters for land next to or containing one.
The neighbours are not deterred. Between March 2024 and June 2026, 1,326 planning applications were made in New Malden, 518 of them in the last twelve months. That is a suburb that would sooner build out the back than pay stamp duty twice.
The ground needs as much attention as the paperwork. Every New Malden postcode is in class 3 on the geological survey's shrink-swell scale, the rating for clay that expands when wet and shrinks when dry. That does not stop an extension, but it does mean deeper foundations, more care around trees and a structural engineer involved from the start. The clay sets the depth of the foundations, and the depth sets the bill.
One listed building in the area is on Historic England's Heritage at Risk register. Its repairs may qualify for grant help, and any work on it will be closely watched. For the owner of an ordinary house down the road it changes nothing.
For an unlisted house outside a conservation area, the national permitted development rules often cover a modest rear extension or a loft conversion without a full planning application. A lawful development certificate from the council confirms the work is allowed in writing. "Potential to extend, subject to planning" is a phrase the particulars use as if the "subject to planning" part were a formality. In a conservation area or on a listed building it is the hard part.
Freedom to alter a home in New Malden is below average. Ordinary semis on the flat are usually straightforward, but the conservation areas, the listed buildings and the clay make a lot of projects slow, costly or both.