Yes, usually, but more of Egham comes with paperwork than a buyer expects. The town and its surroundings carry well over a hundred listed buildings. Five conservation areas cover its older streets. Neighbours apply for planning permission constantly. Extending is normal here, and so is waiting for a decision.
The area around Egham holds 135 listed buildings: three at Grade I, eight at Grade II* and 124 at Grade II. Listing protects the whole building, inside and out, so on any of them most changes beyond basic repairs need listed building consent from the council on top of any planning permission. That covers more than extensions, since swapping windows, moving an internal wall or changing the roof can all need it. Grade II is the commonest grade and the least strict, though "least strict" still means asking before you touch almost anything.
There are five conservation areas, named for Egham, Egham Hythe, Englefield Green, Staines and Thorpe. Inside them, some of the work an ordinary house could do without permission needs an application instead, and the council looks harder at anything visible from the street, from extensions and dormers to cladding and the loss of a tree. The council can also add its own extra restrictions to particular streets, so the rules can differ from one road to the next. Ask Runnymede council to confirm in writing whether the house is listed, inside a conservation area or under any extra restrictions, and do it while you are still choosing between houses, since the seller's view of "probably fine" carries no legal weight.
The area has one scheduled monument, the strictest tier of protection, where almost any work needs national consent. A town first settled in the Bronze Age has left only one, and it matters mainly to anyone whose garden backs onto it.
The neighbours are not deterred. The council's register logged 2,759 planning applications in the Egham area between April 2024 and June 2026, 1,182 of them in the last twelve months. That counts applications made, not permissions granted, but it shows that altering a home here is ordinary business. Somebody on most roads has already been through the process and will describe it at length, given the chance.
In practice, a post-war semi or a newer house outside the conservation areas will often have permitted development rights, so a modest rear extension or loft conversion may need no planning application at all, subject to the national size limits and to the rights not having been removed for that property. Inside a conservation area those rights shrink, and on a listed building they mostly stop counting. The same rear extension can be a weekend's paperwork on one side of Egham and a long exchange of drawings on the other.
Freedom to extend in Egham is below average: plenty of homes can grow, but a buyer with plans needs to know which kind of house they are buying, and the older the street, the slower the yes.