Mostly yes, and plenty of the neighbours already have. Only a handful of homes are listed. There's no conservation area in the village. Planning applications arrive at a steady rate. The protected landscape is what slows you down more than any old building.
Historic England lists 15 buildings in Icklesham: 1 at Grade I, none at Grade II* and 14 at Grade II. Listing covers the whole building, inside and out, so even a new window, an internal wall or a change of roof tiles on a listed home needs listed building consent on top of any planning permission. Grade I is the top tier and is treated as close to untouchable. Buy one of these 15 and you're its custodian, doing the work under someone else's supervision. For everyone else, the list isn't your problem.
There is 1 scheduled monument nearby, the strictest level of heritage protection. It matters mainly if your land runs up against it, and any groundwork near it needs separate consent.
The neighbours' planning history shows people do alter homes here. From April 2024 to June 2026, 96 planning applications were submitted in the area, 33 of them in the last twelve months. That doesn't tell you how many were approved. It does tell you that extending a house is a normal thing to do in Icklesham, and that someone on your lane has probably already been through the process and has opinions about it.
In practice, most homes here aren't listed and there's no conservation area in the village, so many smaller jobs may fall under permitted development, the rights that let you do some work without a full application. The complication is that all of Icklesham sits inside the High Weald Area of Outstanding Natural Beauty, and homes in protected landscapes can have fewer of those automatic rights than homes elsewhere. With about 30% of the housing made up of bungalows, the obvious ambition is to build up into the roof. Ask Rother District Council for a written confirmation, called a lawful development certificate, before you buy on the strength of a loft conversion rather than after the builders have booked the scaffolding.
Your freedom to extend is one of Icklesham's stronger points: few listed buildings, no conservation area and a steady run of neighbours' applications. The protected landscape asks for care with what the extension looks like, but it doesn't rule out extending.