Usually, unless your house has a listing certificate hanging over it. Most homes carry no heritage protection at all. Fewer than two hundred buildings are listed. The neighbours file planning applications at a steady clip. Here, the thing most likely to slow your extension is the neighbour who files an objection.
Broadstairs has 176 listed buildings. One is Grade I, the top tier reserved for buildings of exceptional national interest. Four are Grade II star, and the other 171 are Grade II. Listing covers the whole building, inside and out, and any change that affects its character needs listed building consent on top of ordinary planning permission, whether that's a rear extension, new windows or ripping out a fireplace someone in 1850 was proud of. Doing the work without consent is a criminal offence, not a paperwork slip, and it follows the house to the next buyer. If the property you're viewing is one of the 176, budget for a heritage specialist before you budget for the kitchen.
There are also two scheduled monuments in the area, the strictest tier of protection going. They matter mainly if your land sits next to or on top of one, in which case digging a new foundation becomes a conversation with national heritage bodies, not a builder.
The neighbours are clearly getting on with it. Across the town, 2,002 planning applications were lodged between April 2024 and June 2026, with 821 in the most recent twelve months. That is live evidence that people alter homes here all the time. Every loft, porch and side return on those forms belongs to someone who decided moving was more trouble than building.
For an ordinary unlisted house, which is most of Broadstairs, many smaller changes such as modest rear extensions and some loft conversions can fall under permitted development, the national rules that allow certain work without a full planning application. Size limits and conditions apply, flats don't get the same rights, and a council can remove them in particular places, so check with Thanet's planning team before assuming anything. Anything larger, anything forward of the front wall, or anything on a listed building goes through the full application route. A lawful development certificate costs less than a demolition order and settles the question in writing.
Your freedom to extend in Broadstairs is middling: a normal house faces the normal rules, and the listed minority faces a much longer conversation.