Almost certainly, because hardly anything here is old enough to start a fight over. There are no conservation areas. There are only a handful of listed buildings, and none in the top grades. The neighbours put in planning applications all the time. What's most likely to stop your extension is your budget.
Broadbridge Heath has 14 listed buildings. None is Grade I and none is Grade II*, so all 14 are Grade II, the standard tier for buildings of special interest. Listing matters a great deal if you own one of those 14: almost any change inside or out, down to windows, doors and fittings, needs listed building consent on top of any planning permission, and doing the work without it is a criminal offence rather than a paperwork slip. For everyone else, the listing map barely registers. There are also no conservation areas and no scheduled monuments within the area, which removes the two other layers that usually make a planning officer wince at a new porch.
What the neighbours are doing proves the point. Between April 2024 and June 2026 the area's planning records show 1,589 applications, 732 of them in the last twelve months. That's the paperwork trail of a place that's forever adding a room, a garage conversion, a loft or a rear extension. People here aren't asking whether they're allowed to build. They're asking the builder when he can start.
In practice, most homes here are ordinary houses in ordinary streets, and many modest extensions fall under permitted development: national rules that allow certain work, such as smaller rear extensions and some loft conversions, without a full planning application, within set limits on size and position. Outside a conservation area those rights aren't reduced by any area-wide designation, which is the norm here. Some newer estates can carry their own conditions that remove permitted development rights, and flats don't get them at all, so check the planning history and title of the specific house before assuming anything. Anything bigger, or anything on one of the listed buildings, goes to the council in the usual way. The usual way here tends to be a routine one.
Freedom to extend is one of Broadbridge Heath's real strengths: very little heritage, no conservation areas, and a planning file full of neighbours who have already done it. The planners are unlikely to stand in your way. The party wall surveyor might.