Yes on most homes. No on the listed ones. Slow on anything inside the conservation area. The parish carries 57 listed buildings, one Grade I and 56 Grade II. Around 406 planning applications were submitted across the parish in the last twelve months. The system works at its own pace.
The starting number is 57 listed buildings across the parish. One holds Grade I status. The other 56 sit at Grade II. Among the named listed structures are the Parish Church of the Holy Trinity, which has stood at the quay since the 800s and still carries original Saxon architecture in its tower along with a thirteenth-century crypt below the nave. The Old Town Hall has been here since 1694. The legal effect of listing is that any change touching a building's special interest needs listed-building consent on top of ordinary planning permission, and that can include internal works as well as external. Partition walls, services routing, internal joinery, window changes, roof coverings, chimney work: each can become a formal decision someone else signs off on. The reasonable assumption for any listed home in Bosham is that every meaningful change goes through a process before a builder starts.
On top of the listing regime, Bosham has its own conservation area, covering the historic core of the village. Conservation-area designation does not stop change the way listing does, but it strips out some of the permitted-development rights that householders elsewhere take for granted. Works that go through unchallenged on an ordinary street can need consent here: certain types of cladding, certain roof coverings, demolition of unlisted outbuildings, and some front-elevation alterations. Anyone buying a property within the historic core has to assume the planning team will read the proposal before the project starts, not after.
In practical terms, the question a buyer should answer before reading the brochure a second time is which of three categories the property falls into. Listed: extensive consent required, including for many interior works. Conservation area but unlisted: narrower permitted-development envelope, planning application likely for anything substantial, and a higher bar on materials and external character. Outside both: roughly the same envelope as anywhere else in the country, subject to the local plan. Around 406 planning applications were submitted across the wider parish area in the last twelve months, which is the rate of an actively used system rather than a sleeping one. Anyone planning a project should put the time and cost of consent into the buying budget, not into the after-exchange surprise category.
Freedom to extend or alter a home in Bosham scores average overall, because the answer depends entirely on which property a buyer is looking at. The non-listed, non-conservation-area homes around the parish edges sit in the ordinary national envelope. The listed and conservation-area properties at the historic core sit in a meaningfully tighter one. Read the constraints before reading the asking price.