No, once a house has been converted into flats or a maisonette, the Permitted Development rules that let most decking go ahead without an application no longer apply, for decking or for a pergola or pagoda at the same property. Any structure there needs a full planning application to whichever council covers the address, whatever its height or coverage.
Bournemouth's early growth spread villa housing through the lower Bourne valley from the 1840s onward, and a good number of those larger houses, especially around Boscombe Manor and the roads near Poole Park, have since been split into flats. A house on the same street that was never converted keeps its Permitted Development rights; the subdivided one next door does not, even for a low, flush deck. My decking planning permission page has the wider rules for houses that do qualify.
What changes if the house is listed or the garden lies in its curtilage?
Permitted Development stops applying to the deck. Planning Portal states plainly that “within the curtilage of a listed building, no decking or platform is permitted”, whatever the height, so a listed Bournemouth or Poole property needs a planning application for a deck that would need none next door. Listed building consent can be needed alongside that application where the work affects the building’s special interest, so check both with the council rather than one or the other.
Does a conservation-area address automatically mean the deck needs permission?
Not automatically, but the safe assumption changes. BCP Council designates 48 conservation areas, and inside one of them the kind of minor work you can do without an application is more limited than elsewhere, rather than banned outright. A modest, low deck may still be fine; the point is that the standard 30cm rule can no longer be assumed and needs checking against your specific address before you build.
Can a ground-floor flat or maisonette have a garden pagoda under permitted development?
No, for the same reason a flat cannot get decking under Permitted Development. Planning Portal is explicit that the rights covering common garden projects for houses do not extend to flats, maisonettes or other converted buildings, and that includes a freestanding pergola or pagoda. A ground-floor flat with its own garden still needs a planning application for one, regardless of size.
If you want a straight answer for your own garden, ring Alfie on 07841 319560.
Related: back to planning permission for decking and pergolas: the questions Bournemouth homeowners ask.
Related: do I need planning permission if any part of the deck is over 30 cm?