Loft Conversion Costs in Bournemouth (2026 Guide)
Loft conversion costs in Bournemouth vary more than most people expect, and the biggest swing usually comes from the roof you already have rather than the room you want. A 1930s semi in Winton with a hipped roof is a very different job from a chalet bungalow in Kinson or a Victorian terrace near Boscombe, even if all three end up as a double bedroom with a shower room.
Below are the prices we'd realistically quote for 2026 across Bournemouth, Poole and Christchurch, what pushes a job up or down, and the planning and building regs points that catch people out.
How much does a loft conversion cost in Bournemouth?
These are all-in guide prices for a finished, signed-off loft room from our building and extensions team. They include structural steel, insulation, a new staircase, electrics, plastering and decoration, and they're based on current south coast rates for 2026.
Rooflight (Velux) conversion: £34,000 to £46,000. The cheapest route, but it only works if you've already got decent head height.
Bungalow loft conversion: £36,000 to £60,000, depending on whether it's rooflights only or a dormer as well.
Rear dormer: £50,000 to £72,000. This is the loft we build most often in Bournemouth.
Hip-to-gable with rear dormer: £66,000 to £84,000.
Mansard: from around £78,000, and often past £100,000 on larger houses.
Add an en-suite and you're looking at roughly £7,200 to £14,400 on top, depending on whether it's a simple shower room or a fully tiled walk-in shower. A bespoke staircase squeezed into a tight landing can add another £3,600 to £9,600.
What pushes the price up (or down)
We can't give anyone a firm number until we've been up in the loft with a tape measure. We always survey before quoting, and on loft jobs that visit decides most of the price.
Head height is the first thing we check. You want at least 2.2m from the top of the ceiling joists to the underside of the ridge for a comfortable room. Below that, you're into a dormer or hip-to-gable to create the space, or in rare cases lowering the ceilings underneath, which is messy and expensive.
Roof structure comes next. Plenty of post-war houses around Bournemouth were built with trussed rafters, the W-shaped timbers that fill the whole loft. They can be converted, but every truss has to come out and be replaced with a new structural frame and steels, and that's more labour than an older cut-timber roof.
Then there's access. Terraces in Boscombe and Springbourne often mean scaffolding over a shared path and every bag of plaster carried through the house. Detached homes in Queen's Park or Talbot Woods usually have room for a skip and a materials drop on the drive, which saves days.
Finally, the finish. Underfloor heating, fitted joinery in the eaves and a properly built en-suite all add cost, but they're also what makes a loft feel like part of the house rather than a box on top of it.
Do you need planning permission for a loft conversion in Bournemouth?
Often not. Most loft conversions fall under permitted development, provided the extra roof space stays within 40 cubic metres for a terraced house or 50 cubic metres for a semi or detached home, nothing goes higher than the existing ridge, and dormers sit on the back or side rather than facing the road.
There are exceptions. Flats and maisonettes don't have permitted development rights. Nor do houses in conservation areas for this kind of roof work, and BCP Council has several in Bournemouth, including Meyrick Park and Talbot Woods, and the East Cliff. Some streets also have Article 4 directions that remove those rights. If you're in any of those, you'll need a full householder application.
Even when planning isn't needed, we'd recommend getting a lawful development certificate from the council. It's cheap insurance for when you sell, and buyers' solicitors increasingly ask for one.
Building regulations approval is needed on every loft conversion, no exceptions. That covers structure, insulation, stair headroom, sound insulation between floors and fire safety. On a typical two-storey house the loft makes it three storeys, so you'll usually need a protected stairway with fire doors down to the front door and mains-wired, interlinked smoke alarms. Semis and terraces also need party wall notices served on the neighbours before work starts. We handle all of this and hand over the paperwork you should expect from your builder at the end.
How long does a loft conversion take?
On site, most rear dormers we build take around 8 to 12 weeks from scaffold going up to final decoration. Simple rooflight conversions are quicker; mansards and hip-to-gables sit at the longer end.
Before that, allow time for drawings, structural calculations and building control, and add roughly eight weeks if you need planning permission. If you're thinking about a spring start, getting the survey done this autumn is the sensible move. It also means the roof gets opened up in drier weather rather than the middle of a south coast winter.
One thing people are pleasantly surprised by: most of the work happens from the scaffold, so you can usually stay living at home throughout. The disruptive bit is the week or so when we break through for the new staircase.
Related reading
Get a loft conversion quote in Bournemouth
If you're in Bournemouth, Poole, Christchurch or nearby and want to know what your loft could become, we'll come out, get into the roof space and give you a fixed, itemised price with drawings and building control sorted for you. Book your loft survey with Complete Builds and we'll take it from there.
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