Loft Conversion Cost: Complete Breakdown 2026 in Bournemouth
A loft conversion is one of the best-value home improvements — it adds a bedroom and bathroom without losing garden space. Costs range from £30,000 for a simple Velux conversion to £90,000 for a full mansard, depending on the type and specification. Here is what Bournemouth homeowners should expect to pay.
Local cost range — Bournemouth
£38,000–£70,000
What affects costs in Bournemouth
Bournemouth's Victorian and Edwardian terraces suit rear dormer conversions. Front-facing dormers in conservation areas need planning permission and sympathetic design.
Cost estimator
Rates for Bournemouth
6m × 4m = 24m²
Estimated cost in Bournemouth
Excl. VAT (£10373 – £15272)
Local insight: Bournemouth's Victorian terraces often need party wall agreements on both sides, adding £1,400–£3,000 to the total. Side-return extensions on terraces are the most common project here.
Cost breakdown
Cost by conversion type
Velux/rooflight: £30,000–£45,000 (simplest, no structural roof changes). Rear dormer: £40,000–£60,000 (most popular, adds headroom). L-shaped dormer: £50,000–£70,000 (two dormers meeting at a corner). Hip-to-gable + dormer: £55,000–£75,000 (maximises space on hipped roofs). Mansard: £65,000–£90,000 (most complex, most space).
What drives the cost
The main cost factors are: (1) type of conversion (dormer/mansard cost more than Velux); (2) size (one room or two); (3) en-suite bathroom (adds £5,000–£10,000); (4) staircase complexity (over the existing stair is cheapest); (5) access difficulty (scaffolding costs vary).
Professional fees for loft conversions
Design starts with the Layout Ideas Pack, done remotely or in person (subject to coverage). Structural calculations (always needed for floor joists and any roof steels), the planning application, and Building Regulations drawings are priced after that. The council also charges a planning application fee if one is required, set nationally and revised each year — the Planning Portal lists the current fees. Building control fees are separate.
| Type | Build Cost | Estimated Total |
|---|---|---|
| Velux/rooflight | £30,000–£45,000 | £35,000–£55,000 |
| Rear dormer | £40,000–£60,000 | £48,000–£72,000 |
| L-shaped dormer | £50,000–£70,000 | £58,000–£82,000 |
| Hip-to-gable + dormer | £55,000–£75,000 | £63,000–£88,000 |
| Mansard | £65,000–£90,000 | £75,000–£105,000 |
National guide figures. Local rates in Bournemouth: £38,000–£70,000.
Frequently asked questions
National guide
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