Hip to Gable Loft Conversion Cost London 2026: Complete Price Guide
- LCCL Construction
- 3 hours ago
- 3 min read
A hip to gable loft conversion transforms a hipped roof (sloping down on the side) into a vertical gable wall — creating substantially more headroom and usable floor space than a standard dormer conversion. Hip to gable is the highest-value loft conversion type for semi-detached, detached and end-of-terrace properties with hipped roofs. This guide gives you accurate 2026 hip to gable loft conversion costs so you can budget realistically before starting your project. LCCL Construction has delivered hundreds of hip to gable conversions across London and Hertfordshire.
How Much Does a Hip to Gable Loft Conversion Cost in London in 2026?
A hip to gable loft conversion in London costs between £50,000 and £95,000 in 2026 for a full design and build service. The average project cost is £62,000 to £78,000 depending on size, specification and location. This includes architectural design, planning permission where required, building regulations, structural calculations, party wall notices and all construction works from roof structure changes to finished plaster.
Hip to Gable Loft Conversion Cost by Size in London
Small hip to gable (18 sqm): £50,000 to £62,000.
Standard hip to gable (24 sqm): £62,000 to £78,000.
Large hip to gable with rear dormer (32 sqm): £78,000 to £95,000.
Combined hip to gable plus L-shaped dormer for maximum space can exceed £110,000.
Hip to Gable vs Standard Dormer: Cost Comparison
Standard dormer: £47,000 to £67,000.
Hip to gable: £50,000 to £95,000.
Hip to gable costs slightly more but delivers significantly more floor space — typically 20-30 per cent more usable area than a standard dormer on the same property. On hipped-roof properties hip to gable is almost always the better value option.
See our full hip to gable loft conversion guide.
What Is Included in a Hip to Gable Loft Conversion Cost?
LCCL Construction hip to gable costs include: measured building survey, architectural design, planning permission application, building regulations, structural engineer calculations, party wall notices where required, scaffold and welfare, roof structure works including the removal of the hip and construction of a new gable wall in matching brickwork, new roof structure over the extended space, insulation to current standards, new dormer window if required, staircase installation, first fix electrics and plumbing, ensuite bathroom installation labour, plastering, second fix and decoration. Bathroom sanitaryware and bedroom furniture typically client-supplied.
What Affects Hip to Gable Loft Conversion Cost?
The main factors are: size of the gable wall required, whether a rear dormer is added, complexity of matching existing brickwork, whether an ensuite bathroom is included, specification of windows including rooflights, planning permission complexity, party wall agreements for semi-detached properties (typically required) and location within London. Central London postcodes cost 15-25 per cent more than outer London.
Do Hip to Gable Loft Conversions Need Planning Permission?
Most hip to gable conversions fall within permitted development rights for semi-detached and detached houses in London (unless in conservation areas or under Article 4 directions). This is a significant advantage — no planning application needed, saving 8-12 weeks in the timeline. Building regulations approval is always required.
How Much Value Does a Hip to Gable Add?
A hip to gable conversion in London typically adds 150 to 275 per cent of the construction cost in property value. A £65,000 hip to gable typically adds £100,000 to £180,000 in outer London and £130,000 to £250,000+ in premium locations. See our full guide on how much value a loft conversion adds.
Frequently Asked Questions About Hip to Gable Cost
How much does a hip to gable loft conversion cost in London?
From £50,000 for a small hip to gable to £95,000 for a large hip to gable with rear dormer and premium specification.
How long does a hip to gable take?
Typically 10 to 14 weeks on site once construction starts. Add 6-10 weeks upfront for design and building regulations.
Can any semi-detached house have a hip to gable?
Most can — the property needs a hipped roof (sloping down on the side) and sufficient roof structure to work with. LCCL Construction assesses feasibility at the free initial consultation.
To get a free detailed estimate call LCCL Construction on 020 8037 7332 or get an instant quote online.
