If you are living in a space with a hipped roof—that is, one where the roof slopes down on all four sides—then a hip to gable loft conversion could be the perfect way to create valuable extra space.
This growingly famous loft conversion method converts one of those sloping roof sections into a vertical gable wall, which, as a result, increases the usable area and headroom inside your loft. But there are some common questions:
- What exactly does this mean?
- How does it differ from other loft conversion types?
- What should you anticipate in connection with the Cost? The Timeline? The Return on Investment?
In this complete guide, we will tell you everything you need to know about a hip-to-gable loft conversion, from design possibilities and permissions to real project costs and timelines.
Stick with us till the end – your dream space might just be a read away!
Let’s start the topic…
Understanding the Hip to Gable Loft Conversion
A hip roof slopes down on all sides—usually four—giving the house a distinctive pyramid-like shape on the roof. While attractive, these sloping hips restrict the usable space in the loft.
A hip-to-gable loft conversion involves removing the sloping hip on one or both sides and replacing it with a full-height gable wall.
This new vertical wall is capped with a standard pitched roof, significantly increasing the internal volume of your loft.
The benefits are clear:
Increased floor space
It is not like other loft conversion types that add only limited headroom or floor area. Hip to gable can add an extra whole room’s worth of floor space.
Better headroom
You can stand upright across most of the loft. It makes the space truly habitable.
Larger windows
The new gable wall provides a perfect surface to fit full-sized windows or skylights. It adds adequate space with natural light.
Maintains garden space
It is not like ground-floor extensions. It keeps your garden footprint remains untouced.
This type of loft conversions is basically suited to semi-detached and detached houses, mainly those with hipped roofs, but bungalows with similar roofs can benefit too.
Why Choose Hip to Gable Over Other Loft Conversion Types?
Before getting into the specifics, it is required to set the hip to gable conversion side by side with other common loft conversion styles to understand why it might be the best choice for your project.
Rooflight (Velux) Loft Conversions
These are the options that don’t come with a high price tag. It generally costs around £30,000 to £55,000. Rooflight conversion usually includes putting skylights in the existing roof without changing the structure. While they clear the way for light and give a sense of height, they don’t increase the usable floor area of headroom to a larger extent.
Dormer Loft Conversions
Dormers introduce space by extending part of the roof outward and building vertical walls with windows. They cost around £40,000 to £65,000 and provide more floor space than rooflights. However, they still leave some of the original sloping roof, limiting headroom.
Mansard Loft Conversions
Mansard conversions are the most pricier ones. The process includes altering the whole roof shape by increasing the rear wall and creating a flat floor with steep sides. They provide the most space but at a hefty price, often £55,000+ for about 30 square meters.
Hip to Gable: The Sweet Spot
Hip-to-gable loft conversions find a perfect balance between cost and space. They reconfigure the roof enough to add real volume and full-height space, generally costing £40,000 to £65,000 nationwide, with London and the South East commanding a 20% premium or more. Contrary to dormers and rooflights, you get more usable room for a similar or slightly higher budget.
Typical Costs for a Hip to Gable Loft Conversion in 2025
Understanding costs is important for planning. Hip to gable loft conversion prices depend on factors like location and quality of finish. Let’s understand general costs you can anticipate:
Core Budget Ranges
Standard Hip to Gable Conversion: £40,000–£65,000 (nationwide average)
London and South East Premium: £55,000–£90,000+ (due to higher labor and material costs)
Double Hip to Gable (both sides converted): £65,000–£80,000+, reaching £90,000+ in prime locations
Cost Per Square Meter
Standard quality: £1,250–£1,450/m²
Mid-range quality: £1,750–£2,000/m²
Premium build: £2,500–£3,500+/m²
A typical 35 m² mid-range loft conversion including :
- stairs
- insulation
- windows
- ensuite bathroom
It usually lands between £50,000 and £70,000 nationally, and £60,000 to £85,000 in high-demand regions.
Upfront Cost Breakdown
| Element | Typical Cost |
| Architect & Structural Plans | £1,000–£3,000 |
| Structural Engineer / RSJ | £500–£1,500 |
| Labour & Main Build | £10,000–£20,000 |
| Roof Restructuring & Gable Build | £10,000–£15,000 |
| Windows / Skylights (each) | £700–£1,500 |
| Staircase | £2,000–£5,000 |
| Electrics & Plumbing | £1,500–£3,000 each |
| Insulation | £2,000–£3,500 |
| Interior Finishes | £2,000–£4,000 |
| Ensuite/Bathroom | £5,000–£10,000+ |
| Contingency (10–15%) | £4,000–£10,000 |
Including VAT and extras, many standard builds range from £45,000 to £60,000, while high-spec versions can climb higher.
Real UK Hip to Gable Projects: What People Paid
Real-life examples from forums and trade blogs offer useful benchmarks:
- A house in London had a loft conversion with a side extension and a rear dormer & it was also having an ensuite bathroom. It cost around £50,000.
- If we talk about South West London or Surrey! A big loft with a double bedroom and a small bathroom costs more than £100,000. However, £60,000 is also possible for a simpler version.
- A mid-range loft conversion in Sheffield was priced at £62,000 before VAT.
- In South West England, a project added 35 m² of space, which included:
- Stairs
- An ensuite
- A rear dormer
- Big windows
This cost around £50,000.
These case studies highlight how location and project scope give rise to wide price variation.
The Build Timeline: From Plans to Your New Loft
Expect the entire hip to gable loft conversion process to take 6 to 12 weeks, depending on complexity:
| Week Range | Tasks |
| Weeks 1–2 | • Scaffolding erection • Removal of the hip roof • Installation of RSJ/steel supports • Building of the gable wall |
| Weeks 2–4 | • Re-roofing • Window installation • Weatherproofing • Initial insulation work |
| Weeks 4–6 | • Staircase installation • Electrical wiring • Plumbing • Internal board finishes |
| Weeks 6–8 | • Final plastering • Painting • Flooring • Fixing |
| Weeks 8–12 (if applicable) | • Ensuite tiling • Bathroom fixtures • Bespoke joinery |
Weather delays and design amendments can extend the timeline, but experienced contractors will manage schedules closely.
Permissions, Regulations, and Party Walls
Permitted Development
Hip to gable loft conversions often qualify under Permitted Development rights, provided they:
- Stay within volume limits (50 m³ for detached, 40 m³ for others).
- Use matching materials.
- Avoid balconies or other restricted features.
Party Wall Act
If your property shares a wall with a neighbour (semi-detached or terraced), you must notify them and potentially appoint a surveyor.
Building Regulations
Your project must comply with:
- Structural safety and stability.
- Fire safety, including smoke alarms.
- Insulation standards.
- Staircase headroom (minimum 2 meters).
- Sound insulation between floors.
Planning Permission
Required if:
- Your property is in a conservation area or is listed.
- The conversion exceeds permitted volume limits.
- You use non-matching materials.
Return on Investment: Value Boost and Cost Efficiency
A hip-to-gable loft conversion can add 20-30% to your home’s worth, according to RICS and Nationwide. If we set loft conversions with ground-floor extensions side by side, loft conversions provide excellent cost-per-square-meter value:
Loft conversions: £900–£2,500/m²
Extensions: £1,200–£2,250/m²
Loft conversions help preserve garden space, which is usually limited and valuable.
Tips to Keep Your Hip to Gable Loft Conversion Stress-Free and Cost-Effective
- Fix your specification early to stay away from costly mid-build changes.
- Use stud walls in place of blockwork to save time and money.
- Conduct DIY for non-structural finishes like painting and shelving to minimize labor costs.
- Restrict glazing to two or three windows to maintain a balance between light and costs.
- You should always have 10-15% contingency budget for surprises like asbestos or hidden roof damage.
Design Opportunities: Make the Most of Your New Loft Space
Luckily the extra headroom and floor area, a hip to gable loft conversion creates many creative possibilities:
Main Bedrooms: Big bedrooms with their own bathrooms and big walk-in closets.
Home Offices: Quiet and bright rooms upstairs which are away from noise and great for working.
Kids’ Rooms or Guest Rooms: Safe and comfortable spaces for children to play or for guests to stay.
Movie or Relaxing Rooms: Cozy spots to watch films or relax in peace.
Clever Space-Saving Ideas
Use Roof Space for Storage
Add storage in the lower parts of the roof to keep seasonal items like holiday decorations or winter clothes.
Let in More Natural Light
Install big Velux windows that open by themselves when needed and close when it rains.
Choose Open Staircases
Go for staircases that are open with built-in spaces to show off books or art, and help air move around the house.
Final Thoughts: Why a Hip to Gable Loft Conversion Is a Smart Investment
Converting your dirt-covered loft into a spacious and light-filler room with a hip to gable loft conversion is one of the successful ways to add habitable space without moving house or losing garden space.
- Gain 20–40 m² of usable floor area.
- Average costs range from £40k to £65k, with London and premium builds costing more.
- Build times are comparatively quick at 6–12 weeks.
- Expect up to 30% increase in property value.
- Create versatile spaces to improve your lifestyle and your home’s appearance.
If you are confused to make a decision between single or double hip conversions or need customized design, advice just ask. Your dream loft is within reach!Understanding the Hip to Gable Loft Conversion
