Two of the most popular loft conversion types in the South West are the dormer and the hip-to-gable. Both are excellent options — but they suit different homes and deliver different results. JM has completed dozens of each type across Somerset and Wiltshire, so we know exactly when each one is the right choice.
What is a Dormer Loft Conversion?
A dormer extends vertically from an existing roof slope, creating a box-shaped structure with full-height walls and a flat or slightly pitched roof. The key benefits are:
- Dramatically increases usable headroom and floor area
- Works on virtually any pitch roof (terraced, semi, or detached)
- Usually qualifies under Permitted Development
- The most popular conversion type across Somerset and Wiltshire
- Typical cost: £35,000–£50,000
What is a Hip-to-Gable Loft Conversion?
A hip-to-gable conversion replaces the sloping “hip” end of your roof with a vertical gable wall. This is only possible on homes with a hipped roof — typically semi-detached and detached properties built from the 1930s to 1980s. The key benefits are:
- Substantially increases internal loft area (often doubling usable space)
- Often combined with a rear dormer for maximum space gain
- Ideal for 1960s–80s semi-detached homes common in Trowbridge, Warminster, and Melksham
- Usually qualifies under Permitted Development for semi-detached homes
- Typical cost: £40,000–£55,000 (or up to £65,000 combined with a rear dormer)
Dormer vs Hip-to-Gable: Key Differences
| Feature | Dormer | Hip-to-Gable |
|---|---|---|
| Works on terraced homes? | Yes | No |
| Works on semi-detached? | Yes | Yes |
| Works on detached? | Yes | Yes |
| Typical cost | £35,000–£50,000 | £40,000–£55,000 |
| Space gain | Good | Very Good |
| Requires hipped roof? | No | Yes |
| Planning (typical) | Permitted Development | Permitted Development |
Which is Right for Your South West Home?
Choose a dormer if:
- You live in a Victorian or Edwardian terrace (Frome, Bath, Bradford on Avon)
- Your home already has reasonable head height in the loft
- Budget is a priority
Choose hip-to-gable if:
- You live in a 1960s–80s semi-detached or detached (Trowbridge, Warminster, Melksham)
- Your current loft has low or limited usable space
- You want to create two bedrooms or a large master suite
Not sure which is right for you? JM's free home survey will confirm your options. View all JM loft conversion services → or book your free survey →