A loft conversion is one of the most popular home improvement projects in the UK, adding valuable living space and increasing property value by 15 to 20 percent on average. But with several types available, choosing the right conversion for your home can be confusing.
1. Velux (Rooflight) Conversion
The simplest and most affordable type of loft conversion, a Velux conversion involves adding roof windows to the existing roof structure without altering the external shape. This option works best for lofts that already have sufficient headroom of at least 2.2 metres at the highest point.
Best for: Properties with high ridge lines and adequate existing headroom. Ideal for bedrooms, home offices, or playrooms.
Planning permission: Usually falls under Permitted Development rights.
Typical timeline: 4 to 6 weeks.
2. Dormer Conversion
A dormer conversion extends outward from the existing roof slope, creating additional floor space and full-height headroom. Rear dormers are the most common and can span the full width of the property. This is the most popular loft conversion type in the UK.
Best for: Semi-detached and terraced houses that need more headroom than the existing roof allows.
Planning permission: Rear dormers typically fall under Permitted Development. Front-facing dormers usually require planning permission.
Typical timeline: 8 to 10 weeks.
3. Hip-to-Gable Conversion
This conversion type extends the sloping side of a hipped roof outward to create a vertical gable wall, significantly increasing the usable loft space. It is commonly combined with a rear dormer for maximum floor area.
Best for: Semi-detached houses with hipped roofs that need significant additional space.
Planning permission: May require planning permission depending on the size and location.
Typical timeline: 10 to 12 weeks.
4. Mansard Conversion
The most extensive type of loft conversion, a mansard alters the entire roof structure to create an almost flat roof with steeply sloping walls. This provides the maximum amount of usable space and effectively creates a full additional storey.
Best for: Properties in urban areas where maximum space is the priority. Common in London terraced houses.
Planning permission: Almost always requires planning permission due to the significant change in roof structure.
Typical timeline: 10 to 14 weeks.
Key Considerations Before You Start
- Headroom: Minimum 2.2m at the highest point is recommended
- Structural assessment: Your existing structure needs to support the additional load
- Staircase placement: You need a safe and compliant staircase route
- Fire safety: Building regulations require proper fire escape routes
- Party Wall Act: If your loft conversion affects a shared wall, you may need a Party Wall Agreement
Get Expert Help from QM Designs
Our architectural team specialises in loft conversion designs across the UK. We assess your property, recommend the best conversion type, and produce all the drawings needed for planning and building regulation approval. Request a free quote today.
