Not all loft conversions are the same — and the right type for your home depends on your property's roof structure, your budget, your planning situation and how much space you need.
1. Dormer Loft Conversion — £45,000 to £65,000
Best for 1930s semis, Edwardian terraces and most North London property types. Usually Permitted Development. A box-shaped structure extends vertically from the existing roof slope, dramatically increasing headroom. The most popular loft conversion type across Barnet, Mill Hill, Whetstone and Totteridge. Works on the vast majority of North London property types and delivers excellent return on investment.
2. Hip-to-Gable Loft Conversion — £50,000 to £70,000
Best for detached and semi-detached homes with hipped roofs. Usually Permitted Development. Replaces the sloping hip end of the roof with a vertical gable wall, creating substantially more floor space and headroom. Common on detached and end-of-terrace properties across Barnet and Hadley Wood. Almost always combined with a rear dormer to maximise the overall space created.
3. L-Shaped Loft Conversion — £60,000 to £80,000
Best for Victorian and Edwardian terraced houses with rear additions. Usually Permitted Development. Places a dormer over both the main roof and the rear addition, creating a large L-shape. The go-to choice for Victorian and Edwardian properties across Hampstead, Highgate, Muswell Hill and Finchley. Often large enough for two bedrooms and a bathroom.
4. Mansard Loft Conversion — £65,000 to £90,000
Best for conservation areas and properties wanting maximum space. Always requires planning permission. Replaces the entire rear roof structure with a near-vertical rear wall and flat roof — the most spacious of all conversion types. Common in Hampstead and Highgate where planning restrictions may limit dormer options. We manage all planning applications.
5. Velux / Roof Light Conversion — £25,000 to £40,000
Best for properties with good existing headroom and tighter budgets. Usually Permitted Development. Skylights installed into the existing roof without altering its shape. Only suitable where there is already adequate headroom — typically 2.2 metres at the ridge.
Which Type is Right for My Home?
The best way to find out is a free site visit from our team. We'll assess your roof structure, discuss your goals and budget, and give you honest advice. Call us on 020 8441 3144 or try our Online Price Guide for an instant budget estimate.