A loft conversion is your best option to gain space without moving house or building an extension. We’ve put together a rundown of the most common types of loft conversion so you can see what’s involved.  

First, think about how to use the space you’ll gain from this home renovation. Additional bedrooms and bathrooms are always desirable and add value to your home, but these days you might prefer a kids’ playroom or home office far away from other living areas.  

In general, a loft conversion will cost between £35,000-£50,000 and take 8-12 weeks depending on the purpose and amount of structural work required. Talk to your contractor to see which type of loft conversion is best for your needs, budget and type of roof. 

5 Types of Loft Conversions

Options and pricing start with simple internal loft conversions, followed by various types of dormer and full roof-removal-and-build conversions, which will give you anything up to a whole additional floor with price tag to match.  

1. Roof Light Loft Conversion

This internal attic conversion is most straightforward, least disruptive and cheapest (up to 25% less than other conversions). It’s also least likely to require planning permission as it doesn’t involve altering or expanding the existing roof shape or volume. 

If you have at least 2.25 m head height in the centre of the room, just add skylights, a reinforced floor, insulation, plasterboard and plaster it to create a usable living space.

On the downside, roof light conversions provide the least amount of usable space and are less versatile than other options. Adding desirable features like an en-suite bathroom may be more tricky, and you’ll need to be clever about using the eaves for storage to make the most of awkward space.  

A simple roof light conversion should cost £16,000 - £22,000 and take 6 to 8 weeks. 

2. Dormer Loft Conversion

Dormers come in all shapes and sizes, from the classic single or double windows to larger constructions running almost the length of the roof. All create a good amount of extra space, headroom and light by installing vertical walls, windows and a flat ceiling. There’s a dormer to suit every style of home and they’re a good return on investment for relatively simple construction work. 

Dormers are usually added at the back and may come under Permitted Development Rights but you can apply for planning permission to add them at the front and sides. 

Depending on the number, style and size, a dormer loft conversion will cost £50,000 - £80,000 and take12 to 16 weeks. 

3. L-shaped Loft Conversion

This is technically another type of dormer. If you have an L-shaped house, you can add a dormer to each wing and connect them up to create lots of headroom and space, almost the equivalent of another floor. Depending on the size of your house, you may even be able to create multiple rooms up there. 

4. Hip to Gable Loft Conversion

If you have one end of a sloping roof free, a hip-to-gable loft conversion replaces that ‘hip’ end with a vertical ‘gable’ side wall. Hip-to-gables work on detached and semi-detached homes and bungalows, can be used to extend a previous roof light conversion or combined with a rear dormer for maximum space gain. 

Of course, this type of loft conversion is more complex and expensive than previous options as it involves removing and rebuilding part of the roof, which usually requires planning permission. However, it’s still better value for money than building a ground floor extension. 

5. Mansard Loft Conversion

Mansard loft conversions are the most complex as they involve replacing one entire length of a sloping roof with a flat roof and almost vertical wall. For this reason, mansards are normally added at the back of a property and usually require planning permission and possibly a structural engineer. They’re the most expensive type of loft conversion but best for gaining space and light and work well on most types of home, including terraces. Mansards are also favoured by some London Borough Councils for being most in keeping with original properties in the area.  

Budget for £40,000 - £80,000 depending on the specifications, like if you add a bathroom or balcony. Plan for 16 to 20 weeks for this loft conversion.