Loft conversion: Dormer

There’s good reason why this type of home improvement is the most popular way to expand into your attic. Increase the headroom, usable floorspace, light and liveability at the apex of your house with this flat-roof, straight-wall extension.

Dormer loft conversion cost

Starts from £35,000

Naturally, the end cost of a dormer loft conversion is based on size, shape and finish, plus the current roof structure/pitch. If you choose an L-shaped version, the cost is around £15K more.

There are many aspects that make up the final cost to take into consideration. The structural work includes:

Construction of the “box”
Windows
Floor reinforcement
Staircase
Insulation
Additional skylights
Heat source
Electrical work
Plumbing pipework
Lighting
Built-in eaves cupboards
Safety measures

The decorative, cosmetic finish plus fixtures and fittings include:

Flooring: carpets/tiles/vinyl
Walls: painted/papered
Lights: shades
Bathroom: basin/tub/shower
Freestanding accessories: storage/furniture

Dormer loft conversion options

Want to expand to the side, rear, or both?
How will you use the space?

Many homeowners extend on the back of their property. To maximise space you can go further to create an L-shaped style too.

It takes on average six to eight weeks to complete building, then add on the finishing touches.

Dormer roof conversion planning permission

Significant home improvement work is much easier when it falls under Permitted Development. This project can do so, as long as it complies with certain requirements, such as:

Height not exceeding original roof
Square footage below a certain amount (semis/detacheds’ total is larger than terraces)
Neighbours unaffected (no overshadowing/overlooking)
No balconies (except Juliet style)
Materials match character of property

Even when all of these guidelines are met, you still need a Lawful Development Certificate.

Planning permission is necessary for those living in a designated conservation area and/or a listed building.

You also need to be sure the work adheres to Building Regulations. These include: