This type of addition will add space and value to your home. From design tips to rules and regs, Rebecca Foster explains the key factors to think about before going ahead

If you’re undertaking a loft conversion, incorporating a dormer extension as part of the works is a smart route to boosting the space and headroom. Positioned within the slope of the roof, this type of vertical addition is ideal for expanding urban properties without gobbling up precious garden amenity. Plus, it’s usually straightforward to achieve without having to apply for planning permission.

Design possibilities

Dormer windows come in an array of shapes or sizes, so selecting the style that works best with your home is important. “This type of extension is hard to categorise in terms of size – it can be anything from 1m to 10m wide, depending on the house,” says James Bernard, director at Plus Rooms. “A minimum internal head height of 2m is a good rule of thumb to justify a dormer addition. From there, you can incorporate glass doors, Juliet balconies or even a sliding entrance with a glass balustrade.”

BROTHERT ON LOCK

Inglis Badrashi Loddo Architects are the brains behind this plywood-lined loft conversion. The large dormer window invites plenty of sunshine into the space, as well as opening up great views of the garden and beyond