Rear Extensions

Extending into the garden to create larger kitchen, dining or living space

A rear extension is the most straightforward and common direction to extend, building outward into the garden from the back of the house — and how far it can extend, and how it connects to the existing rear rooms, are usually the two biggest design decisions.

Extending to the rear is generally more straightforward from a design perspective than side or wraparound extensions, since it works with a single boundary direction rather than negotiating around an existing outrigger or side passage. Permitted development rights set out how far a rear extension can project without needing full planning permission, with different limits applying depending on whether the extension is single or two-storey and whether the property is detached, semi-detached or terraced — this varies enough by property type and history that it's always checked individually rather than assumed. The connection to the existing house is where the design work concentrates: whether the extension opens fully into the existing kitchen and dining rooms to create one continuous open-plan space, or is designed with some separation retained between old and new, and how much glazing — full-width bi-fold or sliding doors versus more traditional windows — connects the new space to the garden beyond. Roof design for a rear extension is also a significant decision, whether that's a flat roof, a pitched roof matching the main house, or increasingly a combination using a lantern rooflight to bring more natural light into the centre of a deeper extension where a standard flat roof alone would leave that area relatively dark.