Wraparound and side return extensions

What each type is

A side return extension fills the narrow strip of land beside the house, often a passage alongside a rear outrigger on a Victorian or Edwardian terrace, or the gap between a semi and its boundary. Infilling that strip widens the kitchen or living space behind the front rooms.

A wraparound extension combines a side return with a rear extension in an L-shape that wraps around the back corner of the house. It creates the largest single space, usually a kitchen, dining and family room, but it is also the most involved to design and approve.

Which houses suit them

Terraced houses with outriggers are the classic candidates for a side return. Semi-detached houses with a side passage suit both types, and detached houses with space to the side can take a wraparound comfortably. The key factors are the width of the side strip, the position of drains and boundary walls, and how the new space will connect with the existing rooms.

Why a wraparound needs planning permission

Lee's summary of the permitted development limits for single storey rear extensions is clear:

Single-storey rear extensions: 3m for attached properties and 4m for detached properties. Extensions cannot be attached to any existing extension or be a wrap-around extension. For all Permitted Development extensions, the materials and external finish should match the existing property.

Because a wraparound joins a side and rear extension into one, it falls outside permitted development and needs a householder planning application. A side return on its own may sometimes be permitted development, but there are limits on width, height and position, and it cannot face a road. Our guide on whether you need planning permission for an extension explains the routes.

Light, rooflights and boundary walls

The biggest risk with a side return is a dark middle room. Infilling the side strip can cut off the window that used to light the kitchen, so the new roof has to bring light back in. Rooflights, a glazed strip along the boundary wall or a continuous glazed roof over the side return are common solutions. Getting the glazing right is usually what makes these extensions feel open rather than cave-like.

Building along a boundary also raises the height of the wall facing your neighbour. Councils look closely at that height and at the effect on the neighbour's light and outlook, so the roof form along the boundary is often kept low, with the roof sloping or stepping up away from the shared edge.

Party walls

Side returns and wraparounds often involve building on or close to a boundary, or excavating near a neighbour's foundations. The Party Wall etc. Act sets out a process for notifying neighbours before that kind of work. It is separate from planning and building regulations, and it is sensible to consider it early in the design.

Steel and structural openings

Opening up the side and rear of a house to create one large space means removing load bearing walls, often at the back corner, where loads from the floors and roof above come together. That usually needs steel beams, sometimes with a steel post or a goalpost frame, and new foundations under the extension walls. These elements are designed by calculation and shown on the drawings, which is where our structural calculations and drawings service comes in.

Planning considerations for neighbours

Beyond the boundary wall, the main concerns are usually overshadowing of neighbouring windows and gardens, overbearing walls along the boundary and any overlooking from new roof glazing. A thoughtful design, shown clearly on the drawings, answers these points before they become objections. We also look at how the extension will appear from the street, especially on corner plots.

If you are considering a side return or wraparound, our house extension plans page explains how we work, starting with a free on-site consultation with no-obligation quotation.

Recent jobs

• Rear side infill extension (Winchester)
• Wrap around porch, garage and utility space (Winchester)

Frequently asked questions