Side Return Extensions

The side passage itself is often only a metre or two wide, so the floor area added is modest. The difference it makes is much bigger. Removing the wall between the passage and the kitchen changes a narrow galley into a room wide enough for an island or a dining table, with light coming in from above.

How much you gain depends on the width of the passage and the length of the rear wing. If you want to add space at the back as well, a wrap-around extension combines a side return with a rear extension in one L-shaped build.

• Glazed roof: A fully or partly glazed roof floods the new space with light. It suits the long, narrow shape of a side return.
• Solid roof with rooflights: A flat or pitched roof with roof windows gives more insulation and a more even temperature, with plenty of light.
• Roof shape: A sloping roof that stays lower at the boundary helps with planning and with the neighbour's light. A flat roof gives a cleaner, more modern look.
• Rear doors: Sliding or bifold doors across the back open the kitchen to the garden.
• Heating: underfloor heating installation keeps the walls clear for units and works well under large areas of glass.

To open up the kitchen, the old side wall of the rear wing is removed and replaced with steel beams, designed by a structural engineer and supported on padstones. New foundations are dug for the boundary wall of the extension.

Side returns often have drains running down them, including a soil stack, gullies or an inspection chamber. Before the design is finished, we check the drains with a CCTV drain survey. If they need moving, our drain installation and replacement team reroutes them. If the extension is built over or near a public sewer, a build over agreement from the water company may be needed.

It depends on the design. A side extension on a house in England can be permitted development if it meets these conditions:

• Single storey: It is no more than 4 metres high.
• Near the boundary: Any part within 2 metres of the boundary has eaves no higher than 3 metres.
• Width: It is no wider than half the width of the original house.
• Materials: It looks similar to the existing house.

In practice, many side returns need a planning application, or at least a Lawful Development Certificate. This is because the roof rises above the boundary wall, the extension also extends at the rear, or the house is in a conservation area or covered by an Article 4 direction. Flats and maisonettes always need permission. We check the route for your house at the survey and prepare the drawings.

Usually, yes. A side return is normally built along the boundary with your neighbour. The following all need a notice under the Party Wall etc. Act 1996:

• building a new wall on or astride the boundary
• raising or thickening the existing garden wall
• digging foundations within 3 metres of the neighbour's house to below the level of its foundations

If your neighbour agrees, work can go ahead. If not, a party wall surveyor prepares an award. We tell you which notices are needed at the survey and allow time for them in the programme.

Every side return extension needs building regulations approval, covering:

• foundations and the steel beams
• insulation and glazing to energy standards
• drainage
• ventilation
• fire safety
• new electrical circuits

Building control inspects the work at key stages and issues a completion certificate at the end.