How to plan a wraparound home extension

Combining a rear and side extension requires specific planning and research, but can pay dividends in adding space to your home.

By Paula Woods | 11 May 2020

Extending into a side return and at the rear of a property creates a generously sized L-shape space, but comes with its own challenges.. Here’s what you need to know.

Image: Brian O’Tuama Architects has used a structural steel frame to transform a once inefficient layout into a large, extended, single internal space. Overhead structural glazing and industrial-style, slim metal Mondrian doors by IQ Glass flood the new interior with light.

Rear extensions and side return extensions are both popular choices for those seeking to add more space to their home.

If you have the space, you can also choose a complete wraparound extension, creating an L-shape addition which will make the room longer and wider – perfect for modern, open-plan living.

A wraparound extension is, however, more than a sum of its parts, and needs to be considered differently to a side and rear extension. Here are the key differences you should consider.

Planning permission

Image: Darren Oldfield Architects designed this contemporary, zinc-clad wraparound extension.

A wraparound will always require planning permission. ‘Under permitted development you can extend along the side and separately at the rear, but the two cannot be joined together to form a wraparound extension unless permission has been granted,’ explains Darren Oldfield, director of Darren Oldfield Architects.

Some local authorities even have a policy that doesn’t allow wraparounds, although perceptions are gradually changing and different planning departments may interpret the guidelines in their own way. Planners will want to see that neighbours won’t be unduly affected, especially in regards to light and privacy. Consequently, two-storey wraparounds are highly unlikely to be granted permission on terraced homes, and, even on single-storey extensions, you may find restrictions are placed on size and height. ‘The pre-application system is a great way to determine what would be possible and to open a dialogue with the planners,’ suggests Robert Maxwell, director of Maxwell & Company London.

Extending into a side return and at the rear of a property creates a generously sized L-shape space, but comes with its own challenges.. Here’s what you need to know.

wrap around extension with glazed skylights - grand designs

Rear extensions and side return extensions are both popular choices for those seeking to add more space to their home.

If you have the space, you can also choose a complete wraparound extension, creating an L-shape addition which will make the room longer and wider – perfect for modern, open-plan living.

A wraparound extension is, however, more than a sum of its parts, and needs to be considered differently to a side and rear extension. Here are the key differences you should consider.

Planning permission

darren oldfield wrap around extension with glazed side return – grand designs

Image: Darren Oldfield Architects designed this contemporary, zinc-clad wraparound extension.

Building a team

Maximise your chances of obtaining planning permission by hiring an architect to both design and submit the project for planning. A good architect will have experience of planning policy and be able to make suitable changes should the local authority suggest these are a requirement for approval. Your architect may also be able to recommend a main contractor or oversee more complex builds, although on smaller extensions your builder is likely to take on this role; or you might consider acting as project manager yourself.

A wraparound involves the removal of the original side return and back rear wall, and there are a number of ways this can be achieved. All require steel supports in the form of beams and posts, for which structural calculations and engineering plans will be required.

Glazing

De Rosee Sa Blue House Exterior 02 Alex James Photography

Image: An earlier rear extension was rebuilt and widened by pushing out into the side return to enable architect De Rosee Sa to create more usable internal space in this home.Photo: Alex James

Consider how you are going to achieve good levels of daylight without risking overheating. Effective glazing should take into account site orientation and surrounding buildings, rather than resorting to expensive, highly insulated glass or reflective coatings.

Any room that loses its window due to the construction will suffer from poor daylight, so ensuring there are good amounts of overhead glazing is crucial. Bear in mind that the most import area of glazing for wraparounds is the side elevation. Otherwise, the area closest to the original rear elevation can become quite dark and gloomy.

Exterior styles

Proctor and Shaw Architects folded house dark clad exterior extension - grand designs

Image: Architect Proctor & Shaw included a picture window in this wraparound extension on a south London property.Photo: Ståle Eriksen

‘Planning may play a part in your selection of materials, as sometimes there are stipulations to match the new architecture with the existing – and sometimes the exact opposite,’ says John Proctor, director at architect and design studio Proctor & Shaw.

Wraparounds also offer an opportunity to distinguish between the front and side additions. For example, the side return could be all glass, while the rear area could be glazed brick or timber. This approach can help retain a sense of the original footprint, as can stepping back a section of the new rear elevation to mimic the old.