The Art of the Side Return Extension

This classic way of improving a terraced and semi-detached home – usually for a new kitchen – is a recipe for disaster if not designed properly. Charlie Luxton advises.

The side return extension is one of the most common domestic building projects. The millions of terraced houses that define so much of our urban landscape are ripe for this addition, but side return extensions need to be thought through properly. Get it wrong and this ‘improvement’ is not just disappointing, but can damage the light, flow and quality of your existing space rather than improve it.

The terraced and semi-detached home is in many ways a fantastic piece of design that provided good-quality, well-lit living space with sublime efficiency. However, the basic design is over 200 years old and in many ways reflects a bygone social structure with smaller separate rooms and perhaps, most problematically with today’s living habits, separate kitchens usually stuck out in the rear outrigger away from the main living space. The side return extension is the answer — and here’s how to get it right.

Design Style

One of the big questions with a side return extension is whether to complement or contrast with the existing house. Both work well and while there are no hard and fast rules, the best approach is to think about the kind of new space you want from your extension. If you are trying to radically alter your interior space, knocking down walls and making big openings for inside/outside living, then clearly this is very different from the existing space in an old terrace. If you are doing this then I think you should contrast the design, expressing a new stage in the building’s life. If however you are proposing smaller French doors and maintaining (but subtly altering) the existing layout, then a more sympathetic ‘in keeping’ design can work. I just get disappointed when I see massive bi-fold doors rammed into a traditional-looking house — it looks incongruous, unsubtle and usually wrong.

Natural Light

Doing away with the separate kitchen by infilling the narrow strip of the garden adjacent to the house and squaring off the floorplan to create a larger kitchen dining room makes a lot of sense. It is often the only possible way of extending the house, but in doing so you can create new space at the expense of daylight penetrating the middle of the house. A large part of the genius of the terraced house design is that the only area that doesn’t usually get good daylight is the stairs. Putting on a side return extension can plunge one of the main rooms into darkness, making it far less usable — you will need to be creative with rooflights, ceiling levels and artificial light to keep the quality of space. One option is to embrace the dark and create an intimate internal room for the evenings that is the Ying to the bright kitchen diner’s Yang, or an alternative is to move toilets and utilities – rooms that do not need so much natural light – to the centre of the house.

Ceiling Heights

A side return extension nearly always requires walls to be knocked down and there is always a temptation to take the easy route when doing this and simply put a steel beam under the joists of the existing floor above to support the rest of the building. This structure is then boxed in to create what the trade calls a ‘downstand’ — learn the name and learn to avoid it at all costs. This is because even though the wall has gone, the residual downstand has a big impact on creating the feeling of a new large single room. It divides the room, stops space flowing and makes the ceiling feel low and heavy. If you have very high ceilings you can design your way around a downstand. But for nearly all situations, go to the extra expense of pushing the new structure into the depth of the floor above and losing it. If you have to cut back on the cost of the kitchen and fit out, do so, as this can be easily improved at a later date — fiddling with the structure can’t.

To increase the sense of space in your new side return extension, try and create taller and/or vaulted ceiling heights in the new area that contrast with the old. This will draw the eye upwards and make even a small increase in space feel much larger.

Get the Pipes Right

Often the rear courtyard of the terrace has, over the years of retrofit and upgrading, become something of a spaghetti junction of services and plumbing. There are often manholes, waste downpipes, rainwater downpipes, etc. One of the first jobs in designing your scheme is to get a handle on how you are going to adapt the plumbing to allow for your new extension to shine. The alternative is boxed-in downpipes squeezing already narrow spaces, big ugly removable manhole covers smack bang in the middle of a new floor, and ugly waste pipes snaking around the roof of your pride and joy — I have seen it all.

The Right Approach

A well-designed, well-built side return extension can give a home a new lease of life, bringing it perfectly up to date for contemporary living. Like everything in building it needs to be properly thought through — so make sure you get the fundamentals right before you get carried away with the finishing touches.

Archives
  • We’ve been shortlisted in the Wood Awards 2026! - We are very excited that our Headquarters for an Ethical Finance Company has been shortlisted in the Buildings category of this year’s Wood Awards! We are incredibly proud of this project and all the teams involved, not least our wonderful and supportive clients. Built around regenerative
  • Conservation of 16C Roof Structure - An amazing discovery was made during the works on site at a pub project we’re currently working on. Careful removal of layers of plasterboard inside an outbuilding has revealed a mid-sixteenth century roof structure over a section of the building.
  • Grade II Listed House in Homes & Gardens - Of all our projects, this one has been featured the most in press over the years. It can be found in this month’s Homes & Gardens magazine as an example of a modern extension to a period farmhouse. A sensitively
  • A Cotswolds House - We are very pleased to have had a recently completed project photographed. The owner’s of the house came to us for help to reconfigure a relatively new building. The brief was to create a home that could expand and contract
  • Charlie x Retrouvius for their new blog, Taking Stock! - Our founder Charlie was invited by our friends at architectural design and salvage company, Retrouvius, to be the first guest on their new blog series, Taking Stock. Charlie sat down with Adam to talk about the importance of using salvaged
  • Visiting a project on site - We are in the final weeks of construction for this barn conversion project. We are combining an original stone barn with two agricultural barn structures to provide a home for a growing family. A clear attention to detail has been
  • Photographing Day - We recently visited a completed project which is now ready for photographing. It’s always a pleasure to return to a building and its owners who we have got to know so well. Looking forward to revealing the final images when
  • Headquarters for an ethical finance company - This project is the new headquarters for an employee-owned ethical finance company, built around regenerative architecture and circular economy principles. An almost entirely timber structure was constructed within two existing steel-frame agricultural barns, retaining as much of the original fabric
  • Ridgeway House wins a RIBA South Award! - We are so proud that Ridgeway House has won a RIBA South Award! The success of the project is testament to our amazing team, and to the wider team who were involved. The competition was very strong which makes winning this award
  • Pre-cut timber I beam system - As part of our commitment to sustainability, we have refined an in-house, pre-cut timber frame system over the past decade, aimed at improving affordability, construction efficiency and environmental performance. Having worked with numerous timber frame suppliers in the past, we
|