Side return extensions
London architect guide
Inspiration and ideas
Side return extensions to houses and garden flats are a great way to add space on the ground floor where the kitchen and utility areas were traditionally placed.
At this early stage we encourage you to follow a three step process of thinking about the type of extension you want, considering some design aspects, and then looking for inspiration to cement your own ideas.
As part of this Side extensions London architect guide we have selected some projects to lend architectural inspiration and design ideas for your side return extension.
GOAStudio London residential architecture
George Omalianakis, BA (Hons) B.Arch Pg Dip Environmental Design.
Chartered RIBA architect and ARB registered.
RIBA Conservation Registrant specialism in conservation areas, period and Listed buildings.
Residential expert contributor for magazines including Which? magazine and Ideal Home.
Last reviewed by George Omalianakis for GOAStudio: August 2026
Muswell Hill Haringey N10 Side return kitchen extension_Breakfast bar area
Muswell Hill Haringey N10 Side kitchen extension by GOAStudio architects Through views
Locally listed house extension architects Two storey rear and side extension in High Barnet EN5 – Yellow and blue lights
Kitchen extension Highgate Conservation Area N6 House renovation and contemporary design by GOAStudio architects – Side light rear light
Dalston Junction Hackney side extension
Residential house extension and refurbishment Finchley Road Camden NW6 Contemporary architecture
For more advice and information see the following:
Royal Institute of British Architects (RIBA)
- Do I need an architect for my extension or home project?
- Why work with an architect?
- How do architects calculate their fees?
Planning Portal
Side return extensions London architect guide – Design aspirations and key considerations
One of the most common challenges in a full side return extension is that it will often result in blocking the light coming in from the door/window that exists at the rear part of the elevation.
The most common way of solving this is by allowing for rooflights to the new side roof.
The further back the rooflights are the better it is since natural light can reach deeper into the floor plan and help to define a new dining or kitchen area at the rear part of the house or flat.
Another good solution is to avoid building up to the rear door/window.
This creates the opportunity for what we describe as an ‘external room’, a landscaped courtyard between the existing house and the new extension.
Remember it is always possible to open up the wall between the front and rear reception rooms and bring light from the front room into the middle room while at the same time creating long views across the ground floor.
Side return extensions London architect guide – Types and options for your home project
Side Return House Extensions
Side return extensions can be either single storey (for reasons really unknown, they are often called “side returns”) at the side/rear part of the property, or double storey across the whole of the side part of the property.
Subject to planning approval, two storey side extensions often include the conversion of a garage on the ground floor and building on top of it to add more bedrooms and bathrooms to the existing first floor.
Lean-to Extensions
Lean-to extensions are small side extensions, often with a pitched roof that offers supplementary space to what used to be the utilitarian part of the house and where most kitchens are now located.
For single storey side extensions a key decision is about the roof profile.
Tiled or slated pitched roofs with standard rooflights tend to appear more in-keeping with the existing property, and they reduce the effect of the extension to the neighbouring property; such extensions can be fully glazed creating a contemporary feel to the new space added.
Flat roofs add a more modern feel and they tend to provide greater internal headheight and a more generous sense of space.
They can be fully glazed or partially glazed depending on cost, aesthetic preferences, and the position of any high level kitchen units in the area immediately underneath the roof.
Side return extensions London architect guide – Start here and design your side return extension
During the design development stage we will get to explore lots of ideas but you can start the process now by considering answers to questions as such:
- “Should we build to the boundary, or is it possible to retain access to the garden from the front of the property by building an extension that is less wide?
- “Is there a manhole cover in the side area, and what will happen to the existing drainage and soil vent pipes in this area?
- “How can we maximise the light from the side return extension, and should we go for a flat roof or a pitched roof?
- “How can we rearrange the kitchen, and will there be enough space for an island unit?
- “How will the second storey of the side extension relate to the rest of the first floor layout?”
- “Is there a bedroom on the ground floor that we wish to retain a window for, and should we go for a full side or a partial side extension?”
Read our guide for your single storey extension
Whether you want a spacious kitchen-diner, a light-filled family room, or better access to the garden, extending at ground floor level often provides the most cost-effective and planning-friendly way to improve how you live.
Read our guide for your double storey extension
Whether you’re adding a generous kitchen-diner on the ground floor with a new bedroom and bathroom above, or extending an entire wing for family space, a two storey extension makes better use of your site while maximising value and achieving construction efficiency.
Read our guide for your bungalow extension
Whether you need more natural light, better connection to your garden, or a flexible new bedroom or workspace, a carefully designed bungalow extension can help you stay rooted in the area you love while improving comfort levels and the layout of your home for the long term.
Read our guide for your wraparound extension
For terraced and semi-detached properties, especially in densely built areas, a well-designed wraparound extension allows you to rethink the entire ground floor adding floor area, improving flow, and connecting to the garden.
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Send over your address, a few photos, and a short outline of what you're hoping to achieve.
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Not sure where to start with your renovation or extension?
Read this before you meet an architect, speak to a builder or spend money on drawings.
This free, architect-prepared guide walks you through the 15 essential questions every homeowner should ask before starting a project.
"Should we renovate, extend… or walk away?
15 Questions every London homeowner must ask before starting a project to include homes in Conservation Areas and Listed Buildings."
Whether you're planning a modest rear extension or major alterations to a listed home, it will help you avoid expensive mistakes and give you clarity on what’s possible for your property. Includes guidance on:
Planning approvals. Conservation areas.
Timelines and costs. Appointments you need to make.
Design and sustainability options.
When to press ahead and when to walk away
We provide architectural services for residential projects in the following London Boroughs:
Barnet, Camden, Enfield, Hackney, Hammersmith and Fulham, Haringey, Islington, Kensington and Chelsea, Lambeth, Lewisham, Newham, Tower Hamlets, Waltham Forest, Wandsworth, Westminster
We specialise in
- Greener homes
- Retrofit and energy efficiency for older and traditional buildings
- Conservation areas
- Listed Buildings
- Homeowner architectural services
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GOAStudio London residential architecture limited.
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Chestnut Avenue South, E17 9EJ, Waltham Forest
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