Maximise unused space
A side extension turns underused side-return or alley space into valuable interior living space without taking away a large part of your garden.
London side extension specialists
Side Extensions London
Expand your home sideways with a bespoke side extension designed to add space, natural light and better flow without sacrificing valuable garden space.
Londonside extension specialists
Designlight-filled layouts
Buildmanaged construction
Freequote and project advice
Bespoke home extensions
Side Extensions London – expand your home with expert design & build
A side extension intelligently uses the unused alley or side-return space of your home.
Our London side extension specialists design and build custom side extensions to expand your living area, often enlarging the kitchen, dining area, living room or adding a new practical room. This type of extension can improve the overall layout of your home while adding natural light and valuable floor space.
We help homeowners across London create side-return extensions, single-storey side extensions, kitchen side extensions and tailored side additions that feel like a natural part of the original property.
- Side-return extensions for London terraces and period homes
- Open-plan kitchen, dining and living spaces with improved light
- Planning, permitted development and Party Wall support
- Complete design & build service from one experienced team
Why choose our London side extension service?
More space, better flow and smarter use of your home
Side extensions are especially useful for London homes with unused side-return space. They can transform narrow kitchens, dark rooms and awkward layouts into bright, practical living areas.
Improve natural light
Skylights, roof lanterns, glass doors and wide openings help bring daylight into the centre of the home and make compact spaces feel larger.
Add property value
A well-planned side extension can improve future resale appeal by creating a larger kitchen, better layout and more flexible living space.
Tailored design
Your extension can be designed as a kitchen-diner, home office, utility room, playroom, garden room or improved family living area.
Our services
Side extension design, planning and construction
We provide a complete service for side extensions in London, covering early advice, design, planning, Building Regulations, structural work, construction and finishing.
Side extension design
We design practical layouts that maximise light, improve movement through the home and make side-return spaces feel open and useful.
Side-return extensions
Perfect for London terraced homes, side-return extensions can widen a narrow kitchen and create a brighter open-plan kitchen-diner.
Planning & permitted development
Many side extensions can fall under permitted development when they meet height, width and single-storey rules. We check the correct route before you commit.
Party Wall support
Side extensions are often close to neighbours. We advise on likely Party Wall requirements and help keep the process organised.
Building Regulations
We coordinate structural calculations, Building Control drawings, insulation, drainage, electrics and other compliance requirements.
Construction & finishing
Our builders and project managers take the approved design through construction, fit-out, finishing and handover.
Planning & regulations
Planning permission, permitted development and Building Regulations
Many homeowners are relieved to learn that some single-storey side extensions do not require a full planning application when they meet permitted development rules. However, the limits must be checked carefully.
A typical permitted development side extension must be single-storey, no taller than 4m, no wider than half the width of the original house and built with materials that are similar in appearance. If the property is in a conservation area, affected by Article 4 restrictions, listed, or the proposal goes beyond the rules, planning permission may be required.
- Permitted development checks for side extensions
- Planning applications for larger or sensitive projects
- Building Regulations and structural calculation coordination
- Party Wall guidance for London terraces and close boundaries
Our process
How we deliver your side extension
We use a clear step-by-step process so your project stays organised, from first survey to final handover.
Consultation & survey
We begin with a free site visit, discuss your requirements and survey the property to understand access, boundaries, layout and planning considerations.
Design & planning
Our design team creates plans that maximise light and flow. We also manage planning submissions, permitted development checks or Lawful Development Certificate advice.
Structural & regulations
We coordinate engineering calculations and Building Control drawings so the extension is structurally safe and compliant.
Construction
Our skilled builders construct the side extension and keep you updated through foundations, structure, roof, glazing, services and internal works.
Project management
A dedicated project manager keeps trades, materials and communication organised so the project runs smoothly.
Completion & handover
We complete finishing, snagging and final checks before handing over your new side extension.
High-quality design & construction
Side extensions built for London homes
Small side spaces can feel much larger when the design uses the right glazing, roof form, layout and materials. We focus on practical design details that make your extension work beautifully every day.
Open-plan layouts
Create wider kitchen-diners, better circulation and a stronger connection between cooking, dining and relaxing areas.
Skylights and roof glazing
Bring light into the side-return area and improve darker parts of the home.
Quality materials
Brick, render, glazing, flooring and roofing details are chosen to complement the existing property.
Fixed price clarity
We provide transparent, itemised quotes so you understand the build scope before work begins.
Local experience
We understand London terraces, tight access, boundary issues and local planning expectations.
Turnkey support
Design, planning, regulations, project management and construction are coordinated through one team.
Cost guidance
Side extension cost in London
Side extension costs vary by size, structure, access, glazing, finishes and whether the project includes a full kitchen fit-out. Typical London side-return or single-storey side extension projects can start from around £30,000 and may rise significantly for larger or higher-specification work.
We provide clear, itemised quotations covering design, planning, structural support, construction and finishing so you understand what is included before making decisions.
- Clear written quote before work begins
- Advice on planning fees, Building Control and structural calculations
- Options for practical, mid-range and premium finishes
Project management
Managed from concept to completion
Side extensions need careful coordination between design, planning, structural engineering, Building Control, trades and finishing. Our project management approach keeps everything joined up.
You get a single point of contact, regular updates and a clear programme so the extension stays on track.
Questions homeowners ask
Side extensions London FAQs
How much does a side extension cost in London?
Costs vary by size, scope and finish. Many typical side-return projects start around £30,000–£65,000, but larger projects, premium glazing or a full kitchen fit-out can cost more. We provide a detailed quote after reviewing your property.
Do I need planning permission for a side extension?
Not always. Single-storey side extensions can qualify as Permitted Development if they meet rules on height, width, position and materials. Conservation areas, listed buildings, two-storey designs or larger proposals usually need planning advice or permission.
How long does it take to complete a side extension?
Once permissions and design work are ready, a typical single-storey side extension often takes around 3–4 months to build. The exact timeline depends on size, access, structural work and finish level.
Can you extend the side of my bungalow?
Yes, provided the layout, boundary position and planning rules allow it. Detached bungalows may often have good potential for single-storey side extensions, but every property needs a proper assessment.
What is a side-return extension?
A side-return extension uses the narrow strip of land beside a rear projection, commonly found on London terraced homes. It is often used to widen a kitchen and create a brighter open-plan kitchen-dining space.
How do I choose the right side extension builder?
Look for local experience, clear pricing, good reviews, examples of similar projects and a team that can manage design, planning, Building Regulations and construction together.
Can you handle Party Wall matters?
Yes. Side extensions are often close to neighbours, so Party Wall notices may be needed. We can advise on likely requirements and help coordinate the process.
Start your side extension
Request a free side extension quote
Tell us about your property, side-return space and the new room or open-plan layout you want to create. We will advise on design options, planning route, likely build stages and next steps.
- Free no-obligation first conversation
- Advice on design, planning and build feasibility
- Support with quotes, regulations and project management
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Complete the form and our team will contact you to discuss your side extension.
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Ready to expand your London home sideways?
Speak with our London team about your side extension, from early design and planning through to construction and handover.