Home Extensions in Brighton & Hove

Seamless, fully-managed house extensions designed to maximise space, flow, and value — trusted since 2006

Get a Free Home Extension Estimate
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What’s Included in Our Home Extensions

Single & Double Storey Extensions

Expand your home vertically or to the rear with structurally sound, planning-compliant additions tailored to your needs.

Planning & Design Coordination

We manage architectural planning, drawings, and permissions to keep your extension project stress-free.

Full Build Management

From foundation to final fix, our team oversees every phase with clear communication and workmanship guarantees.

Structural Modifications

We handle steelwork, RSJs, wall removals, and integration with the existing property layout for seamless results.

Interior Fit-Outs

Full internal finishings — including flooring, plastering, lighting, and heating — to make your new space move-in ready.

Building Control & Certification

We ensure compliance at every stage, liaising with inspectors and delivering full sign-off for your peace of mind.

Rainbow Building Plumbing & Electrical Services place picture
Rainbow Building Plumbing & Electrical Services
5.0
Based on 34 reviews
review us on
Peter W. profile picture
Peter W.
1 month ago
Large External Painting and Decoration & Maintenance Competitive price, with fast and efficient work. Have used them for many years and will use again.
Justin M. profile picture
Justin M.
2 months ago
We engaged Rainbow to renovate our shower room. Very, very easy to work with - helpful with advice and support about what we needed to get done. Mark and Max were great - you couldn't ask for friendlier people. We had some teething issues (NOT the fault of Rainbow) which Rainbow helped to rectify and get the job complete. Recommended and we'd certainly use their services again.
Tina W. profile picture
Tina W.
7 months ago
The contractors were extremely professional and prompt. They explained everything they were doing throughout the process and I am extremely pleased with the quality of the work
Clara G. profile picture
Clara G.
8 months ago
We went to Rainbow building to get some work done in our kitchen before we could get a new kitchen fitted in. They did wonderful work and let us know of any issues or complication we would face. Mark and Max especially were really nice and we're really happy with the partial wall removal, tile removing and replastering work they did for us!
Louise P. profile picture
Louise P.
9 months ago
Great communication, friendly team. Flexible when I had delivery delays.
Dan G. profile picture
Dan G.
10 months ago
The Rainbow team first did some excellent work for us 10 years ago. And they have just finished some renovations in the last week, which has gone really smoothly. Kev is a great communicator, always able to offer his expert opinion on the work required and then gets the job done. The best in Brighton.
Graeme C. profile picture
Graeme C.
10 months ago
Needed a complete flat refurbishment to include new Kitchen, Bathroom, Flooring, Electrics, Plumbing and Decorating etc. Wanted a local contractor to take control of the whole project rather than trying to juggle lots of different Trades myself. Rainbow (Mark in particular) were able to manage the whole project from start to finish and totally transformed the place, as shown in the photos. I was particularly impressed with the Kitchen so a special shout out to Stephen
Johanna D. profile picture
Johanna D.
11 months ago
We had a great experience with Kev, Mark and their team. Our bathroom was gutted and then totally refitted, and the result looks brilliant! They were really communicative throughout the process, offered recommendations, and worked hard to resolve issues which popped up. Would definitely recommend. Thanks so much!
Daryn C. profile picture
Daryn C.
12 months ago
We’re absolutely delighted with our new bathroom. Kevin, Mark and the team transformed an old, tired space into a clean, modern and relaxing room that’s a real joy to use. There were a few unexpected challenges along the way, but everything was clearly explained and managed, so there were no nasty surprises with the budget. They were also very considerate of our circumstances at home, which made the whole process much easier. Professional, tidy, and great communication throughout – highly recommended!
Manda S. profile picture
Manda S.
1 year ago
Steel Beam Works / Plastering / External Render / Carpentry / Window Fitting We have used Rainbow several times over the years and always had excellent workmanship. This was our biggest work and we were a bit nervous but Mark and the boys were extremely capable, curteous and considerate. We were living on site and they did their best to mitigate dust affecting our living area. We also didn't have to endure a radio playing the same music again and again! They were also very reliable. Now they have gone, we actually miss them!
Rowan B. profile picture
Rowan B.
1 year ago
Another fantastic job completed at the property, this time a new kitchen fit. Mark, Kev and the wider team were fantastic every step of the way - very responsive and amazing attention to detail. Would highly recommend their services.
Stephen F. profile picture
Stephen F.
2 years ago
Good
emma L. profile picture
emma L.
2 years ago
Friendly, reliable and willing to take on smaller jobs as well as larger ones. The work was of a high standard and communication was clear and simple. I wouldn’t hesitate to happily recommend Rainbow and will certainly use them again in the future.
Tilly U. profile picture
Tilly U.
2 years ago
From the very first on-site meeting with Kevin Viney at Rainbow Building Plumbing & Electrical Services we were confident in the advice given, and suggestions made. Major building renovations are a daunting task, so with Rainbow we felt we would be in safe hands if we engaged them. And we weren’t disappointed. Throughout the project those things that were most important to us were achieved, many requiring precision down to the millimetre. And when unforeseen issues arose, as they do in older buildings, whilst these caused us some sleepless nights, Rainbow confidently dealt with them enabling us to return to calm and carry on. Mark Burns, the builder and project manager, has been amazing with his wide knowledge, craftsmanship, and meticulous attention to detail - and his calm manner under pressure, has resulted in every aspect of the work carried out by Rainbow to be of a high standard and the best it could be. Thank you Rainbow - and if ever we are crazy enough to embark on another renovation project we would definitely be calling you to see it through.
John L. profile picture
John L.
2 years ago
Rainbow have carried out a complete refurbishment of my flat to an impeccable standard. They also landscaped the garden. Both look unrecognisable and I wouldn't hesitate to recommend Kev, Mark, Steve and the others at Rainbow.
Photo from customer reviewPhoto from customer reviewPhoto from customer reviewPhoto from customer reviewPhoto from customer review
Danny M. profile picture
Danny M.
2 years ago
Hi there - we have just had our kitchen fitted by Rainbow, and I would heartily recommend them to anyone else in Brighton. They were super organised, friendly and easy to communicate with, got the job done quickly AND it looks really good! Definitely good value for money as well! Cheers Danny
Teresa L. profile picture
Teresa L.
2 years ago
A trustworthy and responsive Building Company? Yes, it is rare but Rainbow fits the bill. Kev and his staff/contractors know their stuff. Kev was always responsive and reliable when contacted - a big plus in my book - and his workers left the place as clean and tidy as possible after a major structural work. Definitely recommend
andy B. profile picture
andy B.
2 years ago
I have nothing to say bad about these guys - Kev and his team are awesome they did an amazing job of knocking through out kitchen and dining room - putting in new steels and installing a new kitchen - Mark was project manager and i have not met a nicer guy who talked us through every step of the way Gary the plumber was amazing - Steve the Carpenter was utterly brilliant - and Danny the tiler super quick and awesome :) would def recommend to anyone - plus getting them back to do our new bedroom and ensuite later this year :)
Claude L. profile picture
Claude L.
3 years ago
Went above and beyond will always use again
Aliénor D. profile picture
Aliénor D.
3 years ago
My go to guy as of now . Boiler swapped in one day for cheap

Need Extra Space at Home?

Whether it’s a growing family or changing needs, a home extension can give you the room you need — beautifully designed and expertly built by Rainbow.

Get a Free Home Extension Estimate

Why Clients Trust Rainbow for Home Extensions

🏠

Full-Service Extension Experts

From initial designs to final sign-off, we handle every part of your home extension with care and experience.

📏

Detailed Planning & Advice

We coordinate with architects and engineers to make sure your extension meets both your vision and all regulations.

🧱

Seamless Build Integration

We match materials, finishes, and structure to blend your extension perfectly with your existing home.

When You Might Need This

You need more space for a growing family or new lifestyle needs
You want to increase your home’s value before selling
You’re adding a kitchen-diner, utility room, or extra bedroom
You prefer extending instead of moving to a new house
You want better flow between indoor and outdoor areas
You need help managing permissions and planning applications

How We Work

1

Request Your Estimate

Hit "Get a Free Estimate" to tell us about your home extension goals and book your consultation with our team.

2

We Visit Your Property

We assess your space, discuss your vision, and review planning or layout possibilities for your proposed extension.

3

Receive a Detailed Estimate

You'll get a full written quote outlining phases, materials, and pricing — with no hidden extras.

4

Build Gets Underway

We begin the work as agreed — efficiently, respectfully, and in full compliance with UK building regulations.

📋 Important: Required Documentation for Accurate Estimates

To produce an accurate estimate, all three of the following latest versions of the documentation must be provided, along with their associated version numbers, project/drawing numbers, and dates:

  • Latest Architect drawings (must include Version number or Drawing/Project number, and Latest Date).
  • Latest Structural drawings (must include Version number or Drawing/Project number, and Latest Date).
  • Latest Building / Materials notes or drawings (normally found attached to the Architect drawings or on separate notes; must include Version number or Drawing/Project number, if applicable).

Thinking About Extending?

If you’re planning to stay but need more room, we’ll help bring your home extension ideas to life — with clear pricing, smart design, and experienced trades.

Book Your Free Home Extension Estimate

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Useful Links for Home Extensions in Brighton & Hove

Home Extension FAQs

Do I need planning permission for a home extension?

It depends on the size and location of your extension. Many projects fall under permitted development, but we'll help confirm what applies in your case.

How long does a typical extension take to complete?

Most single-storey extensions take 8–12 weeks. Larger or more complex builds may take longer — we'll provide a detailed timeline in your estimate.

Can you manage the design and planning process?

Yes. We collaborate with architects and engineers to support planning applications, structural calculations, and building regulation compliance.

What's included in the estimate?

You'll receive a detailed, fixed-cost estimate including materials, labour, timelines, and project management — with no hidden extras.

What documents are strictly required before an estimate can be produced and agreed?

To produce an accurate estimate, all three of the following latest versions of the documentation must be provided, along with their associated version numbers, project/drawing numbers, and dates:

Latest Architect drawings (must include Version number or Drawing/Project number, and Latest Date).

Latest Structural drawings (must include Version number or Drawing/Project number, and Latest Date).

Latest Building / Materials notes or drawings (normally found attached to the Architect drawings or on separate notes; must include Version number or Drawing/Project number, if applicable).

How do I get started?

Request a free estimate and we'll book a visit to assess your project, discuss your goals, and prepare a detailed proposal.