Extension Builders in Belsize

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4 (17 reviews)

Easily find verified Belsize Extension Builders. Just post your job to get quotes from MyBuilder's Extension Builders in Belsize.

Select a service

How it works

Post your job for free

Tell us about your job, and we’ll alert suitable tradespeople in your area. It’s simple and free.

Tradespeople respond

Once your job is posted, you’ll get responses from interested tradespeople through the website.

Review profiles and choose

Browse profiles, work history, and feedback, then choose who you wish to share your details with.

Some of our top rated extension builders in Belsize

3512 Results

Sort by:

P&A Building&Decorating
Rating: 5 out of 5
Extension Builder in Belsize
We offer a wide range of building and decorating solutions such as: Kitchens Bathrooms Plastering Roofing Flooring Painting Decorating Plumbing Including CORGI Gas Safety Electrics Including And NICEIC Certificate Extensions Loft Conversions. Warranty All Works Fully Guaranteed
Get in touch
Latest review:
Piotr ( Peter) has been trustworthy, reliable and very good value for money from the moment he started working on my flat. His work has been completed fast, with accuracy, and always leaving the surrounding area clean and tidy. I recommend him to my friends and am happy to give more references if required.
Sogut
No reviews yet
Extension Builder in Belsize
Company Description We are an experienced team providing high-quality building and home improvement services. We complete our projects safely, on time, and to standard building regulations. Our services include: • House extensions & garden rooms • Full house renovations • Roofing • Plumbing & electrical work • Wall & floor tiling • Door fitting • Porches & patios We deliver clean, safe, and reliable work for every project. Contact us to discuss your job.
Get in touch
BRI BASE Ltd
No reviews yet
Extension Builder in Belsize
I'm Ahsan Chohan, from BRAND BOA construction, a UK-based construction estimation and building services company specializing in precision estimating worldwide. We provide expert construction quantity takeoffs, cost estimates, and comprehensive building services including building extensions, new builds, interior finishing, refurbishment, MEP (Mechanical, Electrical, Plumbing), masonry, and general construction work. What sets us apart is our commitment to precision estimating and deep understanding of the UK construction market. Whether you're planning extensions, new builds, refurbishments, or specialized construction projects, we deliver reliable solutions that prevent costly overruns and delays. Our team combines technical expertise with practical industry knowledge, ensuring every project meets the highest standards of safety, quality, and accuracy. We focus on building long-term partnerships with clients who value expertise, reliability, and results.
Get in touch
S fartade serban
No reviews yet
Extension Builder in Belsize
Hello, and thank you for considering our services for your construction needs. We are a team of experienced professionals dedicated to delivering high-quality, reliable, and innovative construction solutions. Whether you're planning a residential project, a commercial build, or a renovation, we bring expertise, attention to detail, and a commitment to customer satisfaction to every job we take on. Our goal is to make your vision a reality, from the initial design phase through to project completion. We prioritize clear communication, timely execution, and ensuring your project stays on budget. With us, you can expect a seamless experience and outstanding results.
Get in touch
S&r building ltd
No reviews yet
Extension Builder in Belsize
New build Extension Loft conversion Full refurbishment
Get in touch
CTU Interiors Ltd
Rating: 5 out of 5
Extension Builder in Belsize
I have over 15 years experience working on the tools. I started building work with my Dad when I was still in school and joined him professionally when I was 19, I am now 37. I started on suspended ceilings and plaster boarding walls and ceilings. Then I moved into more residential works doing extensions and refurbishments. I have a good team of guys around me that between us we can get any job done for you. Customer satisfaction is very important because you are as good as your last job!
Get in touch
Latest review:
Plastering- 9 May 2016
Managed to fit me in at short notice and the plasterer did a thoroughly professional job and was pleasant with it.
True North Solutions
No reviews yet
Extension Builder in Belsize
True North Solutions is a family-owned business with years of experience in home improvement and repairs. We specialise in bricklaying, offering high-quality work for everything from walls and patios to custom brick structures. At True North Solutions, we focus on providing reliable, long-lasting solutions tailored to each client’s needs. With a strong commitment to quality and attention to detail, we make sure every project is completed to the highest standard, adding lasting value to your home.
Get in touch
G G Property Development Limited
Rating: 5 out of 5
Extension Builder in Belsize
We are a friendly hard working company. We pride ourselves on archiving high standards of works in short time periods. We have carried various works from new builds, complete property refurbishments, extension, loft conversion, kitchens, bathrooms, electrical and plumbing works, plastering, rendering. All works are guaranteed and fully insurance. We are a commercial, industrial and domestic company. We have many photos of works and website shall be finished in the near future.
Get in touch
Latest review:
Loft Conversion- 5 Dec 2018
Firstly the date of job posting and date of completing is all down to me not being ready with finances!! Secondly, and more importantly, GG Property were the most wonderful and professional bunch of lads you can hope to met. The work was done with such enthusiasm and to such a high level of detail. We could not be happier with the finished job. Thirdly, the great building work aside, GG Property were polite, happy, friendly, punctual and great communicators. All emails answered swiftly and with accurate information. No question was to silly and no concern (this was our first major building working) was to small to be addressed. Finally we are so pleased with work we are awaiting a quote for our bathroom and look forward to getting that job completed!! In short my experience with GG Property was nothing but top quality work and customer service. Any fears of the classic 'cowboy builder' could not be further from the truth; GG Property are a hard working truly lovely bunch and we would highly recommend them.
FlynnAndSon Ltd
Rating: 5 out of 5
Extension Builder in Belsize
Hi, We are new to MyBuilder and our friendly team has over 30+ years expert experience. We would be grateful for the opportunity to provide you with the most cost effective quote for the very best quality workmanship. No job is too big or too small. All work is guaranteed and we are both Trustmark & Federation of Master Builder members. I hope to meet you soon.
Get in touch
Latest review:
Bricklaying- 9 Jul 2020
Kevin has been really helpful in explaining what needed to be done and did the job in a timely manner. He walked me around the property before starting the job and after to inspect the work that had been carried out. I would definitely recommend him for any future works.
The Mangrove Group
Rating: 5 out of 5
Extension Builder in Belsize
We do a vast amount of work from extensions and loft conversions to fences and garden walls. We’re a family run business that will work with our clients to ensure they get what is aesthetically pleasing and long lasting.
Get in touch
Latest review:
7 months ago loft alteration. All work to the roof and brickwork completed efficiently and in excellent time. windows, doors, and flooring fitted perfectly Very pleasant polite and professional Builders. would genuinely recommend .
Woodford Construction Services Ltd
No reviews yet
Extension Builder in Belsize
Woodford Construction Services Ltd (WCSL) is a building, construction, and refurbishment company, which has been established for more than 25 years. As reputable building contractor, WCSL is able to offer a wealth of experience, having undertaken a broad spectrum of projects in the past. From small residential refurbishments, to large scale, high-value commercial developments, we are confident that we can provide the skills and services that your building project will require. WCSL offer a range of construction services, from architecture and interior design, to building and refurbishment. We have established and developed a diverse variety of expertise, which can be evidenced through our extensive portfolio of previous commissions. From minor alterations, to larger home builds, we have previously taken on a variety of internal and external residential projects. These have included extensions, loft conversions, and various internal refurbishments, including interior fit outs. We have also been involved in a wide range of commercial construction projects. This has ranged from new build construction, to the extensive refurbishment of flats, houses, offices and industrial units.
Get in touch
MH Styles. Ltd Ltd
No reviews yet
Extension Builder in Belsize
Very good job
Get in touch
Cera Building Renovation
No reviews yet
Extension Builder in Belsize
Our experience allows us to be efficient and effective.We specialise in Extension, Loft Conversion, Renovation, Electric, Plumbing, Kitchens, Bathrooms, Plastering and Rendering, Painting and Decorating, and this allows us to transform any part of your home into the vision you have for it and this is what gives us the passion for what we do! You can find us on Google Instagram or Facebook.
Get in touch
Constantin Birgauan
No reviews yet
Extension Builder in Belsize
BRICKWORK, BLOCKWORK AND EXTENSIONS. Please feel free to contact me anytime for quotes and questions.
Get in touch
Annabaffer pierre
No reviews yet
Extension Builder in Belsize
I am a head working individual no jobs to big or to small to handle from St Lucia love to play football
Get in touch
Newstar Building Services Ltd
Rating: 4.9 out of 5
Extension Builder in Belsize
HI my name is Bill and I run a building company. All our work is base on recommendations costumers We work all around London.
Get in touch
Latest review:
Hard Flooring- 22 Oct 2025
Enea did an incredible job, and we’re beyond happy with the final result. He was very accommodating, helped us choose the right tone of varnish beforehand, and kept us updated throughout the day by sending pictures of his progress (as we were both at work). Enea is trustworthy, and even though we didn’t have the chance to meet him in person, he left the flat securely, taking care of our keys and door. We highly recommend Enea!

Top rated Extension Builders

Our Extension Builders in Belsize, are rated 4 out of 5 based on 17 reviews from customers like you.

Quality screening

Easily find verified local tradespeople. Just post your job to get quotes from tradespeople near you across the UK.

What types of services are offered by local extension builders in Belsize?

Building an extension is a major milestone for any home. It’s not just about adding extra space, it’s a big step that can transform how you live day to day, opening up new possibilities for comfort, lifestyle, and family needs.

This is why it’s so important to find the right extension builders in Belsize for you. They can help with a variety of tasks and projects, including:

Extending your home with an extra room
Two+ storey extensions
Adding partition walls to create more rooms
Building annexes or external structures

To find the right extension builder near you, simply post your job on MyBuilder. Explain the type of help you’re looking for, and then home extension builders in Belsize who are available and interested can respond to your post.

Browse profiles, read customer reviews and get quotes from your chosen Belsize extension builders, all before you decide who to hire.

What are the hourly rates of extension builders in Belsize?

Before getting started with your extension project, it’s important to have a clear budget in place. On average, extension builders in Belsize will charge between £16 and £42 per hour.

Single-storey rear extensions cost between £20,000 and £60,000 depending on size and finish.
The cost of double-storey extensions, which add more space and value, can range from £100,000 to over £170,000.
Larger wrap-around extensions that combine multiple extension types can range from £40,000 to over £120,000.

The cost of an extension will vary depending on your property. For instance, extending in certain areas may require structural adjustments to ensure stability, which can increase your material and labour costs.

To get an accurate price for your home extension, request detailed quotes from several Belsize extension builders near you on MyBuilder. This allows you to compare what each quote covers and how much your Belsize home extension project is likely to cost.

Find extension builders in Belsize with MyBuilder

Hiring the right extension builder in Belsize with MyBuilder couldn’t be easier. Just follow these simple steps:

Step 1: Post your extension project on MyBuilder

Whether you’re planning a single-storey extension, a loft conversion, or adding a new room, post your job on MyBuilder to find local Belsize extension builders. Once your job is live, we’ll share it with home extension builders in Belsize who can express their interest.

Step 2: Compare different extension builders in Belsize

When you start receiving interest, review profiles of local Belsize extension builders, check their previous work, and read real customer reviews. Ask about timelines, materials, and request detailed quotes.

Step 3: Hire Belsize extension builders with confidence

After gathering all the information and quotes from your chosen home extension builders in Belsize, compare their experience, guarantees, and costs before choosing who to hire.

You’ll also have confidence knowing that every tradesperson on MyBuilder is verified through several checks, including:

ID verification: When a tradesperson joins MyBuilder, we ask for a valid ID, such as a passport, ID card, or eIDAS certificate.
Company verification: For tradespeople operating under a company, we make sure every tradesperson has a registered business.

Did you know? Our continuous monitoring and complaints process ensures that tradespeople who don’t meet our standards are promptly removed from MyBuilder’s platform.

Belsize extension builders are ready to help. Use MyBuilder today to find the right professional for your home extension.

What to ask a Belsize extension builder before hiring?

Before hiring an extension builder in Belsize or extension building company in Belsize, ask a few key questions to make sure you’re choosing the right professional for your home extension project.

What qualifications and experience do you have as an extension builder in Belsize?

An extension builder in Belsize should have a strong track record with similar projects and relevant building qualifications or trade memberships, such as the Federation of Master Builders (FMB) or TrustMark.

Will my home extension meet all building regulations and planning requirements?

Your Belsize extension builder should ensure the project complies with Building Regulations and, where necessary, handle or assist with planning permissions. Ask how they manage building control inspections and what documentation you’ll receive once the project is complete.

What experience do you have with similar extensions in Belsize?

Ask to see examples of their previous work, or view examples of their work on MyBuilder. Ideally projects similar to yours in scale and design. This helps you assess the Belsize extension builder’s ability to deliver a result that meets your expectations.

How long will the extension take to complete?

Extension project timelines can vary depending on size, complexity, and weather. A typical single-storey extension might take around 8 - 12 weeks. Request a detailed schedule so you know what to expect and when key milestones will be reached.

Do you offer a guarantee for your work? Most Belsize extension builders offer a guarantee or warranty on their work, often between 1 and 10 years depending on the project and materials used. This gives you assurance that any issues will be resolved after completion.

If you still have questions about the professional you are looking to hire, we have a full detailed guide on hiring the right builder here.

FAQ: Common questions about home extensions in Belsize

Can an extension builder in Belsize help with planning permission?

Yes, many extension builders in Belsize can guide you through the planning process. They can help prepare drawings, advise on local requirements, and liaise with your local council to ensure your project meets all necessary regulations.

Can an extension builder in Belsize handle everything from design to construction?

Many Belsize extension builders offer full design-and-build services, managing both the architectural planning and construction stages. Ask your builder whether they can provide a complete package or if you’ll need to hire an architect or designer separately.

Will an extension builder in Belsize help with materials and finishes?

Yes, most extension builders in Belsize can source materials and offer advice on finishes that suit your design and budget. You can also choose to supply certain materials yourself, just make sure this is agreed upon before work starts.