Extension Builders in St James

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4.4 (19 reviews)

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Some of our top rated extension builders in St James

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Rating: 5 out of 5
Extension Builder in St James
Skilled, tidy bricklayer. Highly competent in building, pointing and restoration. Garden walls, extensions, new builds, etc
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Latest review:
Jack built a brick buttress to structurally support my garden wall. Originally I was going to rebuild the entire wall, but Jack’s advice to build a buttress saved me a lot of money! The job was done quickly, affordably and to a high standard. Would highly recommend.
Alpha Construction & Development Group Ltd
Rating: 5 out of 5
Extension Builder in St James
Alpha Construction & Development Group Ltd offer bespoke service with a focus on the needs of our customers. We deliver one project at a time, without delays and stress-free. From small to big projects, we strive for the highest quality of work. We specialise in but are not limited to new builds, extensions, lofts conversions, structural works, roofing, plastering, rendering, painting and decorating, renovations, kitchen and bathroom fittings, pavings, brickwork, plumbing, full refurbishments.
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Latest review:
Bathroom Fitting- 25 Feb 2022
This was the best experience I have ever had with a team of builders. Aldo and Leo were polite, organised and their workmanship is of a very high standard. They replaced the bathroom in our rental flat, and it looks really smart. They also refurbished the kitchen, replacing flooring and decorated the whole flat. We have just shown it to an estate agent as we are planning to sell it and they were very impressed. Aldo was very helpful in making suggestions of small changes that would save us money and delivered the project on time and right on budget. Would recommend them and will certainly use them again.
YOB CONSTRUCTION LTD
Rating: 5 out of 5
Extension Builder in St James
At YOB Construction Ltd, we believe your home or business deserves the highest standard of workmanship. Based in North West London and proudly serving the surrounding areas, we specialise in a full range of building and renovation services, from kitchen and bathroom installations to bespoke carpentry, tiling, painting, decorating, and complete refurbishments and extensions. What sets us apart is our commitment to quality, reliability, and customer care. Every project, no matter the size, is managed with precision and attention to detail. We work closely with our clients to understand their vision, provide honest advice, and deliver results that not only meet expectations but exceed them. With years of experience and a team of skilled professionals, YOB Construction Ltd has built a reputation for trust, professionalism, and lasting results. We source only high-quality materials, maintain clear communication throughout the process, and ensure every job is completed on time and to the highest standard. Whether you’re refreshing a single room or transforming an entire property, you can rely on us to bring your ideas to life with skill, care, and dedication. Get in touch today for a free, no-obligation quote.
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Latest review:
Bathroom Fitting- 9 Nov 2025
Very good work. Alaa repared the tap in my bathroom and fixed a broken tile. The end result is excellent. I highly recommend.
Dimitrios Spanos
Rating: 3.7 out of 5
Extension Builder in St James
KDG Building & Consulting Services is specialist in all aspects of general building and property maintenance, extensions, loft conversions, structural waterproofing and painting and decorating related works for both private and commercial Clients in Central and Greater London. We take pride in our bespoke building services and make sure every project is nothing less than what our Clients will expect, driven by our values to deliver long lasting and high standards results.
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Latest review:
Tiling- 28 May 2020
Did not arrive to complete the job or have the professionalism to cancel in advance. Unreliable company.
Mile Kresojevic
Rating: 5 out of 5
Extension Builder in St James
Hi, I am experienced self-employed carpenter with 10 years in various projects, working directly for clients while entrusted for their property. Good English, punctual, trustworthy and a reliable time keeper. Can provide references on request.
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Latest review:
Carpentry- 5 Dec 2017
Mile was prompt in supplying a quote and fitted us in within days. He was tidy in his work, pleasant to deal with and reasonable with his quote, we will use him again should we need any carpentry work.
Property DMR Services Ltd
Rating: 5 out of 5
Extension Builder in St James
Property DMR Services Ltd is a high end building company that specialises in refurbishing high end properties in and around London. All our work is insured & guaranteed. We undertake Basement Construction & Waterproofing, Extensions, Loft Conversions & Renovation, Decorating and wallpapering plus Bespoke Joinery & Shop Fitting
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Latest review:
Restoration & Refurbishment- 12 Sep 2024
From the first impression, throughout the early stage discussions and right up to the end - Matthew was consistently punctual, fair, thorough and reliable. Excellent execution of jobs and flat was left tidier than before. Would not hesitate in hiring him again or recommending.
Trend House Design limited
Rating: 5 out of 5
Extension Builder in St James
Trend House Design limited offer independent carpentry and joinery 1&2, fix with certification NVQ LEVEL 3 specialise on refurbishments and high end floors over 9 years experience. We are proud to offer our advice reliable and friendly service within the South West London area.
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Latest review:
Joinery & Cabinet Making- 26 Jun 2024
Absolutely great service. The media was built exactly how we wanted. Nicolae would use his expertise to guide us and improve our design where appropriate. The end result was a unique and difficult to make arch media wall with integrated electrics and lighting
Arethusa Restoration
Rating: 5 out of 5
Extension Builder in St James
"ARL-Contractors" Arethusa Restoration Limited Is an Italian company offering an unrivalled quality of service as both Principal contractor in the refurbishment and renovation of houses, extensions, loft conversion and, commercial restoration and fit-out & Specialist contractors in the restoration of period and historic buildings, offering a niche service spanning traditional façade cleaning, restoration, conversion into new luxury modernised living spaces.
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Latest review:
Plastering- 19 Dec 2018
Roberto came out to site and quoted, I felt very confident and reassured by him very quickly. He quoted for the whole work and arrived and left on time. There was a lot of attention to detail on this job I am happy with his work, he is highly skilled, works hard and is also nice to be around. I will hire him again, if I need his speciality services in the near future.
KEVIN CONSTRUCTION SOLUTIONS LIMITED
Rating: 5 out of 5
Extension Builder in St James
Kevin Construction is a London-based, well-organised construction company specialising in large-scale developments alongside leading UK firms. We offer a full suite of services—from extensions and conversions to structural alterations and landscaping. With a dedicated team, digital management tools, and a focus on quality, we guide every project from planning to successful completion.
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Latest review:
Fencing- 13 May 2026
Kevin turned up on time and did a solid job on my fence. Would use again
JM Building Service
Rating: 4.7 out of 5
Extension Builder in St James
Hi my name is Joe from JM Building Service and I would like the opportunity to come and have a look at any works you require my services for. I look forward to meeting you. Thank you.
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Latest review:
Bathroom Fitting- 14 Mar 2025
My previous bathroom fitters did a very bad job with the bathroom and cloakroom toilet and left it unfinished. I am so glad I went with JM Building service as Joe and Martin completely transformed both rooms. They rectified the previous fitters errors and completed the rooms. Joe didn’t just rush through the job to get it done quickly—he took his time, ensuring every detail was finished to a high standard. He worked meticulously, making adjustments until everything looked exactly as it should, rather than settling for ‘good enough.’ His dedication to quality and precision was evident throughout, and the end result speaks for itself. As well as being very good at what they do, they are friendly, reliable, trustworthy and hardworking. I have already booked them in for another job and requested a quote for another. I highly recommend JM Building services for their professionalism and craftsmanship.
Robert Krysta
Rating: 5 out of 5
Extension Builder in St James
I started trading in 2004 as bathroom and kitchen fitter. Since then I've done many projects, those large and really small. All jobs were finished with great attention to details, satisfaction and great appreciation of all my clients.
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Latest review:
Bathroom Fitting- 1 Nov 2024
Absolute expert at his craft and pleasure to work with. Thank you 👍
Basibel Building Services
Rating: 5 out of 5
Extension Builder in St James
Our business has been established for over 30 years, mostly covering bathroom and kitchen fittings, complete refurbishments, extensions to plumbing and carpentry services. Proud to say that in all these years we have not had a single bad review, bold claim but true! Feel free to get in touch for a no obligation chat, we may be a solution to your problems, look forward to hearing from you! Best, Nesha
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Latest review:
Kitchen Fitting- 29 May 2024
Nesha was brilliant from start to finish. He was excellent at communicating before the job and was entirely professional and hard working throughout, not to mention his quote was very reasonable. He worked really hard to get the job done quickly and he did it to a fantastic standard. We are so pleased with the finished product and he was a pleasure to work with. We cannot recommend Nesha highly enough.
edildue
Rating: 5 out of 5
Extension Builder in St James
Groundworks, Fromwork, steel fixing, casting , general builders, carpentery , tiles , concrete , wood floor
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Latest review:
Handyman- 6 Nov 2023
Michele and his team did an excellent job of improving the external area of our property. Very professional communication, job was done to a high standard at a fair price. Done in a very timely manner and would highly recommend.
Til construction LTD
Rating: 5 out of 5
Extension Builder in St James
TIL Construction LTD is a well-establish company that provides a complete and cost-effective solution for your building needs. We pride ourselves on a team of highly skilled craftsmen and professionals ready to deliver any sized construction project from start to finish. Whether it’s a new build, extension, loft conversion, or renovation, we can help with a portfolio of building work across London and other cities within the UK.
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Latest review:
Carpentry- 5 Aug 2023
A gréât expérience. Thé team were very professional, well priced, and did a great job. They left our apartment immaculately clean and fixed all issues we had. They were extremely polite and responsive and did a great job in the timeframe and for the quoted cost. Highly recommend
Ed’s loft conversions Ltd
Rating: 5 out of 5
Extension Builder in St James
We specialise in loft conversions, Extension to a complete house refurbishment.
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Latest review:
I engaged Edi to work on a full renovation and refurbishment of a 4 bedroom detached house with front and back gardens on Blackheath’s Cator Estate. Edi did an extensive amount of work, including stripping out; plumbing; plastering; windows installation; carpentry; and decoration. In addition, after commencing the property work, once the scaffold had been erected, following sensible advice, Edi and his team replaced the roof and fully insulated the attic; fitted additional electric points; rebuilt the garden patio; and replaced the flooring throughout, in addition to other important jobs including re rendering and pointing of chimneys, building new wardrobes in the main bedrooms; and upgrading the radiators. A new kitchen, and two new bathrooms have been fitted. The kitchen redesign meant knocking through a wall with the lounge to create a larger space. Edi is a highly skilled craftsman, who thinks creatively as he works to make best use of the space, including shelf fittings, and additional lighting for example. He has built some beautiful wardrobes, and the internal decorations have brightened up what was previously a rather shabby looking house. In addition to the above, I wish to commend Edi for his professionalism, courtesy, and passion for doing the best work possible. On all the site visits I attended, and every time I spoke with him on the phone, it was striking how much he cared about the work that he was doing, his desire to ensure that the house would look the best. I always left site visits with the feeling that he cared so much about the house that he could be safely relied on to give the best advice to enable us to make the right decisions. I also noticed that Edi and his team would take the upmost care to keep the property safe, tidy and in good shape throughout the project. He can be fully trusted to look after any site he works on. He is intelligent and careful when it comes to safety and security. It has been a pleasure for Edi and his team to work with us over a period of around 6 months, and he did so much to reduce the stress of a significant project so that we could always rely on him to work methodically, patiently and sensibly, and to make best use of the resources available. His pleasantness shines through, and everyone I know who has spoken to him has always provided me with the most positive feedback I have no hesitation in recommending Edi to anyone who wishes to engage him for future projects, and is most deserving of the good words that I and others that work with him have to say about him.
CCM CAPITAL CONSTRUCTION LIMITED
Rating: 4.8 out of 5
Extension Builder in St James
All construction work
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Latest review:
Bathroom Fitting- 30 Nov 2025
Mohsen and his team are very professional workers. They communicated clearly with me during the quoting process and were very helpful. They replaced my shower tray and shower screen beautifully and exceeded my expectations. Highly recommend their work!

4.4

Top rated Extension Builders

Our Extension Builders in St James, are rated 4.4 out of 5 based on 19 reviews from customers like you.

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

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 St James 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 St James who are available and interested can respond to your post.

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

What are the hourly rates of extension builders in St James?

Before getting started with your extension project, it’s important to have a clear budget in place. On average, extension builders in St James 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 St James extension builders near you on MyBuilder. This allows you to compare what each quote covers and how much your St James home extension project is likely to cost.

Find extension builders in St James with MyBuilder

Hiring the right extension builder in St James 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 St James extension builders. Once your job is live, we’ll share it with home extension builders in St James who can express their interest.

Step 2: Compare different extension builders in St James

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

Step 3: Hire St James extension builders with confidence

After gathering all the information and quotes from your chosen home extension builders in St James, 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.

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

What to ask a St James extension builder before hiring?

Before hiring an extension builder in St James or extension building company in St James, 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 St James?

An extension builder in St James 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 St James 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 St James?

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 St James 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 St James 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 St James

Can an extension builder in St James help with planning permission?

Yes, many extension builders in St James 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 St James handle everything from design to construction?

Many St James 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 St James help with materials and finishes?

Yes, most extension builders in St James 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.