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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MT Building Services
Rating: 4.9 out of 5
Extension Builder in St James
MT Building Services here, we undertake all Building construction work from beginning to end. We are specialised in loft conversions, extension, full house refurbishments. We undertake small jobs aswell as flooring, kitchens,doors etc etc. Contact us for quotations. Thanks MT BUILDING SERVICES
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Latest review:
Restoration & Refurbishment- 2 Aug 2025
Asen did an incredible job! In just under 4 weeks he managed to assemble a team and complete renovation on a 2 bed flat including: * Full rewiring, new lights, updating and adding sockets * Fixing rotten and uneven subfloor and levelling the whole house * Wood flooring throughout - done excellently with no thresholds * New boiler and all new radiators * Built a pocket door at the porch to stop our kitties from escaping * Tiled the fireplace * Skirting, decorating and repainting the entire flat * Dealt with gutting the place and arranging pickup of rubish The place looks and feels amazing and everything works! Asen was good on the price, kept to the (very tight) timelines, great communication throughout and overall very professional and friendly! Pics shows after and during the work, ignore the moving boxes.
Remas Construction
Rating: 5 out of 5
Extension Builder in St James
I been in construction field for over 16 years: (Electric, Plumbing, Plasterboard, Painting, Flooring, Carpentry, GlassWork, Kitchen & Bathroom, Extension and much more..) I believe that quality is the result of careful planning and execution. Daily maintenance solutions.. (Urgent & Same day Service). Best price in London, Guarantee 💯 GENERAL CONTRACTOR'S Commercial & Residential Home inspection
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Latest review:
Ahmad did an exceptionally good job. He painted a large number of walls, filled them, gave me a recommendation as to what paint should be used and left everything clean and tidy every day. Highly recommended.
Mos Structure Ltd.
Rating: 5 out of 5
Extension Builder in St James
We are construction company based in London. The director of the Mos Structure Ltd. completed his education at the faculty of engineering in Turkey. After his education and his carier he started his own business in London. Totally he has been in this industry more than 14 years. We are a understanding and friendly team who always have a smile on our face. We have 100% customer satisfaction and have worked from great recommendations.
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Latest review:
We needed a rear extension built with an internal courtyard. From day one when we first contacted Mert to get a quote he was professional and easy to talk to. His quote was good value for money. During the job he and his team were approachable, careful with our property and always easy to talk to and answer questions we had. The work Mert did was fantastic and our neighbours have already gone on to use him. We will get him back again for more work and highly recommend him.
ADJ Builders Limited
Rating: 5 out of 5
Extension Builder in St James
Hello ..my name is Alfred. I, have over 12 years of experience in building site. Perfectionist in my work and ability to guarantee customer satisfaction. Hard working and ensures all deadlines and targets are met. A good eye for detail, precise and accurate at all times and will complete all work to the highest standards.My experience shows in the finish, with no visible streaks. Polite friendly and helpful.
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Latest review:
Painting & Decorating- 6 Oct 2022
Very pleased with our choice. We initially got four quotes from different builders, most of them were terrible at communicating apart from Alfred. He was very easy to work with, responsive and very careful with our brand new house. His team was hard working, tidy and fast. They completely renovated our garden from removal of old decking and gravel to setting up new fences, levelling and turfing the ground. They also removed our old kitchen, partition wall and carpet, as well as did jobs like plastering, building a wall and set up lights and shelves. We’ll surely have him back soon to work on other jobs.
Artizan landscapers ltd
Rating: 4.9 out of 5
Extension Builder in St James
I have been doing garderning for over 20 years i have 8 certificates in gardening i have done domestic gardens and comerecial gardens
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Latest review:
Garden Maintenance- 2 May 2026
A++
Omar Construction LTd
Rating: 5 out of 5
Extension Builder in St James
Omar Construction is a family-owned limited company situated in London that has been around for several years undertaking all kinds of construction work such as loft conversions, extensions & refurbishments. We have one simple policy; Make the Customer Happy. For several years we have managed to uphold this very simple policy. With over 21 years of industry experience and an elite team of reputable tradesmen, let us be your first choice, to make your dream project a reality.
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Latest review:
Extensions- 16 Oct 2022
Amazing people ,glad I went with them to do the extension ,they did a really wonderful job .Now we have a builder and a friend to rely on .Thank you very much Mustafa,Omar,Imran and Hamid ,you guys are awesome 👍
London Builders & Decorators
Rating: 5 out of 5
Extension Builder in St James
London Builders & Decorators has been operating since 2016 in London. We our general builders who carry out Extensions, Lofts and Full Renovations. Why not shortlist us and come visit one of our sites. We run 5-7 sites at once so there will be one nearby. We try to keep things simple so the customer knows what is being done. Building work should be explained and expectations should be managed. We are a Member of the Federation of Master Builders & Gas Safe Registered
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Latest review:
Tiling- 22 Mar 2018
very professional work, the team was very flexible, patient and helpful with me adding some ideas along the way. I am very happy with the results.
Cunningham Developments & Property services ltd
Rating: 4.8 out of 5
Extension Builder in St James
Cunningham Developments and Property Services Ltd is an innovative, family-run design, planning, and construction company with over 16 years of experience in architecture planning and construction. We specialize in providing comprehensive services that encompass every stage of the development process, from initial design concepts to project completion. At Cunningham Developments, we pride ourselves on our commitment and the willingness to achieve clientele satisfaction.
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Latest review:
CAD / Drawings- 11 Sep 2025
Justin was responsive and reliable in nudging the council. Got a greater scope approved, too
Adam Favor
Rating: 4.8 out of 5
Extension Builder in St James
Our business was founded to offer clients the opportunity to bring a vision to life. As a design & build business we can take your dream home concept and turn it into reality. We will provide you with design plans for your projects and thorough project management. We also have the professional, experienced and quality tradesmen that are essential to complete the construction phase of the project.
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Latest review:
Plastering- 17 Jun 2024
Adam Favor and NOVA Design & Build are a nice bunch of guys and they are reliable/helpful. However, when it came to coving, architrave and flooring, acceptable standards were unfortunately not met. Other specialists had to be brought in to re-do around 20% of the job; namely certain sections of the cornice and door architrave. In the former, a few things were below standard including: 1) not joining the friezes in the correct places, 2) cutting inaccurately, 3) leaving gaps, 4) using silicon as a filler and adhesive. For the door architrave, the wood was misaligned and not glued/nailed properly. The flooring was not laid well because there are huge gaps at times; sometimes at 1 cm. Since the kitchen has been installed, it is too late to take up the floorboards again. The most dubious thing of all in this job was the quote received for decorating which was c. 15k for 47 m2. This included plastering repairs, but ultimately the job got done by someone else to a high standard at 7k.
Livinroom Developers Ltd
Rating: 5 out of 5
Extension Builder in St James
Our expertise lies in project management of loft conversion and kitchen extension which is carefully coordinated to ensure a seamless and integrated package service from start to finish. Our role is to be the single point of responsibility taking the burden off the client. This includes managing what are often complex building processes from inception through to completion and hand over.
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Latest review:
I recently completed the building of an orangery extension (with skylight) to my semi-detached townhouse in NW London. The extension was to be used as a new kitchen while the existing kitchen converted to a living room. I awarded the contract of building the extension to Anthony and I was pleasantly impressed with the quality of work delivered. Anthony Project Managed the entire process from beginning to end and ensured that all my expectations were surpassed. His hands-on attitude to every detail of the work was quite reassuring. I am glad to say that Anthony and his team are very good professionals and they delivered the project on time and within budget, even going over and beyond the original scope of works in order to ensure that all my latter requests were addressed appropriately.
CRAFTSMAN CONSTRUCTION LTD
Rating: 5 out of 5
Extension Builder in St James
Welcome, and thank you for choosing us for your construction needs. We want you to feel completely comfortable and at ease when speaking with us. No question is too small or too big — we are here to listen, guide you, and support you at every step of your project. Our goal is to create a peaceful, respectful, and open environment where you can freely share your ideas, concerns, and expectations. We look forward to working with you and turning your vision into reality. Please feel free to reach out anytime. We are always happy to help.
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Latest review:
Extensions- 3 Feb 2026
The job went perfectly. The Builders arrived on time and finished all the work in two days the work was completed to a perfect standard he even cleaned up some of the mess that previous Builders had left behind, their work. I can say without hesitation is exemplary. I would highly recommend hiring Craftsman Construction Limited
UCSCONSTRUCTION & DAMPROOFING SERVICES
Rating: 5 out of 5
Extension Builder in St James
My work involves all aspects of construction, renovations, internal & external works & structural alterations. I have been in this industry for 25yrs+. Working along side me I have both architects & structural engineers which allows UCS CONSTRUCTION to offer a complete package within the team, We operate in most parts of the london areas. As the team head & owner of UCS we are fully qualified to offer all necessary gas/elec certification & operate with a £5m liability insurance cover.
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Latest review:
Kitchen Fitting- 31 May 2021
We were thrilled with the service from UCS Construction. Richard was efficient, considerate and professional throughout the planning and the execution of this job. He consulted us so we agreed on exactly what we wanted and went over and above to ensure it all went smoothly. We can’t recommend him highly enough...we are so pleased. Thank you Richard.
Balham construction Ltd
Rating: 5 out of 5
Extension Builder in St James
Balham construction are a London based refurbishment and construction company that offer a wide range of services from full Property refurbishment to extensions and loft conversions and everything in between
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Latest review:
Tom and the team completed a full renovation of my flat. This included refurbishment of my kitchen, bathroom and general redecoration. The team were extremely hardworking and punctual and no job was too difficult for them. I would highly recommend their services.
adam lloyd construction ltd
Rating: 5 out of 5
Extension Builder in St James
At Adam Lloyd construction we specialise in high end refurbishments but we also undertake small works and maintenance from decorating to landscaping we have excellent tradesmen in-house
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Latest review:
This carpenter is a plywood maestro! My wardrobes are a testament to their craftsmanship – sturdy, stylish, and a definite upgrade from my previous cardboard chaos. Would highly recommend for a wardrobe transformation that's as solid as it is delightful. ⚒️👌 Top notch, class A stuff 👍🏻
WOODHOUSE BUILDERS LIMITED
Rating: 4.8 out of 5
Extension Builder in St James
Welcome to Woodhouse Builders Ltd, we cover all aspects of property maintenance and no job is too small or big for us. If it’s a small decorating job or full property renovation , loft conversion or extension , we are here to help and provide the best services possible . Our success is built on providing the best services and ensuring that all our customers are happy with our services.
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Latest review:
Extensions- 6 Apr 2020
Art & team did a brilliant job in building my rear extension and renovating the whole apartment. Communication was excellent throughout and the job was completed on time and to the agreed budget. The finish throughout was to a high standard. I would definitely work with these guys again and highly recommend. Regards MZ
DC Brickwork
Rating: 5 out of 5
Extension Builder in St James
Dear Customers I am honest trustworthy reliable and hardworking and I have over 25 years experience in the industry.
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Latest review:
Bricklaying- 29 Jun 2017
I would recommend Damian. Did a good job, good communication and was on site when he said he would be. Polite and friendly. I would be happy to use again.

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.