Extension Builders in St James

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4.2 (19 reviews)

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Some of our top rated extension builders in St James

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GRB Building and Home Improvements
Rating: 5 out of 5
Extension Builder in St James
At GRB Home Improvements we have over 15 Years experience in general building contracting including extensions, kitchen and bathroom refits, loft conversions, garden landscaping, patios and outbuildings, drainage and groundwork, drives and general building maintenance. We passionately believe in customer satisfaction and strive to ensure that our quality work is delivered on time, as per the agreed schedule, and that we come in on budget.
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Latest review:
Carpentry- 24 Jan 2021
George came to do up our hallway. He laid flooring and installed new spindles and a handrail on our stairs too. He did a wonderful job on the whole lot and we were very happy with him. We were awkward and changed our mind on the first laminate flooring that I had picked out online, he ripped it up and started again with the new flooring we picked and it was no hassle to him. George is a lovely fella, trustworthy and professional. Would highly recommend
MAF Contacts
Rating: 5 out of 5
Extension Builder in St James
Hello, My name is Dan Maftei, Founder of MAF Contracts ltd. MAF offers a range of services like demolition( stripping out), Plumbing, Electric, Rendering and Plastering, Painting and decorating, Tiling, Flooring, Carpentry first fix and second fix, Paving, Roofing, extension and Loft conversion. We can deal with big projects as well as small ones. Thank you, Dan Maftei
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Latest review:
Restoration & Refurbishment- 29 Dec 2018
Amazing work. A job very well done. Very hardworking people and high quality work. All was delivered exactly as agreed in time and to perfection. Thank you again for transforming my flat in such a lovely space.
Rizart terzeta
Rating: 5 out of 5
Extension Builder in St James
Experienced London-based carpenter specialising in commercial and residential work. Certified fire door installer, delivering high-quality, reliable, and compliant workmanship. Tape and joint Painting Glazing Partition walls Wall panels Standard doors Fire doors
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Latest review:
Carpentry- 10 Nov 2025
We know how difficult is to find someone reliable who knows what is doing. Well ,Rizart is the one who you can trust, relay on and have the job done in no time. 8 fire doors fitted in 2 days with certificates Thank you Rizart
D.L.CONS LTD
Rating: 5 out of 5
Extension Builder in St James
Hi, I’m Dan, the owner of D.L.CONS LTD – a small, skilled, and reliable building company based in E9, London. With 25+ years of experience, I’ve pretty much done it all – and done it well. I specialize in bathroom and kitchen fitting, bricklaying, painting & decorating, and carpentry, and over the years, I’ve worked on everything from domestic extensions to shop renovations. Whether it's transforming a small bathroom or building an entire extension, my team and I focus on quality, precision, and attention to detail—because great craftsmanship speaks for itself. We mainly work in E9 and the surrounding high-end postcodes—Hackney, Victoria Park, London Fields,and Islington. If you're looking for top-quality workmanship with no shortcuts, I’d love to hear about your project. Let’s build something great together.
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Latest review:
Carpentry- 8 Apr 2026
I’m really happy with the work carried out. He came in to fix my steps after a previous builder had damaged them and left them unstable, and the difference is night and day. Everything now feels solid, secure and properly finished. He also fixed the skirting boards and installed my desk, all to a very high standard. What I really appreciated was how professional he was throughout and the advice he gave along the way, which showed real experience and care for the job. Overall, a really high-quality finish and a great attitude. I wouldn’t hesitate to recommend him.
Perfectloft
Rating: 5 out of 5
Extension Builder in St James
Converting your loft into a beautiful living space may seem like a daunting task, but the results are always going to be worth the painstaking process. The loft conversion procedure does not have to be that difficult; all you require is to hire right people to do the right job.
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Latest review:
Kitchen Fitting- 4 Nov 2019
Bogdan and Marius were great. They constantly kept us updated with progress and came up with good solutions to any issues they encountered, checking we were OK with them before progressing. They were on time, efficient, helpful and tidied up after themselves. I would definitely recommend them.
Sadia
Rating: 5 out of 5
Extension Builder in St James
"Stylish Kitchen & bathroom Fitting Service with prices guaranteed between £4000 to £5000, you can trust us to deliver top-notch service Transform your kitchen into a modern masterpiece with Quality Builders Limited! Our reliable team specializes in fitting any kind of stylish Wren B&Q kitchen, complete with gas cooker, washing, and cooking machine connections.
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Latest review:
Quality Builders completed a remarkable domer and loft conversion for us on 2/10/2023, and we couldn't be more pleased with the results. From the outset, their professionalism and attention to detail were evident. The initial consultation was thorough, and they took the time to understand our vision for the space. Throughout the project, communication was excellent, with regular updates on progress and any necessary adjustments. The craftsmanship displayed by Quality Builders was exceptional. Every aspect of the conversion, from structural work to finishing touches, was executed with precision and care. Their team of builders and contractors demonstrated expertise and skill, resulting in a finished product that exceeded our expectations. Not only did Quality Builders deliver on time, but they also adhered to budgetary constraints without compromising quality. Their transparency and honesty throughout the process gave us peace of mind and confidence in their abilities. The transformation of our space is truly remarkable. The addition of the domer and loft has added both aesthetic appeal and practical functionality to our home. The new space is light-filled, spacious, and seamlessly integrated with the existing structure. Overall, we cannot recommend Quality Builders highly enough. Their commitment to excellence, attention to detail, and professionalism set them apart in the industry. If you're considering a home renovation project, look no further than Quality Builders for exceptional results.
GRAND DESIGNS INTERNATIONAL LTD
Rating: 5 out of 5
Extension Builder in St James
Grand Designs International (GD) | Architectural, Engineering & Construction Services At Grand Designs International (GD), we are dedicated to delivering high-quality architectural, engineering, and construction services tailored to meet our clients’ unique needs. Backed by over 20 years of expertise, our team specializes in transforming visions into reality—whether you're planning a new build, home extension, loft conversion, or full-scale renovation. With a strong foundation in innovation, sustainability, and precision, we provide end-to-end project solutions, from initial design and planning permissions to structural calculations and final construction. Our commitment to quality, efficiency, and client satisfaction ensures that every project is completed to the highest standards. Why Choose Grand Designs International? ✅ Full-Service Expertise – From architectural planning to construction, we handle every stage seamlessly. ✅ Planning & Building Regulations Specialists – We navigate approvals efficiently to prevent delays. ✅ Experienced & Certified Team – Qualified engineers, architects, and builders with a proven track record. ✅ Tailored Solutions – Every project is custom-designed to meet your style, space, and budget needs. ✅ Transparent Pricing & Project Management – No hidden costs, just reliable service with regular updates. ✅ Fast Turnaround & On-Time Delivery – We work efficiently without compromising quality. Our Services 🏡 Architectural & Planning Services Planning Applications & Building Regulations Approval Concept & Detailed Design Interior Design & Space Planning 3D Visualizations & Rendering Enforcement & Retrospective Planning 🏗️ Structural & Engineering Design Structural Calculations & Drawings Civil & Structural Engineering Services Quantity Estimation & Cost Planning 🔨 Construction & Building Services Home Extensions & Rear Extensions Dormer Loft Conversions & Flat Conversions New Build Homes & Full Renovations Project Management & Site Supervision Construction Planning, Procurement & Logistics Quality Control & Safety Management At Grand Designs International, we believe in delivering excellence, one project at a time. Our reputation for integrity, professionalism, and top-tier craftsmanship makes us the preferred choice for homeowners and businesses across London and beyond. 📞 Get in Touch Today! Let’s discuss your project and bring your dream home to life.
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Latest review:
★★★★★ Highly Recommended! I had an existing 3-bedroom rundown property and contacted multiple builders before meeting Director Mr. Q Nawaz. From our first meeting, I was impressed by his ideas and the fact that Grand Designs could provide all services in-house. Initially, I proceeded only with the planning application to see if what he promised was possible—and YES, he delivered! My application was approved as he assured me. Seeing this success, I entrusted them with the entire construction project, and Grand Designs completed it within just 6 months, despite the challenges of COVID-19. Not only did they build my project, but they also added significant value to the development. I’m proud to have worked with them, and their exceptional work on my St Albans development is now featured in their portfolio. Within one year, the value of my property increased by £500,000—a testament to their expertise! Extremely professional, highly skilled, and very reasonably priced. You don’t need to go anywhere else—Grand Designs is the complete package!
Alan Lancaster Ltd
Rating: 5 out of 5
Extension Builder in St James
Alan Lancaster Ltd is a professional painting and decorating company dedicated to delivering high-quality finishes and exceptional service across residential and commercial projects. Based in North London, we have built a reputation for reliability, craftsmanship, and attention to detail. Our team comprises skilled tradespeople with years of experience, allowing us to offer a full suite of home improvement and refurbishment services beyond painting and decorating. Whether it's a fresh coat of paint or a complete property renovation, we handle every project with precision and professionalism.
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Latest review:
Restoration & Refurbishment- 18 May 2026
William and his team did a great job of redecorating our 4 bed period property inside and out. William gave a detailed quote which enabled us to select or deselect some items and know the relevant cost. There were some minor snags that required extra plastering and repointing all handled with ease and no fuss. The communications were good and the team were hard working and courteous. I would not hesitate to use William again.
House Refurb
Rating: 4.9 out of 5
Extension Builder in St James
We have built our livelihoods on remodelling people’s homes, increasing their size and value. From the simple to the lavish, no matter how big or small, we’ve experienced it all and we can help you every step of the way offering a comprehensive service and take care of all aspects of your project, from initial plans through to full completion. Our skilled workforce of reliable professionals is on duty to offer you quality building work, competitive prices and exceptional customer service.
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Latest review:
Extensions- 24 Feb 2014
Narcis and his team listened carefully to my specifications and completed the job with an excellent finish. Throughout they were courteous and hard working. Highly recommended .
SM FULHAM BUILDERS LTD
Rating: 5 out of 5
Extension Builder in St James
Welcome to SM FULHAM BUILDERS LIMITED. We are reliable, professional business team dedicated to designs and finishes of the highest quality. We are based on south west London and cover the surrounding areas. Having over 15 years of experience we offer full range of internal and external services from minor jobs to full home refurbishments. We offer a tailored, friendly and professional service to very high standards and pride ourselves on quality, reliability and reputation.
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Latest review:
He's very professional and knowledgeable in interior construction. We highly recommended him.
P.S. Building Projects Ltd
Rating: 5 out of 5
Extension Builder in St James
"WE ARE A HOME EXTENSION AND LOFT CONVERSION SPECIALIST. WE ALSO OFFER A COMPLETE BUILDING SERVICE! A family-run business, Quick growing building company with more than 20 yrs building experience. And we’ve been providing the highest quality work for our customers ever since. Everyone here at P.S.Building Projects Ltd is dedicated to meeting your specific requirements, delivering bespoke work on budget and on time. Which means you’ll enjoy peace of mind from start to finish."
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Latest review:
Conversions - General- 11 Oct 2022
We've been seriously impressed with Pawel and his team. They opened up our rear dining room/kitchen wall using an RSJ, following our engineer's drawings perfectly. They also did a few bits of plumbing and bricked up one of the windows at the rear, which is where the new kitchen will be fitted. They were incredibly tidy and really pleasant and courteous to be around, which my wife was so grateful for given we live in a busy family house (most builders are not like this...), I can't thank them enough! We will definitely be using them again in the not-so-distant future!
We will do
Rating: 5 out of 5
Extension Builder in St James
We are here with a lot of experience to help you for any construction job as soon as possible at the best possible price.
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Latest review:
Kitchen Fitting- 10 Oct 2024
Farhoud and Sam did a great job, really fast. Thanks, Guys!
first4builders
Rating: 5 out of 5
Extension Builder in St James
Loft conversions, house extensions. All kinds of renovation and refurbishment: doors and windows, flooring, tiling, bathroom and kitchen fitting. Building with confidence!
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Latest review:
MR ZAIKA DID A BIG JOB FOR ME,WHICH HE FINISHED IN GIVEN TIME .HE BUILT A REAR EXTENTION,AND DID RENOVATION SUCH AS FLOORING,REMOVING AND INSTALLING DOORS,TILING,REMOVING AND CHANGING WINDOWS,BUILDING A NEW KITCHEN,AND BATHROOM.HE WAS RELIABLE AND DID EVERYTHING TO THE BEST OF HIS ABILITY AND AS HE HAD PROMISED. HIS WORK IS EXTREMELY PROFESSIONAL AND CLEAN I AM VERY HAPPY WITH MR ZAIKA'SWORK . I WOULD RECOMMEND MR ZAIKA HIGHLY AND I AM SURE ANYONE GIVING HIM WORK WOULD BE VERY HAPPY AS I HAVE BEEN.
Olgert Doko
Rating: 4.8 out of 5
Extension Builder in St James
My name is Olgert and my team and I are ready to give you a quote, on any building needs - painting, plastering, tiling, roofing, extensions and many other services. We are friendly, reliable and professional and we care about our work. Give us a call today for a free quote. We are located in North West London and we have more than 15 years experience in construction.
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Latest review:
Tiling- 15 Sep 2021
Very professional and helpful from the beginning to the end. Great work, tiling was finished on time and to a great standard. Our new restaurant floor looks great and customers love the new look. Would definitely recommend and will use again. Thanks Team Doko
Made Construction Simple Ltd
Rating: 3 out of 5
Extension Builder in St James
At Made Construction Simple we value the high-quality craftsmanship and impeccable service we provide for each and every one of our customers. With a wide range of construction services available, our team of experts are always on hand to provide property perfection
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Latest review:
Attended property, went to church thinking he'd start, returned to empty house no work done. let me down. bad service
D&C Building
Rating: 5 out of 5
Extension Builder in St James
Top quality, reliable team and always in time !
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Latest review:
Fencing- 9 May 2022
Very nice and polite guy. He did his job as promised. The price was fixed and job was done neatly. He tidied away all the rubbish and out back everything in order which I was very pleased with. The communication was great and everything went very well. We enjoy our garden more than before now.

4.2

Top rated Extension Builders

Our Extension Builders in St James, are rated 4.2 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.