Extension Builders in St James

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4.2 (20 reviews)

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

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 St James

3589 Results

Sort by:

The00company
Rating: 5 out of 5
Extension Builder in St James
Independent family business taking pride on our reputation for a unique combination of workmanship and service regardless of the size of project. My team and I are customer-oriented providing you with quality products built to your exact specifications in the specified time period. We provide a personalised service that involves you in all design and planning.
Get in touch
Latest review:
Khin and Senh did an amazing job redoing all the skirting in our home. Their quote was competitive and their workmanship outstanding. They helped us source the materials to our specification for a great price, handling all the delivery details and were happy to pick up any bits and bobs to get the job done. Each day they arrived on time and often worked late to accommodate the fact we had carpets coming in the following week. After each day tools and materials were squared away and they would send updates on progress. The final product was top quality and has nicely finished off our home as part of a large book of renovations. Finally any snags that I did notice they were happy to come back and address, I couldn’t have wished for any more from these guys. All the best !
Abdullah azouz.
Rating: 5 out of 5
Extension Builder in St James
I’m involved in residential property development. My role includes supporting construction projects, coordinating with teams, and helping ensure work is completed efficiently, on time, and within budget.”
Get in touch
Latest review:
Bathroom Fitting- 23 Apr 2026
Rapid response and professional work.
alpha green construction
Rating: 5 out of 5
Extension Builder in St James
I have 25 years experience in the trade.specialise in innovation and reliability. Trade built company generally around masonry , roofing and all other structural undertakings. We specialise in loft conversions and house extensions , masonry and landscape gardening. We also provide design and build schemes for the above topics.
Get in touch
Latest review:
Extensions- 14 May 2019
We love Berry, he has followed our project from the beginning to the end and he has been there all the steps of the way. He listened to our ideas and enriched them with more of his adding his special attention to details skills. For every problem, we had along the way he talked to us making sure we were happy with alternative solutions. Plus he is able to create a friendly working environment which makes the invasion of your house less intrusive, he has been very respectful of our space. We can genuinely say that he has gone beyond our expectations, and will be very happy to do future works with him. Luca and Nick
Global32 Construction Ltd.
Rating: 5 out of 5
Extension Builder in St James
We're a London-based construction company dedicated to delivering projects of all sizes with utmost care. As proud members of the Federation of Master Builders (FMB), our highly skilled and professional team in construction and project management is here for you. Discover a world of construction possibilities with our comprehensive range of services tailored to meet your needs. From envisioning and crafting stunning new builds to revitalizing existing properties through renovations and conversions, we're dedicated to bringing your vision to life. Our expertise extends to interior design and fit-outs, ensuring that every detail reflects your unique style and functionality requirements. We specialise in both residential and commercial projects. Backed by our meticulous project management, you can trust us to deliver on time and within budget. Our consultancy services provide invaluable guidance at every step. Whether it's groundworks, landscaping, or ongoing maintenance, we're here to turn your construction dreams into reality. Beyond residential work, Global 32 Construction also has solid experience in commercial projects. Whether you’re refurbishing an existing space or starting something new, our team can handle both the technical side and day-to-day coordination to keep things running smoothly. We’ve worked on a range of spaces including hair salons, F&B outlets, and other retail units, so we understand the practical needs behind each project, from layout and workflow to compliance and finishing details.
Get in touch
Latest review:
My house was old and its condition was poor. Much were needed to be fix. The original kitchen layout were also inconvenience to my wife. I need to have all these changed under limited time. This builders have a team of specialists on almost every aspect. They gave me variety on the layout design and choose of materials. This saved me money, time and tons of trouble to find difference contractors. The after service and their respond time are very good too. I hope by sharing my happy experience can save your money and trouble to find a good contractor.
Archdom.ltd
No reviews yet
Extension Builder in St James
We are a design and build company with expertise in architectural, interior design and construction. Offering a complete service from design to final build. We develop the full potential of your space and build it to perfectly match our design.
Get in touch
Rayway limited
Rating: 5 out of 5
Extension Builder in St James
Over 15 years of experience in building and construction industry
Get in touch
Latest review:
Restoration & Refurbishment- 18 Feb 2021
Ray was an absolute professional. He fitted a new downstairs toilet which required a new soil pipe and associated groundwork as well as new stud walling to partition the space. He did most of the work himself, but brought in others for the pieces where he wanted an expert. He was flexible to small changes and was happy to take on additional work when unforeseen issues were discovered. The areas he had worked in were quickly cleaned before he left each day. Overall the work was completed to a good quality and at a reasonable price.
CONSTA Construction Limited
Rating: 4.6 out of 5
Extension Builder in St James
CONSTA Ltd - small construction company based in London, and characterises in flexibility to complete various jobs . There is list of different small or awkward completed jobs in our portfolio as well as more significant projects as loft conversions, extensions, full house reconstructions, new build and Passive House construction as well.
Get in touch
Latest review:
Extensions- 29 Aug 2021
Communicated well at the start with reasonable cost. work was done well but the finishing was not so great as expected. The end cost was very expensive. Charged by the hour, the team were very slow which was upsetting to see me pay for time where they sat around not doing much. Ensure to agree fixed price. Communication after job is poor, double glazing has warranty which now not being able to communicate with kostas having to pay to get things done that should be covered in warranty. Central heating give huge problems. Do not use for big jobs
Kaseno Group LTD
Rating: 5 out of 5
Extension Builder in St James
Our company is based in London. We do all aspects of the construction. Our main target is to achieve the finest quality of our services and to satisfy any of the clients' requirements deliver the project on time and achieve a reasonable price.
Get in touch
Latest review:
Kitchen Fitting- 19 Jan 2019
Very good, professional ,trustworthy team.I can recommend them to anybody. Their communication was excellent. The work they have done is of high stardard and was done on time.
RS building
Rating: 5 out of 5
Extension Builder in St James
We’re a highly professional team with over 20 years’ experience in extensions, loft conversions, high-end renovations, new builds, and property conversions. We deliver top-quality work on time and within budget. Our rates are among the most competitive in the UK at £180 per day per man + 10% OHP. With all specialist trades under one umbrella, we can handle projects of any size smoothly—from £20k up to £2m. Happy to discuss your project further
Get in touch
Latest review:
RS Building successfully delivered two full back-to-brick refurbishments and a new-build development for us in Greenwich, including demolition and construction of four new dwellings. Their level of workmanship is exceptional, and their attention to detail is second to none. As experienced property developers, we’ve worked with many contractors—but RS Building stand out for their reliability, quality, and professionalism. We have since recommended them to several colleagues, all of whom have been equally impressed. Our only regret is not finding them sooner. We look forward to working with them again on future projects.
Valentin
Rating: 5 out of 5
Extension Builder in St James
Extension, plastering, tiling, flooring, plumbing, electric.....General contractor
Get in touch
Latest review:
Bathroom Fitting- 1 Jun 2024
Valentin is a very professional and well experienced plumber and electrician. Hi did amazing job.Changed the bath and the panels in one day!
Ajila Limited
Rating: 4.5 out of 5
Extension Builder in St James
Ajila Limited is a professional construction company specializing in house refurbishment. With a commitment to quality craftsmanship and attention to detail, we transform homes to meet the highest standards of functionality and style. Whether it's a full renovation or specific improvements, our experienced team delivers exceptional results that enhance both the beauty and value of your property. The company engages in multiple trades which includes plumbing, kitchen, bathroom, tiling, extension, home refurbishment etc
Get in touch
Latest review:
Plumbing- 2 Apr 2025
Great service and good price. Thank you
Amir
No reviews yet
Extension Builder in St James
I’ve been in this trade for around 10 years
Get in touch
Orama Group Ltd
Rating: 5 out of 5
Extension Builder in St James
Orama is the family run Construction Company of choice, for large and small scale projects operating throughout London. Offering a bespoke service and setting new standards in the construction industry.
Get in touch
Latest review:
I originally contacted Joe from Orama to fit a new kitchen for me. When he came to give me a quote, I hadn't yet chosen what I wanted. He really took the time to make several recommendations and so I decided to go ahead with him to design my kitchen fully and fit it. The team were so easy to work with and most importantly respectful in my home! Their attention to detail is second to none. He really understood the style I liked in one conversation. The finish is flawless. I highly recommend them!!
Buildleader
Rating: 5 out of 5
Extension Builder in St James
Our home refurbishment company BUILDLEADER is based in London. We offer full house renovation requiring extensive electrical, plumbing and structural work. All of our tradesman are professionals with over 15 years of experience who get the job done on time, on budget, and to the highest standard. We handle every project with the utmost competence and respect.
Get in touch
Latest review:
Bathroom Fitting- 28 Mar 2022
Good plumber, call them in for shower replacement
Delta Construction Limited UK
Rating: 5 out of 5
Extension Builder in St James
We are commited to our clients. We have experience in working with bespoke clientele and are very confident in our capabilities, expertise and delivery of final product as well as after care.
Get in touch
Latest review:
Decking- 23 Apr 2025
I needed someone reliable and efficient. Artan responded quickly to messages, was very polite, hard working and cleaned the area after the job. Stress free experience for me which was fantastic. Would recommend and definitely hire again. Thank you so much Artan!
A&A BUILDING SERVICES LTD
Rating: 5 out of 5
Extension Builder in St James
A&A Building Services Ltd provide high-quality construction, refurbishment and general building services across North and West London. With all major trades under one roof, we deliver seamless project management from start to finish - saving clients time, hassle and additional contractor costs. While we cover all aspects of building work, we are specialists in bathroom renovations and premium residential refurbishments. Our team combines 20+ years of hands-on industry experience with modern standards of workmanship, communication and care. Built on quality, dedication and trust, we take pride in delivering projects that are finished to a high standard, on time and with transparency throughout. We work with homeowners, landlords and commercial clients, offering both planned works and emergency call-outs. Why choose us: -All general building trades covered -Bathroom renovation specialists -20+ years combined expertise -NIC EIC & Gas Safe contractors -Fully insured (Public Liability £5 million) -Free quotes for small projects / estimates, paid surveys for larger works -Warranties & guarantees provided -Emergency and out-of-hours service available Whether you’re refreshing a single room, renovating your home or planning a larger refurbishment, A&A Building Services Ltd deliver results you can rely on. Contact us today for your free quotation.
Get in touch
Latest review:
Tiling- 17 Feb 2026
wonderful job! hired afterwards for additional building service, fitted a whole bathrooms with tiling and a complete installation of sound proofing, floor insulating etc for a bedroom all of a high quality. great team to work with

4.2

Top rated Extension Builders

Our Extension Builders in St James, are rated 4.2 out of 5 based on 20 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 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.