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

3593 Results

Sort by:

Reva Projects Ltd
No reviews yet
Extension Builder in St James
We take pride in offering outstanding quality services in an array of sectors in which we operate. With over 25 years of experience in the building industry, our highly experienced team ensure a comprehensive and uniquely personal service, embracing both public and private work in the residential and commercial sectors.These include design, planning and construction of residential and commercial projects. We provide an unmatched level of service from the first enquiry until final handover.
Get in touch
SRK Constructions London Ltd
Rating: 5 out of 5
Extension Builder in St James
We offer a plethora of construction services and are known for excellent k-rendering, electrical fitting, plumbing, and carpet service. We have been in the industry for more than 14 years and our work varying from small to large projects speaks about our experience in the field. We believe in creating with heart and building with the mind. We are trustworthy contractors and always strive to meet the quoted budget. Clients’ satisfaction is the topmost priority of the SRK constructions.
Get in touch
Latest review:
Bathroom Fitting- 12 Apr 2022
Sandeep was the first builder who I ever met who finished job before time . His team has worked very hard and did job as per our expectations . Before this I used 3 different builders and no one finished job on time . I will recommend him for any building related job .
Bulbuilder
Rating: 4 out of 5
Extension Builder in St James
I am from Bulgaria.
Get in touch
Latest review:
Lovely father son business, professional, friendly guys. I asked them to build a plasterboard wall in order to create an extra bedroom in my house, the wall was finished well, within two days and they charged me a very reasonable rate, as a young women in business I find that tradesmen often try to overcharge me but these gentleman did not. They also took a look at leak that had occured which another professional plumber failed to solve and tried to charge me over £200 just to take a look! I have and will book them on a number of other jobs.
Emerald london building solutions fixed
Rating: 4 out of 5
Extension Builder in St James
Refurbishment and building contractors/carpentry Contractors we are master builders and a reputation of being excellent at a reasonable Price all work is backed by guarantee on all works
Get in touch
Latest review:
Restoration & Refurbishment- 15 Jun 2020
Left the job unfinished after many days of chasing to complete. Quality dependent on individual tradesman. Initially good quality but other workmen poor. In the end I had to throw them offsite.
Building life uk limited
Rating: 4.8 out of 5
Extension Builder in St James
My skills are :Tiling :brickwork :extensions :loft conversions :partition : painting :carpentry E.t.c :you name it we do it I've got a team together who are hard working men who are very motivated on working together with our clients we always keep everyone who we do work for happy and still get recommended I work references that I can provide (We haven’t been online at my builder over a year now but we have been working out from my builder we got lots of work to prove)
Get in touch
Latest review:
Bathroom Fitting- 9 Oct 2018
Ozay arrived on time and finish the job to a high standard I've used the shower for over a month now and no leaks! Would use again!
Asiya properties Ltd
No reviews yet
Extension Builder in St James
We are experienced in new build extensions basement loft, foundation ground work & renovation
Get in touch
SpectRoom property Maintenance LTD
Rating: 5 out of 5
Extension Builder in St James
At SpectRoom Ltd we pride ourselves for being prompt, working to budget and on time and are very clean. We will fully complete any project including all decorating flooring tilling construction and all other property maintenance jobs to customer requirements and for that we will be more than happy to provide local references. SpectRoom for spectacular rooms.
Get in touch
Latest review:
Extensions- 22 May 2019
Jacob was very accommodating and flexible. His team were great and he completed the work nicely. There was some splatter from the cementing on to my neighbour's wall. He tried to clean it off but it wouldn't all come off. Therefore, he went out and bought some paint and repainted their wall. I would get him back for more work without hesitation. When looking for a builder - they have to be honest, work hard and to an excellent quality without cutting corners. They should be responsible to ensure neighbours property isn't damaged and provide consultancy as what we want and want is realistic can differ significantly! - and if any issues rectify them once the job is complete and of course provide good after sales. I have used several builders over the years - very few tick all of the above boxes. Jacob certainly does.
PK Decorating & Building Services LTD
Rating: 5 out of 5
Extension Builder in St James
At PK Decorating and Building Services we are committed to deliver the highest standards of quality in everything we do.Make the most of your property with high quality work, done the way it should be; fantastic workmanship, client communication and ensuring everything is clean and tidy when the work has been completed.While PK Decorating and Building Services is based in South London, we can deliver our services across London and the surrounding areas.If you have any questions please contact us
Get in touch
Latest review:
Conversions - General- 14 Jul 2026
PK decorating and building were professional and reliable. The craftsmanship was excellent. The manager and foreman managed job very well. I would highly recommend them.
QBS Property Maintenance LTD
No reviews yet
Extension Builder in St James
We QBS Property maintenance LTD are the leading maintenance company with over 40 years experienced provided amongst our team. We specialize in full property renovations, bathroom fittings, gas & heating jobs, plumbing, carpentry, extensions, loft conversions, roofing. You can count on us to provide an excellent and cost affective solution.
Get in touch
Saryal Construction Ltd
Rating: 5 out of 5
Extension Builder in St James
A team of skilled and experienced workers operating efficiently and producing effective results that are appealing and catered to customers' needs. Non-VAT company. Competitive prices benefit. Feel free to get in touch for full house refurbishment or part refurbishments like bathroom/kitchen/bedrooms. Other project we take on are garage conversions, and projects like tiling, carpentry, roofing. https://linktr.ee/saryalconstruction
Get in touch
Latest review:
Bathroom Fitting- 22 Jul 2026
Fantastic work by sundeep and his team. Arrived on time, cleaned up after themselves and did a very good job.
Omniscient Construction Ltd
Rating: 5 out of 5
Extension Builder in St James
We have 20 years experience in construction,from extensions,loft conversions,property maintenance,kitchens,bathrooms,basement conversions,through to new builds. We work closely with our clients to achieve their goals. We have a trusted workforce.
Get in touch
Latest review:
Extensions- 6 Apr 2018
Excellent in all departments
Builders World Supplies Ltd
No reviews yet
Extension Builder in St James
The company specializes in total home or flat renovations and house extensions. The team has actively participated in both large and small scale construction projects in London over the last 15 years. The quality of the work is outstanding and we can fit any budget. Our experience and our extensive contacts in the industry enable us to offer solutions suitable for the customer's needs. The founder and Director of the company is a qualified Civil Engineer.
Get in touch
Area Property Care LTD
No reviews yet
Extension Builder in St James
If you are looking for a company providing comprehensive construction and renovation services we have the skilled team. Area Property Care provides refurbishments in general and construction of extensions and loft conversions. Engineers on the road help clients for small repairs / maintenances. We cover London area. Please contact us and get a quote for free.
Get in touch
Jim building services ltd
Rating: 5 out of 5
Extension Builder in St James
Great Team over 20years experience, we specialise in Lofts, Extension, Bathrooms, Kitchen & Full Refurb, We pride ourselves in what we do, we are dedicated team consentrating a project at the time making sure always deliver Quality & ontime. Clean,tidy & attention to detail panctual, always friendly & great costumer care Thank you
Get in touch
Latest review:
Extensions- 30 Dec 2024
I am extremely happy with Jim and team's work. Their work is of high quality and they give attention to details too. I received a lot of positive feedback from friends/family on the extension work they have done. I can confidently say that he's delivered a quality work for a very reasonable price. Jim consulted us throughout the building process making sure we're happy with the decisions. If he found out anything outside the project work, he'd inform and fix it. I agreed to carry out some additional work including front side rendering, bathroom refurbishment and changing some internal doors. He completed all additional work timely and for a reasonable price. I highly recommend Jim for any building work. I'll be going with Jim for any building project in the future.
Jnnybyte Ltd
Rating: 5 out of 5
Extension Builder in St James
At Jnnybyte Ltd, we deliver high-quality building and renovation services with a commitment to exceptional workmanship, reliability, and customer satisfaction. Whether you're updating a single room or undertaking a full property renovation, we provide a professional, end-to-end service tailored to your needs. Our services include: Full home renovations & refurbishments House extensions & structural alterations Kitchen & bathroom installations Wall & floor tiling Plastering, decorating & painting Bricklaying & masonry Plumbing & electrical work Waterproofing & insulation Decking, fencing & landscaping General building & property maintenance We believe every project deserves careful planning, honest communication, and meticulous attention to detail. We work with trusted materials, follow industry best practices, and ensure every job is completed safely, efficiently, and to a high standard. From the initial consultation through to the final finish, we keep you informed at every stage, respect your home, and leave the site clean and tidy. Our goal is simple: deliver quality workmanship that adds value to your property and gives you complete peace of mind. If you're looking for a builder who is reliable, professional, and committed to getting the job done right the first time, Jnnybyte Ltd is here to help. Get in touch today to discuss your project and receive a free, no-obligation quote.
Get in touch
Latest review:
Kitchen Fitting- 16 Jul 2026
Excellent communication. Excellent service. Excellent results. Highly recommend!
WM Design & Build
No reviews yet
Extension Builder in St James
I have a lot of experience in construction field. I work with my dad and cousins and we do all type of works. Professional and always on time.
Get in touch

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.