Extension Builders in Welwyn

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 3.9 (15 reviews)

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Some of our top rated extension builders in Welwyn

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Gary prime
Rating: 4.5 out of 5
Extension Builder in Welwyn
I have been actively involved in the construction industry for the past seven years, during this time I have gained experience in ground works, bricklaying and a variety of other trades and in the last two years I have been working in a supervisory role. I have worked on large construction sites as well as carrying out works on property refurbishments.
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Latest review:
Groundwork & Foundations- 14 Aug 2019
Gary did an excellent job on the drainage, everything I asked of him. He was punctual and polite, wouldn't hesitate to hire him again.
Sam plumber
Rating: 5 out of 5
Extension Builder in Welwyn
I'm very good plumber.I'm correct with the customer never have problem back
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Latest review:
Bathroom Fitting- 2 Jun 2026
Amazing work, Sam and his team are dedicated professionals that have real eye for detail. The toilet needed changing position which required a significant amount of rework of pipes. But they made it look easy.. tiling work was done perfectly and Sam helped me find the right products before starting this project. Really happy with the work done and was completed in a timely manner. Highly recommend.
D Bird carpentry and building LTD
Rating: 5 out of 5
Extension Builder in Welwyn
Hi were Dbird Carpentry & Building we are a family run company by myself Daniel and my brother Ellis. We take pride and love what we do! We will help you every step of the way through your project no matter the size.
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Latest review:
Conversions - General- 21 Jun 2022
D Bird Carpentry completed the works on time and to a high standard. Dan and his team were a pleasure to work with and I would be happy to work with them again.
Team build
Rating: 5 out of 5
Extension Builder in Welwyn
A small family team but with a great big attitude to quality, value and service. Residential refurbishment,remodelling and extension. A passion for developing property ourselves with a number of projects underway.underpinned with effective design and solid processes to give our clients s confidence that the end result wilI be just as expected.
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Latest review:
Alex and his team are were fantastic from start to finish. I’m really happy with my loft conversion and love some of the ideas they came up with to help maximise the space. The finished result honestly is more than I ever expected with the small added details. Again Thankyou Alex and team for all your hard work
SJM Bespoke Carpentry & Construction
Rating: 5 out of 5
Extension Builder in Welwyn
Hi, my name is Stuart Milner and I am a carpenter by trade with over 25 years experience and have taken on many roles during that time from site foreman to project manager and have picked up many different skills and knowledge that cover most of the building industry. I would like to say I am precise in my way of working and always work with the Customer through the different processes to make sure we arrive at the result they want.
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Latest review:
Extensions- 18 Jul 2023
We used Stuart to carry out some alterations to our kitchen, convert our garage & construct a link between the two. From the moment Stuart quoted us for the work I was struck by how diligent he was, coming back to discuss his quote & being very clear in everything he had included & equally anything that wasn't. We were delighted that his diligence & care extended throughout the project & to the work that he did, he clearly cared that everything was done correctly, as if it were his own home. He put thought into everything he did & the sequencing of the work, making sure there was as little disruption to us as was possible. He also communicated to us throughout about his plan and any issues he encountered. We are thrilled with the end result, Stuarts work is of a high standard & competitively priced too, I couldn't recommend him highly enough.
BFL Builders Ltd
Rating: 5 out of 5
Extension Builder in Welwyn
Affordable. Reputable. Quality. For more than 10 years. BFL Builders LTD. Is a family run business based in Beds, Herts & Bucks that cover all trades from Flooring to full Refurbishment. We pride ourselves on Quality work done at fair prices. Our skills include: Extensions and renovations Garage and loft conversions Plumbing and electrics Roofing and guttering Driveways and block paving Fencing and Landscaping Plastering and damp proofing All flooring and tiling AND MANY MORE
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Latest review:
Plumbing- 7 Mar 2021
Very friendly and professional guy. Got the job done quickly and at an affordable price. I would use his services again and would recommend him to others!
T De Maio Brickwork services
Rating: 5 out of 5
Extension Builder in Welwyn
Our aim is simple, Obtain repeat business and recommendations by providing customer focused services, producing high quality work on time and within budget. Please take a look at my photo gallery of the work myself and the team can produce, our work speaks for itself👍 Kind regards Tony De Maio
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Latest review:
Bricklaying- 28 Jul 2019
With me having no previous experience and knowledge. Toni was helpful and I felt that what ever I asked Toni to do, he could provide. I trusted him completely with what I asked, and he was the best quote by far. Toni helped with where to purchase what was needed and was clear and transparent throughout. I am even thinking of having more work done now I know what can be produce.
Mevlan & Sons
Rating: 5 out of 5
Extension Builder in Welwyn
Mevlan & Sons is a trusted building company with 10 years of experience in residential construction, specializing in custom homes, renovations, and remodeling projects. With years of experience, we bring a commitment to quality craftsmanship and attention to detail on every job, big or small. Whether you're building your dream home from the ground up or looking to renovate your current space, our dedicated team works closely with you to ensure your vision becomes a reality.
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Latest review:
Good price for complete new bathroom. No issues found when stripping out the old one so they finished on schedule. Came recommended by a friend of a friend kind of thing and glad they were. Got another little job now for them when the weather improves. Good job.
Walker Building and Carpentry
Rating: 5 out of 5
Extension Builder in Welwyn
I’m a carpenter and general builder who’s been working in and around the local area with 15+ years experience, I’m hard working, friendly, reliable and I take a lot of pride in my work. I am family man at heart who enjoys sharing my passion for football with my son, reading with my daughter, and when I get a chance enjoy the odd pint in the local pub.
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Latest review:
Carpentry- 21 Jan 2020
The job that Thomas Walker completed for me was an extremely difficult, however he was an excellent professional and completed the job which exceeded my expectations. He also offered to help with getting discounts on materials. I would definitely recommend A***
Martini Building & Roofing Ltd
Rating: 5 out of 5
Extension Builder in Welwyn
I do Building and construction since 2010 Quality is our priority
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Latest review:
Tiling- 29 Jun 2022
We needed an experienced and skilled tiler, to fit 800 x 800 glass fronted tiles to a TV wall. The tiles were manufactured to size, and formed one large pattern. Arben did a fantastic job for us, he finished the job in one day, and it was completed to a excellent standard. I highly recommend him!
Phi Architectural Services Ltd.
Rating: 5 out of 5
Extension Builder in Welwyn
Phi Architectural Services Ltd. specializes in providing architectural, structural and project management services from small to big sized residential projects. With more than 12 years of experience and more than 500 projects ranging from refurbishment to new build houses and flats, the firm also have its own team of sub-consultants and contractors.
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Latest review:
CAD / Drawings- 6 Mar 2022
Very helpful architect. Needed a little nudge occasionally due to busy season, but the work is delivered in time and to a high standard. I'm happy with the result.
CVD Constructions
Rating: 5 out of 5
Extension Builder in Welwyn
Hi I'm new as a solo trader with a vast experience in multiple trades I have a team of plumbers and electricians if needed.
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Latest review:
Conversions - General- 8 Oct 2022
Valentin, Dan and Chris did a great job turning an old wooden shed into a beautiful teenage den / home office. They stripped the shed down to the original wooden frame, replaced the roof and cladding, subdivided the internal space into two rooms and a small shower room. The job was reasonably priced though there was a little scope creep much of it due to additions to the original specification that resulted in an increase in price. With hindsight we should have made sure we kept track of additional work. They were friendly, tidy and considerate in the work and the dog loved having them around. They were professional and hardworking and we were pleased with the final result which was excellent value for money. We would recommend Valentin and his team and will have them back to do more work for us.
UTOPIAN BUILD LTD
Rating: 5 out of 5
Extension Builder in Welwyn
BMA Home Solutions ltd are a home improvement company. Carrying out various projects from fencing and landscaping through to loft conversions and renovations. With a combined team experience of over 200 years you can ensure that you are in safe hands. We look forward to hearing from you.
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Latest review:
Fascias & Soffits- 24 Jun 2022
We hired BMA Home Solutions to pave our walkway, mend our Fascia board and more. Bradley, Andy and the rest of the team carried out an excellent job- we were very happy with the finished work. The team were punctual, polite and very professional. The team were also very flexible and fair when we wanted to make changes. I would hire the team again for future work and I would also recommend them to others.
JC Group Property Sevices LTD
Rating: 5 out of 5
Extension Builder in Welwyn
JC Group Ltd is a reliable and experienced building company offering bathroom installations, plumbing, home extensions, and general building works. With over 30 years of combined industry experience, we take pride in delivering high-quality workmanship, clear communication, and projects completed on time and within budget. We are committed to customer satisfaction and maintaining the highest standards on every job, no matter the size.
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Latest review:
We’re absolutely delighted with the extension and the overall experience from start to finish. The workmanship is to a very high standard, and everything was completed professionally and on schedule. Communication throughout the project was excellent, and we were kept informed at every stage. The team were reliable, tidy, and respectful of our home, and the finished extension has exceeded our expectations. We wouldn’t hesitate to recommend them to anyone looking for quality work and a stress-free build.
Korab Builders Ltd
Rating: 5 out of 5
Extension Builder in Welwyn
Having completed many successful projects, we have the experience and the expertise needed to fulfil majority of our client wishes. We provide vast range of services: •new builds •extensions •conservatories •loft conversions •converting office premises into flats •refurbishment •plumbing •electrics •plastering and decorating •fitting kitchens •fitting bathrooms •tiling •landscaping and paving
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Latest review:
Restoration & Refurbishment- 20 Oct 2022
I contacted Korab to remove my chimney breast, he came to have a look, quoted me for the job and then started the work. Once the work was completed I was over the moon with the work that Korab and his team had done and the service they provided and I asked them to have a new full refurbished house (new electrical work, new plumbing, new plasterboards, new skimming, new doors, new laminate flooring, new tiles, new skirting boards,new bathroom), side extension (which korab helped me to design)and garden patio and a new front garden wall. Korab was a very friendly and easy-going person from the moment I met him in regards to my first project (the chimney breast). He would pay attention to every detail and always ask if I was happy with the work which was being carried out. Korab and his team would always ensure that the work space was left clean. Korab and his team were more than happy to have an input and make suggestions when I needed them too, he also make me feel comfortable to ask any question. Korab and his team did an amazing job in my house and completed the work to a high standard in which I was so happy about. They truly are an experienced group of guys and I would highly recommend them to anyone. What a pleasure it was to have met them. Thankyou once again!
Laurentiu
Rating: 5 out of 5
Extension Builder in Welwyn
I have achieved experience by working in complete house refurbishments and as a contractor for HMO council. I work as a builder and have past done full refurbishments of kitchens, bathrooms, demolishions and extensions. These include: installing and repairing pipes, drainage systems, bath, shower, sink, kitchen cabinets along with wall and floor tiling and laminate flooring. I collaborate with contractors and electricians in order to provide customers the best services. I have no reviews as I am new to this website. However, I am a highly driven builder with the ability to fix all types of problems. A hard working, enthusiastic and highly motivated individual with his own team that strives to achieve perfection in every job and task performed; with the proficiency to manage time efficiently, assess issues quickly and solving problems efficiently.
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Latest review:
Bathroom Fitting- 6 May 2024
100% recommend Laurențiu excellent quality of work and attention to the detail he done a very good job thank you.

3.9

Top rated Extension Builders

Our Extension Builders in Welwyn, are rated 3.9 out of 5 based on 15 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 Welwyn?

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 Welwyn 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 Welwyn who are available and interested can respond to your post.

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

What are the hourly rates of extension builders in Welwyn?

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

Find extension builders in Welwyn with MyBuilder

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

Step 2: Compare different extension builders in Welwyn

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

Step 3: Hire Welwyn extension builders with confidence

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

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

What to ask a Welwyn extension builder before hiring?

Before hiring an extension builder in Welwyn or extension building company in Welwyn, 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 Welwyn?

An extension builder in Welwyn 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 Welwyn 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 Welwyn?

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 Welwyn 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 Welwyn 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 Welwyn

Can an extension builder in Welwyn help with planning permission?

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

Many Welwyn 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 Welwyn help with materials and finishes?

Yes, most extension builders in Welwyn 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.