Extension Builders in Welwyn Garden City

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 3.8 (14 reviews)

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Some of our top rated extension builders in Welwyn Garden City

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D & F Brickwork
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Brickwork and All ground work,driveway,patio etc...
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Latest review:
Driveways (Paved & Loose)- 20 Dec 2025
Fatos arrived on time and completed the drainage repair efficiently, replacing it with paving bricks and cementing everything off smoothly and neatly. Very professional workmanship and a genuinely nice guy to deal with. Highly recommended.
Humphrys Maintenance Services Ltd
Rating: 4.5 out of 5
Extension Builder in Welwyn Garden City
Family run building & construction company specialising in extensions, refurbishments and specialist DDA adaptations works. We cover all works trades and will provide an excellent finish to your project. We also carry out hard and soft landscaping!
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Latest review:
Extensions- 21 Aug 2020
Cannot fault the twins they have catered so much for me and my family. They've accomadated all my changes throughout and advised throughout the whole process....4 to 6 weeks to completion...but what an amazing bunch of guys to come across... Cant fault them one bit.... You'll be proud to gave this team do any work for you.... One happy family...x
Ervis
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
We take on all kind of work that you need to do. We have been doing this for almost 8 years. We even do foundations digging muck away etc. Please do contact us for any further information we more then happy to answer.
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Latest review:
Handyman- 22 Dec 2025
Was very quick to respond and complete this job 3 hours later. To a high standard.
BARNETTS BESPOKE
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
At Barnetts-bespoke we specialise in high quality custom carpentry and building solutions tailored to your unique needs, proudly serving all areas of Hertfordshire and London we offer high end craftsmanship for a wide range of projects including bespoke wardrobes, kitchens, bespoke storage solutions, and complete renovations Our complete list of services are listed below *kitchens *bathrooms *extensions * bespoke wardrobes/cabinetry *roofing *flooring * summerhouses * Returbishments * new build
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Latest review:
Carpentry- 11 May 2020
Charlie was absolutely brilliant, fist class tradesmen with extremely high standards Will definitely use and recomend to others
JDL Construction
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
JDL Construction Limited are a Hertfordshire based building company offering both domestic and commercial services. We specialise in all aspects of construction including Home Extensions, New Builds, Garage Conversions as well as specialist Brickwork Contractors. Our company is fully insured and our tradesman are all fully qualified. JDL are members of many trade associations including Constructionline, CHAS, Federation of Master Builders and Federation of Small Businesses.
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Latest review:
The project was to construct a 15m2 extension to our rear lounge on the ground floor plus a 4m2 extension to the bathroom on the first floor. This involved foundations, walls and roof tiling in addition to the installation of a 5m long RSJ to support the first floor bedroom. Jamie was selected because of his recent training and apparent enthusiasm. He planned and carried out the work very well. Problems when encountered were discussed and resolved with professionalism and enthusiasm. The resulting work has been completed to a high standard and I am well satisfied with the result. The time taken was as planned, he worked on a daily rate which was to my budget. Jamie' strengths are a good basic knowledge of the building regulations, good communication skills with other workers, suppliers and inspectors and excellent basic brick laying skills with a eye for dimensional regularity and excellent final appearance. I would strongly recommend this young and enthusiastic tradesman for any similar project work involving use of his excellent bricklaying skills.
AU Construct
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Groundworks and multi-trader with strong experience in domestic extensions and general building works. I am also a chartered surveyor, with over 10 years experience. I take pride in delivering reliable, tidy workmanship from groundwork through to completion of extensions and internal works, with clear communication and a straightforward approach to pricing and delivery.
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Latest review:
Amazing job! Tiling has completely transformed our kitchen, thank you Ali
R V Buttner Building Services
No reviews yet
Extension Builder in Welwyn Garden City
I have 45 years experience in the building trade from being a site carpenter to a foreman to site manager to become a builder in the domestic market I have a five star rating through a company called rated people numbering 35 five star ratings I’m experienced and reliable and I am a good communicator
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My Craft Building Solutions Ltd
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
My Craft Building Solutions Limited are a family run business, and we offer all aspects of building services. No job too big or too small with a lot of our work done for Anglian home improvements we understand the importance of customer care We specialise in: Extensions Conversions Porches Bricklaying
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Latest review:
Groundwork & Foundations- 27 Sep 2023
A team of 3 bothers, nice guys and did a good job. maybe a little over priced but I did agree the price before, so really I cannot complain.
NOVATE ACS LTD
Rating: 3 out of 5
Extension Builder in Welwyn Garden City
NOVATE ACS LTD, you can see more detail on our services on our website. We are an innovative design led London based Chartered RIBA Architectural Practice and an Accredited Construction Company. We specialise in home extensions, loft conversions, refurbishments and new builds
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Latest review:
Architecture- 21 Dec 2024
Good rating and very helpful.
T.G & Sons Construction Ltd
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
I have worked in Construction since 1990. I have owned and run my own Business since 1998. We undertake projects from £1k to £2M. New Builds, renovations, Extensions, Loft Conversions, Conservatories, Outbuildings, full Refurbishments and Modernisations. We have all trades available and take on every aspect of the building trade. We also provide Architectural and Maintenance services. We Plan, Design, Build & Maintain.
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Latest review:
Restoration & Refurbishment- 6 Aug 2019
We are so pleased with the result. All the guys were friendly, helpful and hard working. They did exactly what they said and kept us fully informed. We should have done this years ago. I fully recommend them. A great bunch.
Mc Donald Ltd
No reviews yet
Extension Builder in Welwyn Garden City
Mc Donald offer a wide range of services that cover the entire project. From concept to completion. Our wide range of capabilities means you’ll always have our in-depth expertise, experience and know-how at your disposal. By providing every service under one roof, Mc Donald Ltd can handle your entire project from start to finish. This includes architectural planning, designing, building regulations and planning permission, structural engineering, constructing and managing your project.
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HARMONY BUILD LTD
Rating: 4.8 out of 5
Extension Builder in Welwyn Garden City
We are a fully insured company of dedicated and experienced construction workers specializing in: - Complete property refurbishments - Extensions - Loft conversions - Bathroom and kitchen refurbishment - Tiling, flooring, and decoration works With over 15+ years of experience, our expertise is suitable for any client, no matter how complex or unpredictable the construction project may be. Experience peace of mind as we go above and beyond to deliver exceptional results every time.
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Latest review:
Restoration & Refurbishment- 9 Apr 2026
Greg and Bart carried out an extensive internal renovation for us in 2023 and I can only apologise for the delay in leaving this review, however I can do so now with the benefit of nearly three years using the spaces. The work included some plastering, full decoration of three rooms, new skirtings, architraves, herringbone flooring throughout and building alcove shelves and cupboards. The team were a pleasure to work with throughout and were honest about where compromises would need to be made with e.g. undulating Victorian floors. They came up with solutions and the end result was of very good quality. Highly recommended.
T De Maio Brickwork services
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
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.
Pat Mcgeough
Rating: 4.9 out of 5
Extension Builder in Welwyn Garden City
McGeough & Sons Ltd is a family run business based in Bedfordshire. I am a time served carpenter with 27 years extensive experience in all aspects of refurbishments and building. Fully insured, contact us for a non obligated quote or advice
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Latest review:
Conversions - General- 4 Jan 2026
Pat was a pleasure to deal with from beginning to end he had everything covered and made the whole project a seamless experience. He provided me with a professional quote and had the patience to deal with my questions. He started the project on time svd no thing was too much trouble, when I needed a roofer to fix some issues with a leak he had someone on the job within a day. He handled every aspect of my garage conversion effortlessly and had the job finished on time right before Xmas. Would 100% use Pat again. Great guy who also knows good trades people. Thanks Pat.
Milestone Brickwork
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Local bricklayer based in herts and Essex, we also undertake patios and fences.
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Latest review:
Jack came and quoted to lay a new patio and a shed base. He listened to exactly what I wanted (something other workmen didn’t do!) and came back with a very reasonable quote and said he would complete the job on a weekend as I wanted it done asap. From start to finish Jack was really polite and friendly and worked really hard to get the job finished - so much so, I’m adding more bits to the garden and will get Jack back over to do it!
AMT Property Solutions
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
I have spent 40 years in the construction industry, starting straight from school where I completed a five-year apprenticeship in the glass and glazing industry. Over the years, I progressed through all areas of the window and fenestration sector, gaining extensive hands-on experience in all types of glazing, window systems, fire doors, conservatories, and associated installation works. As my career developed, I broadened my expertise further by moving into carpentry and developing practical skills in a range of additional trades, including brickwork, tiling, kitchen fitting, and general building works, to name a few. This diverse background allows me to offer a well-rounded understanding of both specialist and general construction projects. We operate throughout Bedfordshire, Hertfordshire, Northamptonshire, and Oxfordshire, including all surrounding areas.
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Latest review:
Decking- 25 May 2026
All as planned

3.8

Top rated Extension Builders

Our Extension Builders in Welwyn Garden City, are rated 3.8 out of 5 based on 14 reviews from customers like you.

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What types of services are offered by local extension builders in Welwyn Garden City?

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 Garden City 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 Garden City who are available and interested can respond to your post.

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

What are the hourly rates of extension builders in Welwyn Garden City?

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

Find extension builders in Welwyn Garden City with MyBuilder

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

Step 2: Compare different extension builders in Welwyn Garden City

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

Step 3: Hire Welwyn Garden City extension builders with confidence

After gathering all the information and quotes from your chosen home extension builders in Welwyn Garden City, 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 Garden City extension builders are ready to help. Use MyBuilder today to find the right professional for your home extension.

What to ask a Welwyn Garden City extension builder before hiring?

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

An extension builder in Welwyn Garden City 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 Garden City 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 Garden City?

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 Garden City 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 Garden City 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 Garden City

Can an extension builder in Welwyn Garden City help with planning permission?

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

Many Welwyn Garden City 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 Garden City help with materials and finishes?

Yes, most extension builders in Welwyn Garden City 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.