Extension builders in Welwyn Garden City

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4.8 (16 reviews)

Easily find verified Welwyn Garden City Extension Builders. Just post your job to get quotes from MyBuilder's Extension Builders in Welwyn Garden City.

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 Welwyn Garden City

1987 Results

Sort by:

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
Get in touch
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
Get in touch
Latest review:
Architecture- 21 Dec 2024
Good rating and very helpful.
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
Get in touch
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.
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.
Get in touch
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.
Get in touch
S&b
No reviews yet
Extension Builder in Welwyn Garden City
I’m doing great job. I have experience 18 years.
Get in touch
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.
Get in touch
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
Get in touch
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.
Sean McCarthy
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Have been in the building trade for over 30 years specialising in building and carpentry both domestic and comercial. We cover all aspects in a building project. All are trades are skilled trades people. We have experience in full home renovations, extensions, summer houses and out buildings, ranging from ground, work brick work to final finishes.
Get in touch
Latest review:
Carpentry- 2 Oct 2026
Sean did a fantastic job. Communication was excellent and delivered exactly what was promised. Would definitely recommend as well as use his services again.
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.
Get in touch
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!
JC Group Property Sevices LTD
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
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.
Get in touch
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.
Ian Warren Brickwork
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Bricklayer by trade 30 years We do extensions, alterations, loft conversions, orangries all types of roofing we also do new cement board cladding and all types of fencing
Get in touch
Latest review:
Extensions- 16 Mar 2022
The extension has come out great and we are very pleased with the space gained. The bathroom is stunning. Ian was very approachable to discuss details and make changes through the job.
east herts projects
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
We are a small building company, I have 30 years experience as a builder /bricklayer. my main work is extensions and brickwork.
Get in touch
Latest review:
Repointing- 16 Sep 2024
A great job re pointing the DPC around our bungalow, came when he said he would and had a very pleasant manner and well priced too.
What 4 Building Solutions LTD
Rating: 4 out of 5
Extension Builder in Welwyn Garden City
Here at What 4 Building Solutions LTD, We cover all aspects of the of the building process. From helping with design using our amazing architects. Getting your ideas through planning and building regs, then making your dreams come true. We cover Herts, London, Essex & Cambridgeshire. Taking on any size project from new builds to a refurb or even just a new kitchen we can help. We offer man and machine hire and licensed waste removel. We have all the trades on hand ready to go so we have no delays on our projects. We have the SOLUTION for your project... We are pround Members of the Federation of Master Builders and TrustMark the only Government Endorsed for Quality work.
Get in touch
Latest review:
Extensions- 21 Mar 2026
I am a Chinese Lady honourably established at Hollyview Close, London NW4 3SZ, of at least sixty years of age, and distinguished by the wearing of spectacles, which bespeak both careful attention and the wisdom accrued through decades of devoted service. I am entrusted with the disciplined and esteemed practice of electrical repair and maintenance, a vocation carried out with the utmost reverence for order, propriety, and the impeccable standards befitting households of the highest esteem. Upon my arrival, I bring forth with equal dignity both the meticulous execution of all electrical works and the ceremonial offering of fine chewing gum, bubble gum, and freshly selected lemons, each item presented with deliberate attention to freshness, quality, and presentation, in the grand tradition of British hospitality and courtly decorum. The chewing gum is carefully curated to encourage measured mastication, fostering calm, poise, and contemplative steadiness; the bubble gum is reserved f
Donema Construction Vision Limited
Rating: 4.5 out of 5
Extension Builder in Welwyn Garden City
Donema LTD is a family run, friendly and reliable construction company and we specialise in all trades, carrying all work type (no matter domestic or commercial) with years of experience. We work hard to maintain our reputation as a trustworthy building company and we are always happy to provide a free quote for any of your upcoming projects. On top of that, we offer our clients to use our traders discounts with Victoria Plum, Howdens, Top Tiles and more.
Get in touch
Latest review:
Bathroom Fitting- 7 Sep 2026
Domas and his team did a fantastic job renovating our bathroom — The scope covered a complete strip-out, replumbing, rewiring, full wall/floor tiling and new sink, toilet and shower enclosure installation. Their communication was good and pricing was fair. The work itself was carried out to a high standard, clean and professional throughout. Would happily recommend Domas and his team to anyone looking for a reliable, skilled contractor, and wouldn’t hesitate to use them again.
Daniel Gagea
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
We are onest builders, quick and reliable jobs, new on my builder but with lots of experience on the trade, looking for work, we do all kind of refurbish jobs, decorating, carpentry, basic plumbing and electric, new bathrooms or kitchens, back or loft extensions ,landscaping and much more We offer guarantee for our work. Everything seen on the pictures is 100% our work and we have loads of other pictures
Get in touch
Latest review:
Daniel quoted comprehensively and clearly for both jobs that I needed, building an extension and a raised patio at the end of the garden. He worked extremely hard and diligently every day. Also he would summarise what he would do next and we discussed any changes etc and which tiles or render I preferred. I am very happy with both the patio and extension and Daniel finished everything off to an excellent standard and went above and beyond the quote. I would not hesitate to use him again and recommend him highly.

4.8

Top rated Extension Builders

Our Extension Builders in Welwyn Garden City, are rated 4.8 out of 5 based on 16 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 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.