Extension builders in Welwyn Garden City

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4.6 (17 reviews)

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Some of our top rated extension builders in Welwyn Garden City

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jc_electrical
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
We are a construction company with years of experience in all aspects ranging from groundwork, carpentry, extensions and many more. We pride ourselves on delivering a high quality finish.
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Latest review:
Landscaping- 20 May 2026
Very pleased. Responsive and did a good job
NDBates Bricklayer/ Plasterer/ General Builder
Rating: 4.7 out of 5
Extension Builder in Welwyn Garden City
Have 24year of experience in building trade coming from a family run firm with over 80 years of experience working on extensions refurbishments newbuilds and Landsapcing and all General building I have a nvq level 2 in brickwork and enjoy working in the building trade I do my up most to work with the customer to bring there projects to life and with competitive Also, We work with our clients
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Latest review:
Extensions- 3 Nov 2024
Job significantly escalated as more and more issues were discovered to be inherently wrong with the house, added to which the architect was unfortunately taken seriously ill at the start of the project. Nathan managed everything, coordinated trades, resolved issues as they arose and delivered a virtually new house with all floors, roof and walls replaced, eaves replaced, full drainage replaced, Excellent work, extremely friendly, highly recommended
Parve constructions ltd
No reviews yet
Extension Builder in Welwyn Garden City
I am hardworker and honest I am doing everything in building work plZ give me chance for good work
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Grand Developers Limited
No reviews yet
Extension Builder in Welwyn Garden City
With 8 Years of experience in the electrical industry, I bring a wealth of expertise and a passion for excellence to every project I undertake. From New installation to part rewires to fault finding, I have honed my skills to deliver top-notch results, consistently exceeding client expectations. I've been dedicated to the electrical and building trade for over 8 years, during which I've refined my craft and adapted to the ever-evolving demands of the industry. This tenure has equipped me with the knowledge and proficiency needed to handle a diverse range of projects with precision and efficiency. Based in Hayes Middlesex, I offer my services across London and the Berkshire area. I'm readily available to bring your vision to life. As an electrician, I possess exceptional fault finding skills, allowing me to quickly identify and resolve electrical issues. Whether it's a faulty wiring system, malfunctioning appliance, or power outage, I have the expertise to pinpoint the root cause of the problem and implement effective solutions with precision. I also offer custom design and installation services: I offer personalised design and installation services tailored to meet the unique needs and preferences of each client.
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Huseco Limited
Rating: 3.7 out of 5
Extension Builder in Welwyn Garden City
HUSECO Limited is a well-established family business specialising in domestic renovation and construction projects. Our portfolio of skills also includes architectural design, interior design, and planning, which allows for stylish renovations, extensions, lofts, and modern living spaces. We have a loyal team of highly skilled builders, and the dedicated project manager personally oversees all our projects
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Latest review:
Extensions- 14 Sep 2025
How long should a 3m extension take if drawings were approved in April, the conservatory was demolished, the foundation completed, and the steel structure was already on site by May.?
SM Tech Ltd
No reviews yet
Extension Builder in Welwyn Garden City
Home Improvement Experts | At SM Tech LTD, we specialise in transforming homes with expert renovation services that enhance both beauty and functionality. Our skilled team is committed to delivering high-quality, cost-effective solutions tailored to your needs. Whether it’s a kitchen makeover, a full home remodel, or small home improvements, we bring your vision to life with precision and care. Trust us to make your home renovation experience smooth, reliable, and rewarding. Let’s create the space you’ve always dreamed of!
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Mayor Brickwork Ltd
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
We are a professional construction company with over 10 years of experience specialising in new builds, extensions, loft conversions, brickwork, and structural shell works. We provide high-quality workmanship for both residential and commercial projects, delivering reliable labour and material packages tailored to our clients’ needs. Our team is skilled, hardworking, and committed to completing projects to a high standard while working within deadlines and maintaining a clean and safe working environment. We also work in line with NHBC standards and hold business insurance for peace of mind. Our services include: New Builds Extensions Loft Conversions Brickwork & Blockwork Retaining Walls Stonework Repointing Roofing & Structural Works Residential and commercial projects General Maintenance We pride ourselves on professionalism, attention to detail, and building long-term relationships with our clients through trust and quality results.
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Latest review:
Repointing- 20 Nov 2025
Everything went great, the brickwork was replaced and painted so it looks the same as the rest.
Tyne Homes (GH Inc Ltd)
No reviews yet
Extension Builder in Welwyn Garden City
We offer professional and certified construction services with the best team of professionals and more than 10 years of experience in building and renovation. Call us today for a free quote and get a special discount for your first works with our company.
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Project A Construction Limited
No reviews yet
Extension Builder in Welwyn Garden City
Project A covers all aspects of groundwork, extensions, driveways, refurbishments and tiling. Our work is build with experience and reliability.
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IVD Construction Ltd
No reviews yet
Extension Builder in Welwyn Garden City
Hello, I’ve been in the construction business for more than 13 years. I’ve been doing high end projects including basement excavation works, new roofs, extensions, full internal renovations, plumbing and electrical works, etc. My company works with high skilled professionals to satisfy all customer needs.
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Justas Kusak
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
I'm a self employed roofer for more than 14 years now. Roofing specialist you can rely on. 10 year Warranty for work. EPDM, GRP, Felt, RESITRIX, Kemperol, lead, slates, tiles, skylights and more...
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Latest review:
Fascias & Soffits- 19 Aug 2019
Very happy with the work Justas did, house looks much tidier with the new fascias and guttering. He arrived on time, quoted a fair price and did a good job. I would happily recommend and hire him again.
D.Smith Contracting
Rating: 4.8 out of 5
Extension Builder in Welwyn Garden City
Sole trader with 8 years experience. Drainage, civils and groundworks, strip outs, all undertaken to high standards. Drainage services include, off mains installations such as septic tanks and sewage treatment plants, CCTV surveys and reporting, repair works such as dig ups and non invasive patch repairs. Civils such as ducting work, draw pits. Then groundworks such as footings, foundations, concrete slabs, soak aways, artificial grass, patios, grading and site prep. Building strip out services. Tickets and qualifications, SMSTS(site manager), SSSTS(site supervisor), first aid, NPORS digger under and above 10t, NPORS dumper, IPAF, confined space, and high pressure water jetting. Public liability up £1,000,000
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Latest review:
Groundwork & Foundations- 28 Oct 2026
Every once in a while you get lucky with a contractor and Dan is that contractor. Reliable, great communication and professional. He carried out some drainage work at the front of my property. Kept me informed every step of the way and was happy to answer any questions I had. Thanks very much, really happy with the outcome!
Boundary builders
No reviews yet
Extension Builder in Welwyn Garden City
Family run company specializing in making more space extensions, loft conversions, out buildings,new builds. we can take the stress out of building for you from the start to finish with setting out architecture drawings building control structure build and interior ..
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D&DGeneral Building Construction
No reviews yet
Extension Builder in Welwyn Garden City
D&D General Building Construction with more than 22 years experience in a Construction sector as commercial and private property , ( Registered with Federation of Master Builders & UK Degree Civil Engineering ) is committed to excellence in every aspect of our operations. From the initial consultation to the final walkthrough, we ensure that every project reflects our dedication to our clients’ satisfaction, environmental responsibility, and the highest standards of quality. Join us as we continue to build a better future, one project at a time.
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Arcus Construction Ltd
No reviews yet
Extension Builder in Welwyn Garden City
Arcus Construction was formed with the view to deliver the highest quality standards alongside exceptional customer service, making the construction process simple, seamless, well managed and entirely positive for our clients. As refurbishment & construction specialists, our multi-skilled team covers all trades, enabling us to provide a complete in-house, end-to-end service, which is managed & completed to our own impeccably high standards
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Viranna Professional Building and Cleaning Service Ltd
Rating: 4.4 out of 5
Extension Builder in Welwyn Garden City
Viranna Brickwork Contractors are actively looking to take on more work and would like to be in your tender list. We are based in Surrey, South Croydon, but travel and work all over the South East. We have over 10 years’ experience in the Building industry and taking pride in the job. Looking forward to work with you on your next project. Viranna Professional Building and Cleaning Service LTD
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Latest review:
Bricklaying- 26 May 2020
Very professional and reliable. Quality of work is very high standard and will definitely use their services again. Come highly recommended.

4.6

Top rated Extension Builders

Our Extension Builders in Welwyn Garden City, are rated 4.6 out of 5 based on 17 reviews from customers like you.

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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.