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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Oprea ltd
No reviews yet
Extension Builder in Welwyn Garden City
Hello, my company declares punctuality, we do everything with proper documents, invoices
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Amritpal singh
Rating: 4.5 out of 5
Extension Builder in Welwyn Garden City
We are here to assist you and provide you the work you dreamt off on very reasonable prices so trust us with your house and we will do the best for you .please do understand that we have to pay to get contact details of customers so it’s important being a customer to check the portfolio before short listing a tradesman just to be sure that we won’t just be paying for nothing .
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Latest review:
Extensions- 4 Jan 2026
I hired Amrit based on positive reviews, but my experience was extremely poor. The work showed all the signs of a cowboy builder. I’m sharing this to help others avoid the stress, delays, and financial risk I went through. 1: No Respect for Contract or Deadlines Contract deadline was 15th September, which he completely missed. Despite delays, he demanded money almost daily. When I referred him to the payment and work schedule he signed, his response was: “I didn’t read it, I just signed it.” 2: Dangerous and Unprofessional Working Practices Brought in unqualified workers, many of whom could not speak basic English. He ignored safety standards throughout the project and wanted to use the same unqualified workers for gas work, which is extremely dangerous. When I objected, his response was: “Don’t worry, you will get a new house if it blows up as you have insurance.” 3: Work failed multiple building control inspections. He eventually refused to cooperate with the building inspector.
MUZAAL construction limited
No reviews yet
Extension Builder in Welwyn Garden City
A professional and friendly construction team and our aim is to keep our clients happy and satisfied.
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Sir groundwork ltd
No reviews yet
Extension Builder in Welwyn Garden City
All aspects of groundwork -driveway and patios paving&slabing -concrete foundations -fencing and turning -drainage/land drain -kerbs/edgings -block and beam -block work and brick work
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Bricklayer paving concrete kerbs
No reviews yet
Extension Builder in Welwyn Garden City
Professional Bricklayer based in London with 15+ years experience in construction, Fully qualified (CSCS Blue Card, NVQ Level 2). Experienced in managing small teams and delivering projects safely and efficiently. Services include:• Brickwork & Blockwork• Extensions & Structural Work• Garden Walls & Landscaping Brickwork• Repairs & Repointing I focus on quality, precision, and customer satisfaction. Clean and tidy work guaranteed. Available for private and subcontract work. Competitive prices and free quotations.
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The Business Plastering
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Welcome to Jay's Plastering Services, we say only the best will do for competitive prices. We specialise in Plastering but we are more than happy to take on most jobs such as extensions, kitchen fitting, carpentry, etc. We are very clean and tidy for what we do and we have never had a job go wrong.
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Latest review:
Plastering- 30 Oct 2015
Young James did a very good job. I would recommend him to anyone.
POLISH DECORATING SERVICES LTD
Rating: 4.9 out of 5
Extension Builder in Welwyn Garden City
We are not the cheapest but we are Master Builders experienced in all aspects of building works including bespoke services. Dedicated team of craftsmen always deliver jobs to the highest standards. We provide full certification for any gas or electrical works. City&Guilds- N.V.Q., P.A.S.M.A. and I.P.A.F. Over 15 years of experience in the UK.
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Latest review:
Extensions- 11 May 2018
After a rogue builder left me with 18 (eighteen) structural issues. Lez and his crew came in transformed my failed extension into a masterpiece. All aspects of the job was done to the highest quality and utmost care and attention to detail was shown to building control needs. They cleaned up after every day and made sure the house was habitable, as I had to live there. Every aspect of the build, from the carpentry, plastering and tiling was first class and their recommend electrician and plumbers were from the same stock. Total professionals. My only regret is that I did not use this builder the first time. The prices were reasonable and even building control had good word to say about their work. Thanks Lez
Peter The Builder
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Hello. My name is Peter. I am a builder based in Slough. I used to run my own business back in Poland for 10 years. I do all sorts of work like painting, decorating, tiling, flooring, kitchens, bathrooms, plastering, bricklaying, driveways, gardening, fencing, paving and patio slabs , turfing . I am respectful and keen to get the job done. Thank you so much for your time , Kind regards.
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Latest review:
Fencing- 9 Jun 2026
Recommended - competitive price and completed as agreed.
Triune Developers Ltd
No reviews yet
Extension Builder in Welwyn Garden City
Triune Developers Ltd is a professional property development and building services company known for delivering high-quality workmanship and reliable project management from start to finish. With over 15 years of experience, we specialise in transforming properties through skilled construction, refurbishment, and decorative services. Our dedicated painting and decorating division is at the core of what we do. We provide premium interior and exterior finishes with exceptional attention to detail—whether it’s a full property renovation, a commercial space upgrade, or a single-room refresh. Every project is completed with preparation, precision, and a flawless finish that lasts. Alongside our specialist painting services, we offer a full range of building and development solutions, including: Property renovations & refurbishments. Home extensions & structural improvements. Kitchen and bathroom installations. Carpentry and joinery services. General building maintenance and repairs. We pride ourselves on being efficient, professional, and easy to work with. Our team works cleanly, communicates clearly, and respects timelines and budgets. The result is a smooth, stress-free experience and a finish that elevates the space.
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ZadSaam Ltd
No reviews yet
Extension Builder in Welwyn Garden City
I’ve over 15 yrs experience in the industry with a team of expert tradesmen+workers in all aspects of bldg from painting+decorating to plumbing electrical carpentry kitchen+bathroom design to installation full refurbishment+extensions+conversions Friendly consultation, NO pressure/obligation/hassle
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Clarke's Design & Build Limited
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Flawless Finishes - look right here! Clarke's Design and Build are general contractors based in London, serving both the London and surrounding areas of the United Kingdom. Clarke's Design and Build focuses on tailor made home design, residential / commercial renovations and aim to use sustainable, environmentally friendly resources. We specialise in design, extensions, interior/exterior upgrades and aspire to turn challenges into solutions, plans into useful creative spaces.
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Latest review:
Carpentry- 22 May 2024
Great work from Leslie! On time, friendly, accommodating of all my questions and paid attention to all the details. Thank you Leslie.
D H Builders & Contractors LTD
No reviews yet
Extension Builder in Welwyn Garden City
New build Loft Roof K rend Electric Plumbing Extension Drive Decorating Bath
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Lovedeep gill
New on MyBuilder
Extension Builder in Welwyn Garden City
good jobs my hand and my team happy client
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Kegel LTD
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Kegel Group is an experienced construction contractor with over 15 years of experience across residential and large-scale construction projects in the UK. Our team covers a wide range of building works, from smaller refurbishments and repairs to complete house renovations, extensions and new-build projects. We specialise in brickwork and blockwork, foundations, drainage, roofing, SFS, façades and cladding, GRC, stonework, repointing and external works. We can also provide experienced carpenters, electricians and plumbers when required, allowing us to manage complete projects from start to finish. Our team has extensive experience working on major construction developments, where quality, safety, programme and attention to detail are essential. We are flexible in size and can provide a small team for private residential works or increase our workforce for larger projects and tight programmes. At Kegel Group, our focus is simple: quality workmanship, reliable delivery and getting the job completed properly and on time.
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Latest review:
Bricklaying- 19 Nov 2019
Alex is a polite professional who knows his job. He did a good job for me. I can recommend him.
LOLLI DESIGN
No reviews yet
Extension Builder in Welwyn Garden City
With years of hands-on experience in plastering, skimming, insulation, drywall installation, and general building works, we take pride in turning your vision into reality. We work closely with homeowners, architects, and design studios to ensure every project is completed on time, on budget, and to the highest standards
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Marius Ciocarlan
No reviews yet
Extension Builder in Welwyn Garden City
I neew in the area , I lock for job with interest and with very professional skills
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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.

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.