Extension builders in Welwyn Garden City

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4.6 (18 reviews)

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Some of our top rated extension builders in Welwyn Garden City

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RA Designs and Build Ltd
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
We are a dynamic construction firm specialising in innovative design and high-quality building solutions for both residential and commercial projects. With a commitment to excellence and attention to detail, our team of experienced architects, engineers, and skilled tradespeople collaborates closely with clients to bring their visions to life. We prioritise sustainable practices and utilise cutting-edge technology to enhance efficiency and ensure the durability of our structures. From initial design concepts to final construction, we are dedicated to delivering projects that not only meet but exceed client expectations, creating lasting value and aesthetic appeal. Our customers consistently recommend us for our commitment to quality, attention to detail, and exceptional customer service. They appreciate our ability to turn their visions into reality while staying on schedule and within budget. Positive testimonials highlight our professionalism, seamless communication, and the collaborative approach we take throughout each project. Clients feel confident entrusting us with their building needs, knowing that we prioritise their satisfaction and work tirelessly to ensure memorable and successful outcomes.
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Latest review:
Excellent quality of work which has not caused any problems for many years. Efficient work style whilst keeping up a high standard of work.
Annabaffer pierre
No reviews yet
Extension Builder in Welwyn Garden City
I am a head working individual no jobs to big or to small to handle from St Lucia love to play football
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LBS LANGTON LTD
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
WE ARE A BUILDING, GROUNDWORKS AND DEMOLITION SPECIALIST COMPANY WITH 28 YEARS IN THE INDUSTRY. WE PRIDE OURSELVES ON DOING THE JOB PROPERLY AND ON TIME WORKING WITH CLIENTS TO GET THE VERY BEST RESULTS
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Latest review:
Groundwork & Foundations- 25 Jul 2025
Ralph and his team did a fantastic job making a concrete base for a summer house He was reliable, charming and did a few extra jobs while he was here ! Ralph,Charlie, Roy and Captain were a pleasure to meet and we recommend this company wholeheartedly
Trevillion construction
No reviews yet
Extension Builder in Welwyn Garden City
My name is Nicky and I have over 15 years bricklaying and landscaping experience. With bricklaying I specialise in restoration and repointing. I am an experienced digger driver as well. Have worked on my own jobs which include garden renovations and extensions, and on bigger sites building new builds. I have recently set up this profile and look forward to new projects. Please feel free to get in contact for a quote or advice.
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First Choice KB Constructions Ltd
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
At First Choice KB Construction Ltd, we pride ourselves on being your go-to solution for home improvements projects. With a wide array of expertise in house extensions, refurbishments, loft conversions, and the renovation of bathroom and kitchens, we’re fully equipped to tackle diverse projects. Our services span across various aspects including brickwork, plumbing, electrical, and more, ensuring a comprehensive approach to every job. Our team boast over a decade of experience in the field, ensuring that we deliver results that stands the test if time. At First Choice, our goal is clear: to provide top-notch quality work that lasts, while adhering to agreed-upon timelines. We prioritize flexibility to accommodate our customers’ unique needs and preference. No project is too small for us. We're dedicated to delivering excellent service, ensuring that our clients' needs and requirements are not just met, but exceeded. Customer satisfaction is our ultimate priority.
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Latest review:
Extensions- 30 Jun 2024
Absolutely brilliant from start to finish. Customer service is A+ Very happy with the fitted wardrobes and work done.
JS Brickwork
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
We offer a professional and conscientious service where quality and customer satisfaction comes first. We undertake all masonry projects that include brickwork, blockwork, extensions, garden/boundary walls and house building. We also have expertise in carrying out restoration and refurbishment of listed and English Heritage buildings including specialist pointing such as weather struck and lime mortar applications, use of reclaimed bricks, arch work and stonework.
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Latest review:
Extensions- 2 Nov 2018
Building a 2 storey rear extension and hired Jamal to do the Block work. Initial ground storey heavy Hollow block walls for the 3 x 3m extension completed in only 3.5 days by Jamal himself with no extra help. Hardworking young guy. I was nearly bedbound with sciatica and in great pain and he immediately offered to source and buy on my behalf extra blocks required to relieve further stress on me. Very helpful, reasonable and understanding. Explained anything I asked him diligently. Knows his job and I will be calling him back when I have the money to complete the block work for the 2nd storey.
Proper Builders
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Proper builders! We are here to help your dreams come true. If you need home improvement, refurbishment, tiny repairs or even just an advice do not hesitate to contact us. We are a family company, professional and trustworthy. We always do our best to make our clients happy. Kitchen, bathroom, bedroom makeovers - that’s all we do every single day. We offer great service in competitive prices, innovative solutions and advices on every stage of the project.
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Latest review:
Powell is very thorough and I wouldnrate hus work very highly. He took his time and I am so pleased I cant thank him enough he has a great team and they work meticulous. Price was ok as well . He was flexible and felt heard. I would definitely book again . I just want to say a big thank u for a job well donem
D&S Construction
No reviews yet
Extension Builder in Welwyn Garden City
We provide construction services from planning to competition. We specialise in new builds, renovations or fit outs! Flooring and conversions (lofts) or extensions! We also offer other services which cover any construction builds like new kitchen strip outs or installing a new bathroom STP.
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Alexandru
New on MyBuilder
Extension Builder in Welwyn Garden City
I am a skilled and reliable carpenter and building professional with extensive experience in residential construction, renovations and home improvements across London. I specialise in first and second fix carpentry, loft conversions, house extensions, roofing, kitchen installations, bathroom renovations, flooring, doors, bespoke joinery and complete property refurbishments. I take pride in delivering high-quality workmanship, paying close attention to detail and treating every property with care and respect. From small home improvements to larger renovation projects, my aim is to provide practical solutions, honest advice, clear communication and a professional finish. Customer satisfaction is my priority, and I am committed to completing every project to a high standard.
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New Life Building and Maintenance Ltd
No reviews yet
Extension Builder in Welwyn Garden City
We are a construction company operating from 2018 but have been working in the construction industry for 20 years with a lot of experience in our portfolio. We can cover projects from new build, extentions, loft conversions, full refurbishment, drainage, patios, gardening ect. We would be happy to help with any of your needs for improving your home.
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RM ArtDeco LTD
No reviews yet
Extension Builder in Welwyn Garden City
RM Artdeco is a reliable and highly professional building company with a strong reputation across London and the surrounding areas. Most of our work comes through repeat customers and client recommendations, which reflects the quality, honesty and care we put into every project. We specialise in extensions, refurbishments, loft conversions, painting & decorating, patios, brickwork, insulation, carpentry, tiling, roofing, and all general building work. No matter the size of the job, we deliver clean, tidy and friendly service with excellent communication throughout. Our aim is simple: ✔ Provide high-quality workmanship ✔ Finish on time and within budget ✔ Make the building process smooth and stress-free for the customer We take pride in our work, treat every home with respect, and always ensure our clients are 100% satisfied before we leave.
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RQ Brickwork
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
bricklayer, undertake new builds, extensions ,garden walls stone work and repointing
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Latest review:
Bricklaying- 21 Jul 2025
Really nice guy to deal with. Job was done on time, looks good. I will definitely work with him again and would recommend.
Fatmir kraja
No reviews yet
Extension Builder in Welwyn Garden City
We are doing bricklaying for almost 25 years. Working all over the London doing extension and building houses from scratch to top.
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UK Development
No reviews yet
Extension Builder in Welwyn Garden City
House extensions & conversions Building alterations & refurbishment Loft & garage conversions Block work brick work and plastering Plumbing & electrical Joinery Roofing & flat roofs No job too big or too small
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Dad T and B son
No reviews yet
Extension Builder in Welwyn Garden City
Hard-working, get the job done very clean and very polite
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synergic design studio
No reviews yet
Extension Builder in Welwyn Garden City
My name is Sanjay Venkatakrishnan and I am an Architectural Assistant (Part 2) with a Master's degree in Architecture (RIBA Part 2) from the University of East London. I have extensive experience working with various architectural software such as Rhinoceros 3D, Autodesk AutoCAD, Autodesk Revit, Lumion, V-Ray, Enscape, and Adobe Creative Suite.
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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 18 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.