Extension Builders in Welwyn

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 3.7 (13 reviews)

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Some of our top rated extension builders in Welwyn

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T & D Barrs Plumbing and Heating Ltd
New on MyBuilder
Extension Builder in Welwyn
We provide a reliable, efficient service; on time and to budget, keeping large and small business operations running efficiently and safely. From routine repairs and maintenance through to complete project management. Our Services cover: • Central Heating & Plumbing • Electrical • Building Services & Project Management • Carpentry Works • Gas We are a family business, independent of any other organisation, established in 1997. We are an environmentally aware company and are proud to have achieved ISO14001. Be reassured: with T&D Barrs you’ll receive unbiased advice, a fair price and quality workmanship consistently.
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SureBuild Homes
No reviews yet
Extension Builder in Welwyn
SureBuild Homes specialise in new builds, extensions, renovations, kitchen and bathroom refurbishments, landscaping, loft & garage conversions, carpentry, driveways & patios and fencing. You can have total peace of mind knowing that we are fully insured and guarantee quality. We are members of the Federation of Master Builders (FMB). We cover Hertfordshire, London, Bedfordshire, Buckinghamshire and Middlesex.
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Miron
Rating: 5 out of 5
Extension Builder in Welwyn
General billing Painting, loft conversion, extension, handyman
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Latest review:
Handyman- 15 Sep 2021
He was very well manned and professional and did a little work more work without charging extra. He is very tidy and the price was very reasonable. I will certainly hire him again in the future . Thx Miron xxx
Danga
New on MyBuilder
Extension Builder in Welwyn
Professional tiler with experience in wall and floor tiling, bathrooms, kitchens, and renovations. I take pride in delivering high-quality workmanship, attention to detail, and reliable service. Customer satisfaction is my priority on every jo
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Brilliant Property Services
No reviews yet
Extension Builder in Welwyn
We are a small local team of property and garden tradesmen who have many years experience working with customers providing a full property service. From driveways, patios and gardens on the outside to garage conversions, kitchens and bathroom refurbishments on the inside. We have enjoyed working with most of our customers for many years helping them to transform their properties and gardens into Brilliant spaces.
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THE OREILLY GROUP LTD
Rating: 5 out of 5
Extension Builder in Welwyn
We undertake all Groundworks packages to simple repairs to large site packages.Having been in the industry almost 20 I have worked on a number of large scale projects including RAF Northolt,Harry Potter world London and many housing developments. All our lads are fully trained and certified,including Cscs,Cpcs,first aid etc.We own all our own plant from 1 tonne to 30 tonne excavators, dumpers, skips and grab lorrys.Here at The OReilly Group we pride ourselves on repeat business & recommendations
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Latest review:
Groundwork & Foundations- 25 Jul 2023
The Oreilly Group completed my groundworks, external drainage and some knock throughs on my extension. The job commenced when promised and was completed within programme. The works were completed on time and this included some extras I threw in along the way. I would reccomend Owens team for any groundwork and drainage project - very happy with the outcome.
MNM CONSTRUCT LTD
Rating: 5 out of 5
Extension Builder in Welwyn
The company was set up following years of working on small and large projects for both private and public clients subsequently understanding the continuous increase in demand of manageable, cost effective and quality projects.
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Latest review:
Plastering- 26 Jun 2016
We hired Manu and his team to plaster our summerhouse, relocate two radiators and fit a new bulkhead ceiling in the lounge and install LED tape. He was knowledgable, professional and considerate and I highly recommend Manu and his team. Not only did he understand the project for the bulkhead, but he came up with another suggestion which we went with, and friends and family agree looks amazing. The finish on the plasterwork is perfect and Manu and his team worked hard and even left the summerhouse cleaner than when they started! It is great to work with a team who pay such attention to detail, listen to the client and get the job done to a high standard. It was a risk to go with Manu as he didn't have any feedback when I hired him. I actually got him to quote so I could compare prices with someone else I had in mind to do the job, but when I met Manu I felt he would be the better person to do the job as he listened and understood exactly what I wanted and so I ended up hiring him instead. I wouldn't hesitate to hire him for any future jobs. Thank you Manu and team!
BCH 3 Projects Ltd
No reviews yet
Extension Builder in Welwyn
Hello . I'm Barry from BCH3 Projects Ltd. We have worked on many prestigious projects in London but we are now looking to give more local customers a great service from free advice to full house renovations . Please do not hesitate to give me a call. We are an all trades company. Specialising in Carpentry and Joinery .Thanks for taking time to read my introduction.
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Gudgeon’S groundworks and construction
No reviews yet
Extension Builder in Welwyn
Gudgeons Groundworks & Construction is a Hertfordshire-based contractor specialising in residential extensions, new builds, and structural groundworks. We deliver high-quality construction from foundations and drainage through to superstructure, working closely with clients, architects, and engineers to ensure every project is completed to specification and the highest standards. From single-storey and multi-storey extensions to full new-build homes and outbuildings, we provide a reliable, end-to-end service built on craftsmanship, attention to detail, and clear communication.
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Mapna constraction ltd.
Rating: 4.2 out of 5
Extension Builder in Welwyn
Hi everyone, We are a family-run business with over 10 years experience and pride ourselves on our incredibly high-standard quality of work, customer rapport, competitive prices and efficient time-frames. With our customers' satisfaction held in the heart of our work, we will go the extra mile to ensure all needs and requirements are met and you are 100% satisfied with the end product. 'If it isn't good enough for our home, then it isn't good enough for yours'.
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Latest review:
Bathroom Fitting- 8 Apr 2026
Arash and the team were great - on the job on time every day - flexible in regards a lot of the fittings and adjustments. Very good price and work completed on time. Monies all agreed upfront, payment in part as based on progress. Will use again.
Newstar Building Services Ltd
Rating: 4.9 out of 5
Extension Builder in Welwyn
HI my name is Bill and I run a building company. All our work is base on recommendations costumers We work all around London.
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Latest review:
Hard Flooring- 22 Oct 2025
Enea did an incredible job, and we’re beyond happy with the final result. He was very accommodating, helped us choose the right tone of varnish beforehand, and kept us updated throughout the day by sending pictures of his progress (as we were both at work). Enea is trustworthy, and even though we didn’t have the chance to meet him in person, he left the flat securely, taking care of our keys and door. We highly recommend Enea!
Elezi plastering
No reviews yet
Extension Builder in Welwyn
Skimming Over skimming Wet plastering Drylining Restoration works Plaster boarding Materials Supply & installation Water damage repairs Sand and cement renders Rough cast renders Modern silicon based renders External wall insulated renders Rendering & K-Rend Pebble Dash Materials Supply & installation
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Marra Constructions
No reviews yet
Extension Builder in Welwyn
Marra Construction brings over a decade of hands-on experience to every project, delivering excellence across a wide service area with a commitment to quality and structural integrity. We specialize in the critical first stages of any build, providing expert groundwork and foundation services that ensure your project starts on a solid base. Beyond the earthworks, our team is highly skilled in executing full-scale new home builds, seamless property extensions, and high-quality loft conversions designed to maximize your living space. We pride ourselves on a work philosophy centered on reliability, precision, and transparent communication, making us the trusted choice for homeowners looking for a dedicated partner to bring their architectural visions to life.
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Digswell Services
Rating: 4.6 out of 5
Extension Builder in Welwyn
We are a local company focused on delivering a first class finish alongside a first class customer experience. You and your project are at the heart of everything we do. We offer General Landscaping, Air conditioning, Electrical, Decorating and much more
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Latest review:
Handyman- 29 Jul 2024
Robert gave a quote and came around to double check. We agreed a date, and later I re-confirmed about a week before, but he did not turn up on the day. I have not heard anything from him in over a couple of weeks despite a number of attempts to make contact, so I just presume he was not able to do the job. Disappointed at lack of communication and needless delay.
K B brickwork
No reviews yet
Extension Builder in Welwyn
20 years experience
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Magna Build
No reviews yet
Extension Builder in Welwyn
Specialise in carpentry work. As well as extensions and new builds - Erect stud walls - Kitchens - Hanging doors - Flat and pitched roofs - Skirting & Architrave - Flooring - Joists - Shelves - Cupboards - Stairs - Cladding
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3.7

Top rated Extension Builders

Our Extension Builders in Welwyn, are rated 3.7 out of 5 based on 13 reviews from customers like you.

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

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 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 who are available and interested can respond to your post.

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

What are the hourly rates of extension builders in Welwyn?

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

Find extension builders in Welwyn with MyBuilder

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

Step 2: Compare different extension builders in Welwyn

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

Step 3: Hire Welwyn extension builders with confidence

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

What to ask a Welwyn extension builder before hiring?

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

An extension builder in Welwyn 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 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?

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 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 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

Can an extension builder in Welwyn help with planning permission?

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

Many Welwyn 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 help with materials and finishes?

Yes, most extension builders in Welwyn 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.