Extension builders in Welwyn Garden City

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

1988 Results

Sort by:

Matteo construction Ltd
No reviews yet
Extension Builder in Welwyn Garden City
Hi there hope you’re all keeping well I would like to introduce myself and my company Matteoconstruction Ltd I kindly ask if you could take a moment and visit our website site and see the service that we offer Please share with me if there is anything that we can assist you in the future with your work loads Kind regards Flo At Matteoconstruction Ltd
Get in touch
Home Renovations Ltd
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
We're a building company specializing in house extensions, loft conversions and refurbishments. Our clients come from New Malden, where we're based, but also surrounding areas. The vast industry experience enables us to provide valuable advice, professional services and individual approach, benefiting our customers. As we understand trust and credibility are crucial when undertaking such projects, we arrange viewings and provide customers with references and photos of our most recent projects.
Get in touch
Latest review:
Extensions- 24 Jun 2017
We had a large piece of work done by Johan and his team. It was a 4m single storey rear extension with new kitchen installation, converting the old kitchen into a downstairs bathroom and utility room, plus other bits and bobs like new boiler, rear patio. We got quotes from a few builders, Home Renovations weren't the cheapest, they were actually towards the higher end. But we went and saw their previous work and spoke to some of their other clients. The work was done to a high quality and the clients seemed to be happy so we decided to go with them. Johan's team are very hard working, professional and polite. Pawel and his team of builders, bricklayers, plumbers, electricians, etc. would turn up before 8am and finish at 6pm working solidly throughout the day. There is Magda as the project manager who keeps you in the loop, and answers any of your questions (which we had many). There is Michaela on the finance side who keeps you up to date with the budget. Our budget went over by 5% with "variations" (extra work or materials) but it was always communicated why and the work wasn't done without our approval. Pawel would give his recommendations but the final word would always be ours. But these things can add up. Overall we were very happy with the build, it was done to a very high standard. They also finished it before time. They said it would take 12 weeks in fact they finished it in 10 weeks which was amazing as you would normally expect these things to go over.
A.S.L Corporation LTD
No reviews yet
Extension Builder in Welwyn Garden City
A.S.L Corporation Ltd, stands as a powerhouse in the UK construction industry. Based in London but serving the entire nation, we operate under a singular, driving philosophy: "Built Strong. Built Right." Our brand is defined by a commitment to civil-engineered results that prioritize structural integrity and aesthetic precision. We bridge the gap between high-end quality and affordability, offering a Best Price Guarantee that ensures our clients receive premium construction without the premium price tag. Our "no shortcuts" approach is backed by a dedication to on-time delivery; we respect your schedule by starting promptly and finishing according to plan. Our versatile service portfolio covers every stage of property development. We handle heavy structural work, including extensions, lofts, and garage builds, alongside refined interior services like bespoke kitchen fitting and tiling. Our expertise extends to the exterior with professional roofing, painting, and civil works. To ensure long-term value, our maintenance and "Deep Finish" teams provide specialized care, from gutter restoration and roof cleaning to driveway jet washing and protective sealing. At Beast Construction, we transfor
Get in touch
AJ Partners Ltd
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
We are family business working in different levels of building industry. Refurbishment, supply and fit and installation service. Carpenter, Joinery, Tiling, Plumbing, etc. Supply or supply and fit, refurbish and new build We completed various projects in London and surrounding areas We listen to our clients needs and liaise with you throughout your project to ensure that the project finishes on time and on budget. Trades 15 Years of experience and good reviews leads our work.
Get in touch
Latest review:
Kitchen Fitting- 7 Jun 2020
We liked Alex from the first meeting and the first impression was spot on. Alex did an amazing job on our kitchen, which was half initiated by another tradesman. He reviewed the work and fixed many issues, always explaining and communicating well. Our kitchen had to be adapted and had some non standard cabinets but Alex was able to do all the additional features we asked for and with a great result. He also recommended some design changes which we agreed to and love. He finished the work, reviewed everything and signed off, always with a smile which is a plus. Definitely highly recommended and we will call him again in the future for sure. Thank you Alex!
R & R Brickwork ltd
Rating: 4.7 out of 5
Extension Builder in Welwyn Garden City
I've been a bricklayer for 30 years. We specialise in all forms of Brickwork and block work from garden walls to extentions, new builds, patio and driveways. Work of all sizes undertaken.
Get in touch
Latest review:
Bricklaying- 26 Aug 2021
I cannot recommend Rob and his 2 sons highly enough, they have done an excellent job completing the brickwork for our large outbuilding in good time and at a reasonable price. 3 genuinely nice blokes who are hard working and thorough, we wouldn't hesitate to use them again and have already referred for work elsewhere.
Pal
No reviews yet
Extension Builder in Welwyn Garden City
For a strong Thumbtack company description, focus on being professional, clear, and personable. You want to convince potential customers that you are the best person for their specific job.
Get in touch
Rajandeep singh
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Hi, I’m Rajandeep Singh, a reliable and hardworking tradesperson dedicated to providing high-quality workmanship and excellent customer service. I offer professional installation, repair, and maintenance services, including doors, windows, locks, handles, sealing, adjustments, and general property maintenance. I take pride in completing every job to a high standard, paying close attention to detail and ensuring customers are fully satisfied with the finished work. I am punctual, respectful, and committed to keeping work areas clean and tidy. Whether it’s a small repair or a larger installation project, I aim to deliver quality results at a fair price. Customer satisfaction is my top priority, and I believe in honest communication, reliability, and professional service from start to finish. I look forward to helping you with your next project.
Get in touch
Latest review:
Windows & Doors (uPVC & Metal)- 6 Jul 2026
Very Good work at very good price.
Garry Carpets and flooring ltd
No reviews yet
Extension Builder in Welwyn Garden City
We do carpet work flooring and bathroom, fitting fencing any kind of paint work and flat roofing
Get in touch
J Green Construction Ltd
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
I have been in the Construction industry for 15 years working for local but reliable companies. I have now established J green construction , I’m driven to succeed and provide client satisfaction in all aspects of plumbing , Refurbishments and restorations covering areas London Kent and Essex.
Get in touch
Latest review:
Bathroom Fitting- 17 Feb 2025
From start to finish the team was superb. Josh was helpful in suggesting ideas to make the most of the job. Bradley, Ray and Dave were all expert in their work and the job progressed quickly. Josh was excellent in communicating with us to advise who would be arriving the next day. As older clients we appreciated workers with whom we felt comfortable. The whole process gave us an ensuite to be proud of. Expert workmanship and a very pleasing finish. Would not hesitate to employ this contractor again.
LSTAR CONSTRUCTION LTD
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
From the first brick to the final detail – we turn your vision into reality.
Get in touch
Latest review:
When I was looking for quotes, Lukasz was the only builder who provided a fully detailed breakdown. From the start, he was professional and punctual, arriving exactly on time for our first meeting. He offered great recommendations on the best ways to approach the refurbishment and was flexible enough to let me source my own materials. Most importantly, he provides a warranty which he has already honored to fix a minor fault from another professional. It has been a pleasure trusting Lukasz and his team with my full house renovation.
Building life uk limited
Rating: 4.8 out of 5
Extension Builder in Welwyn Garden City
My skills are :Tiling :brickwork :extensions :loft conversions :partition : painting :carpentry E.t.c :you name it we do it I've got a team together who are hard working men who are very motivated on working together with our clients we always keep everyone who we do work for happy and still get recommended I work references that I can provide (We haven’t been online at my builder over a year now but we have been working out from my builder we got lots of work to prove)
Get in touch
Latest review:
Bathroom Fitting- 9 Oct 2018
Ozay arrived on time and finish the job to a high standard I've used the shower for over a month now and no leaks! Would use again!
Nick layton
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Here at City limits construction we offer all aspects of building work. From ground work and brickwork to kitchens and interiors and even landscaping and fencing. Please get in touch to discuss your needs
Get in touch
Latest review:
Conversions - General- 15 Feb 2025
Really professional. Quick, clean, competitively priced. Definitely recommend
Giorgi
No reviews yet
Extension Builder in Welwyn Garden City
A highly experienced and hardworking handyman with extensive experience in the construction and non-construction fields,able to perform a variety of maintenance duties and skills. Who have the skills to start a job from scratch and complete it according to the client's wishes.responsible, reliable and a professional in his field.who is also skilled in tiling, carpnetry,plastering ,painting and plumbing ,bricklaying and etc.doing almost all types of work that require the highest level of performance.I can also travel in and around London as desired and I also have my own team if the need arises. Last and foremost why me? Quality work, Get the job done quickly, Resposibility, Getting the job done at the best price. Kind regards
Get in touch
BLUE LOFT CONSTRUCTION LTD
No reviews yet
Extension Builder in Welwyn Garden City
Design, Build & Remodel We pride ourselves on our commitment to provide a professional and speedy service at all times, whilst maintaining the highest quality of work. We take on all types of jobs from small domestic work to larger commercial projects, all carried out to the highest standards, and at very competitive prices. We take on all building work from plumbing and electrics to conversions and extensions. Contact us today to discuss your requirements.
Get in touch
MR BUILDING
No reviews yet
Extension Builder in Welwyn Garden City
Hi we are professional builders experience more than 10 years we do all building work such as bathroom and kitchen renovation tiling flooring and loft,extensions.
Get in touch
YourLocalHelpers
New on MyBuilder
Extension Builder in Welwyn Garden City
Your Local Helpers is a trusted community based service dedicated to making everyday life easier for households and businesses. We provide reliable, friendly, and efficient help with a wide range of local tasks from home assistance and small repairs to errands and general support. Our mission is simple: connect people with dependable helpers who get things done quickly, professionally, and with care. At Your Local Helpers, we believe that no task is too small when it helps improve someone’s day. Whether it’s fixing something around the house, lending a hand with practical jobs, or providing extra support when it’s needed most, our team is committed to delivering convenience, trust, and peace of mind to every customer we serve.
Get in touch

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.