Extension Builders in Welwyn Garden City

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 3.9 (16 reviews)

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Some of our top rated extension builders in Welwyn Garden City

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VIZ GROUP
No reviews yet
Extension Builder in Welwyn Garden City
Viz Group is the builder of choice when it comes to residential and commercial construction projects in London With over 20 years of experience and hundreds of projects, you can rest assured that our team are able to tackle any of your building needs.
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Hamilton builders group ltd
New on MyBuilder
Extension Builder in Welwyn Garden City
Hamilton Builders Group is a trusted, family-run building company with over 40 years of experience in the building trade. As a third-generation family business, we pride ourselves on providing a reliable, professional and personal service to every customer. We specialise in home extensions, renovations, new builds and general building work across Hitchin, Stevenage, Letchworth, Baldock and the wider Hertfordshire area. From smaller home improvements and repairs to larger extensions and complete property renovations, we have the experience and knowledge to manage projects from start to finish. We believe that good communication, honest advice and quality workmanship are just as important as the finished result. We work closely with our customers throughout every stage of a project, paying close attention to detail and taking pride in delivering work to a high standard. Whether you already have plans or simply have an idea you would like to discuss, we are always happy to offer advice and provide a free, no-obligation quotation. At Hamilton Builders Group, our reputation is built on experience, quality and putting our customers first.
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GRAND DESIGNS INTERNATIONAL LTD
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Grand Designs International (GD) | Architectural, Engineering & Construction Services At Grand Designs International (GD), we are dedicated to delivering high-quality architectural, engineering, and construction services tailored to meet our clients’ unique needs. Backed by over 20 years of expertise, our team specializes in transforming visions into reality—whether you're planning a new build, home extension, loft conversion, or full-scale renovation. With a strong foundation in innovation, sustainability, and precision, we provide end-to-end project solutions, from initial design and planning permissions to structural calculations and final construction. Our commitment to quality, efficiency, and client satisfaction ensures that every project is completed to the highest standards. Why Choose Grand Designs International? ✅ Full-Service Expertise – From architectural planning to construction, we handle every stage seamlessly. ✅ Planning & Building Regulations Specialists – We navigate approvals efficiently to prevent delays. ✅ Experienced & Certified Team – Qualified engineers, architects, and builders with a proven track record. ✅ Tailored Solutions – Every project is custom-designed to meet your style, space, and budget needs. ✅ Transparent Pricing & Project Management – No hidden costs, just reliable service with regular updates. ✅ Fast Turnaround & On-Time Delivery – We work efficiently without compromising quality. Our Services 🏡 Architectural & Planning Services Planning Applications & Building Regulations Approval Concept & Detailed Design Interior Design & Space Planning 3D Visualizations & Rendering Enforcement & Retrospective Planning 🏗️ Structural & Engineering Design Structural Calculations & Drawings Civil & Structural Engineering Services Quantity Estimation & Cost Planning 🔨 Construction & Building Services Home Extensions & Rear Extensions Dormer Loft Conversions & Flat Conversions New Build Homes & Full Renovations Project Management & Site Supervision Construction Planning, Procurement & Logistics Quality Control & Safety Management At Grand Designs International, we believe in delivering excellence, one project at a time. Our reputation for integrity, professionalism, and top-tier craftsmanship makes us the preferred choice for homeowners and businesses across London and beyond. 📞 Get in Touch Today! Let’s discuss your project and bring your dream home to life.
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Latest review:
★★★★★ Highly Recommended! I had an existing 3-bedroom rundown property and contacted multiple builders before meeting Director Mr. Q Nawaz. From our first meeting, I was impressed by his ideas and the fact that Grand Designs could provide all services in-house. Initially, I proceeded only with the planning application to see if what he promised was possible—and YES, he delivered! My application was approved as he assured me. Seeing this success, I entrusted them with the entire construction project, and Grand Designs completed it within just 6 months, despite the challenges of COVID-19. Not only did they build my project, but they also added significant value to the development. I’m proud to have worked with them, and their exceptional work on my St Albans development is now featured in their portfolio. Within one year, the value of my property increased by £500,000—a testament to their expertise! Extremely professional, highly skilled, and very reasonably priced. You don’t need to go anywhere else—Grand Designs is the complete package!
Inspired Creations London Ltd
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
We undertake residential and general construction projects including extensions, loft conversions and renovations. We also manufacture and install bespoke kitchens, bedroom and all kinds of fitted furniture.
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Latest review:
Extensions- 8 Dec 2021
Sukh and his team are tidy, experienced and skilled. The standard of work throughout the house is excellent. Will be keeping their contact details for any future projects. Would definitely recommend.
On
No reviews yet
Extension Builder in Welwyn Garden City
General building work jobs experience 16 years within the construction industry. I have completed Varius extensions of all kinds. we have a great team here that can provide the quality and reassurance you are seeking.As we pride ourself in only high end and professional works for all my customers.
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Marius dumitriu
No reviews yet
Extension Builder in Welwyn Garden City
Your builder is here
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SOLO CONSTRUCTION MANAGEMENT LTD
No reviews yet
Extension Builder in Welwyn Garden City
Solo Construction is a leading design and build construction with an established and growing up reputation. Our extensive experience in London what allows us to understand and manage all risks and complexity in modern projects. Offering full architectural and interior design services what allows our clients to enjoy having their projects being in one safe hand from idea to completion. We undertake all types of building works from small refurbishment to new build.
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CB Electrical & Networking Services Limited
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Specialising in providing comprehensive range of electrical services including Design, Installation, Testing and Commissioning, covering all sectors from Domestic and General to Industrial environments. We are dedicated to provide reliable and cost effective service with 100% customer satisfaction. With a focus on safety and efficiency, our team is committed to delivering excellence in every project. - NAPIT registered - Fully insured - Excellent workmanship
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Latest review:
Electrical- 17 Mar 2025
Cristi did two great jobs for me and installed the Alarm systems professionally and efficiently. I'll definitely recommend him, as I've added him to my Electrical Contractors list moving forward.
Lanext Group Ltd
No reviews yet
Extension Builder in Welwyn Garden City
We are a family-run British building firm offering high-quality workmanship rooted in traditional building practices. With generations of experience and a strong commitment to craftsmanship, we undertake a wide range of projects, both large and small. We pride ourselves on delivering dependable, professional services with a personal touch, offering free quotes, competitive pricing and guarantees for complete peace of mind.
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Niall paine
No reviews yet
Extension Builder in Welwyn Garden City
I have been in the bricklaying trade for 17 years, fully qualified nvq 2. Work to a high standard, have worked on all types of bricklaying jobs from sites with multiple houses to small garden walls and repointing. Reliable and hardworking.
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ZBRUCH TEAM LIMITED
No reviews yet
Extension Builder in Welwyn Garden City
We are doing all types of dry lining jobs: Metal stud partitions, metal ceiling, grid ceilings, all kinds of plaster-boarding, tacking and dot&dab, insulation, loft insulation, plastering and tape and joint, loft conversion and any type house extension, We can supply all materials as well Also we can do transportation job,if people are moving in and out. Please be in touch with us and we will deal with prices Kind regards ZBRUCH TEAM
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Terbuni building services
No reviews yet
Extension Builder in Welwyn Garden City
Undertaking majority of building works with high end finishes and happy customers ,don’t hesitate to contact us for a free quote ,will go around to check what I have done all my previous jobs can be seen Thanks a lot 😉
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Lotus Trinity Limited
No reviews yet
Extension Builder in Welwyn Garden City
At Lotus Trinity we deliver state of art workmanship, exquisite customer service, quick turnarounds and competitive prices with efficiency and pride. Our friendly project managers will work one-to-one with you to ensure that each project is completed to your highest satisfaction. Founded by Sabin, who has over 20 years experience of working in the construction industry, along with our project managers with a similar level of expertise, we have knowledge and experience of the industry and nearly every niche within it. We strive to make the building process as stress free for our clients as possible throughout transparency and by keeping them up to date on everything that we do while delivering the highest quality work. Constant communication and quality control. Our clients projects are our business cards.
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Build tech
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Welcome to our add. Professional Building Company Professional experts in all types of construction have worked on Victorian and Georgian properties, giving them a slick new light and converting them into modern and contemporary living spaces. Expect transparent open-book pricing, quality workmanship, and 24/7 communication.
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Latest review:
Extensions- 28 May 2019
Ayaz is a professional and a really nice man.
N&D Brickwork Construction
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Over 17 years experience doing all building work, building houses, extensions, garden walls and paving. Customer guarantee satisfaction
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Latest review:
Extensions- 1 Jul 2021
Great job done by Naim and his team. He expressed interest in the job as soon as I posted. If it hadn't been for some wet weather the job would have been completed much sooner in the timescale he quoted. There was one small issue some time after the job was completed. I only called Naim once and he arranged a day to come fix it. We're very pleased with the finish, we would give future work to him and also recommend him to friends & family.
22g construction limited
Rating: 5 out of 5
Extension Builder in Welwyn Garden City
Hi , we are here on this platform to make your dream house into reality , with 20years of experience in all trades and expertise we will make sure you get the best service , so chose us for any kind of construction work . Thanks
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Latest review:
22g construction did my bathroom refurbished they did very good job more than my expectation I am happy to recommend 22 G construction anyone who’s looking refurbishment extension or any other work

3.9

Top rated Extension Builders

Our Extension Builders in Welwyn Garden City, are rated 3.9 out of 5 based on 16 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.