Extension Builders in Harpenden

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 3.6 (12 reviews)

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Some of our top rated extension builders in Harpenden

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Urwin services
No reviews yet
Extension Builder in Harpenden
We are a driveway clearance and demolition specialist, all aspects of clearance and demolition undertaken, competitive rates clean and efficient working in home counties and north London
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A & A Build and Design
No reviews yet
Extension Builder in Harpenden
Refurbishment, Extensions, New build, Design and Maintenance of any domestic building project.
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Jales construction
No reviews yet
Extension Builder in Harpenden
Hi my name is Marcelo, I have been in the building trade for over twenty years. I’m good at what I do and I take pride in my work. I always make sure I do it right and up to a professional standard.
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Arch Construction and Project Management Ltd
Rating: 5 out of 5
Extension Builder in Harpenden
Arch Construction and Project Management Ltd is specialist of structural engineering, structural alterations,restoration, extensions, loft conversions and in middle&large sized projects on highest standard. We offer full building site and/or project management from concept to completion based on 22 years experience in construction industry with hassle and frustration free experience.
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Latest review:
Extensions- 12 Jan 2023
George and his team did an excellent job in building our extension and dealing patiently with our requests or changes. We had weekly face to face meetings with George and he would respond promptly to any issue. A very professional approach to the build project and an excellent result of build quality.
A and B Gardening LTD
Rating: 5 out of 5
Extension Builder in Harpenden
Here at A&B Group, we have years of hands‑on experience across a wide range of trade needs, from landscaping to renovation and refurbishment projects, our company brings reliable expertise to every job we take on. We proudly serve clients throughout Hitchin and the surrounding areas, offering flexible travel for projects of all sizes. Our specialist skills include high‑quality finishing, problem‑solving on complex builds, and delivering clean, precise workmanship from start to finish. Customers choose us because we prioritise clear communication, honest advice, and craftsmanship that stands the test of time, ensuring every project is completed to the highest standard. Delivering your work from start to finish, with near all trades covered in-house. Built on Trust. Delivered with Quality. Check out our instagram: aandbgardening aandbconstructiongw
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Latest review:
Hard Flooring- 1 Sep 2026
Absolutely brilliant guys fantastic job doing my floors they had a problem putting it down as I left the packs out side and the wood swelled from the rain but the managed to lay it after hours of trying. Thanks Dan and partner brilliant job done
Dream Home Design and Build Limited
No reviews yet
Extension Builder in Harpenden
Although we are new to this site and yet to gain feedback, we are a team of experienced, knowledgeable and personable professionals ready to tackle your next project. We have an excellent reputation for completing projects on time and within budget. You are welcome to contact any of our satisfied client, just ask us for details. Feel free to contact us and we can discuss your project with a view to providing you with an exceptional service.
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Irz construction ltd
Rating: 5 out of 5
Extension Builder in Harpenden
Irz construction ltd was created 5 years ago always were recommend to costumers all around London Type of jobs we do Refurbishments Extension Loft conversation Gardening Driveways Painting decorating All projects we did are available to visit and see It in person also ask the owners about their experience with us The director has been 7 years on this industry previously managing another successful construction company
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Latest review:
Restoration & Refurbishment- 19 Nov 2019
Iljaz and his Team were brilliant! I was slightly concerned having no reviews. They found the leak, fixed it and patched up the wall in very tidy and professional manner. He did say he wouldn't be able to come today and updated me, however he made time to come in-between his day to sort out my issue. Not many true trades people like this and very honest and stuck to his word. I would definitely recommend him and would not hesitate to use his team again. Thank Iljaz!
S&b
New on MyBuilder
Extension Builder in Harpenden
I’m doing great job. I have experience 18 years.
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CPK Building & Maintenance
No reviews yet
Extension Builder in Harpenden
Hi, I'm chris from CPK building & maintenance we are a small building company, we take on all kinds of building and maintenance jobs offering a great affordable service. Over 15 years experience.
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KFN Plastering & Property Maintenance
Rating: 4.8 out of 5
Extension Builder in Harpenden
KFN Plastering & Property Maintenance is a trusted and professional company with over 18 years of industry experience. Based in Watford, we take pride in delivering exceptional workmanship, attention to detail, and outstanding customer service on every project. Fully vetted and committed to the highest standards, we provide reliable plastering and property maintenance services tailored to meet our clients’ needs. Whether undertaking small repairs or larger renovation projects, we consistently deliver a high-quality finish with a focus on professionalism, cleanliness, and customer satisfaction.
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Latest review:
Plastering- 19 Jul 2026
Excellent plasterer! Karl did an outstanding job, and the quality of the plastering was excellent, with a smooth, professional finish throughout. He turned up on time every day, completed the job on schedule, kept everything tidy, and was friendly and easy to deal with. I’m very happy with the result and would definitely recommend Karl to anyone looking for a reliable and skilled plasterer.
Fennel Carpentry and Construction
New on MyBuilder
Extension Builder in Harpenden
Hi, I’m George, founder of Fennel Carpentry and Construction. Carpentry is my trade, but my experience goes far beyond that. Over the past three years I’ve worked on new builds, renovations and extensions, developing a strong understanding of multiple trades to deliver high-quality work from start to finish. Before that, I specialised in carpentry and handyman services, taking on everything from hanging doors and fitting door linings to the smaller jobs that make a big difference. I also have over two years’ landscaping experience, which I still enjoy today, and having a plasterer as a dad means I’ve picked up solid plastering skills too. I’m proud to be known for being reliable, honest, hardworking and easy to communicate with. I take pride in every job, no matter the size, and always aim to leave my customers happy. Most of my work is local, but I’m always happy to travel for the right project. If you’re looking for a trusted tradesman, I’d be delighted to help. George Fennel Carpentry and Construction
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Cosybuild ltd
No reviews yet
Extension Builder in Harpenden
Cosy Build is a new chapter in our journey, rebranding after over 10 years of trusted building and construction expertise across Harpenden, Radlett, Hertfordshire, North London, and surrounding areas. Based in Hertfordshire, our professional, reliable tradesmen serve St Albans, Harpenden, Radlett, North London, and nearby regions, delivering high-quality building services with a commitment to excellence. Formerly known as Luan Ajazi Home Improvements. Cosy Build is a family-run, customer-focused building company with deep roots in the Hertfordshire and North London construction industry. Our team consist of: Highly skilled craftsmen with decades of combined experience. Fully insured and certified professionals for your peace of mind. Local experts who understand the architectural styles and regulations of the area. What We Do & What We Care About Cosy Build is a family-run, customer-focused building company with deep roots in the Hertfordshire and North London construction industry. We specialise in: Loft conversions – Maximising your home's space and value. Loft conversions – Maximising your home's space and value. Home extensions – Seamlessly blending new spaces with your existing property. Renovations – Modernisin
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AK Bespoke carpentry & construction
No reviews yet
Extension Builder in Harpenden
I’m a qualified carpenter with a background carrying out extensions, loft conversions and new build carpentry packages. I’m new to MyBuilder, as I’ve only just recently formed my company. This decision was made having been project managing and supervising on extensions, loft conversions and renovation work for a Building company since 2015. Please don’t be alarmed that I have no feedback as yet, photos of my work clearly demonstrate that the sky really is the limit.
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Building services
Rating: 4.7 out of 5
Extension Builder in Harpenden
We are specialists in Loft conversion, extension, refurbishment, carpentry and decorating projects over the past 20 years, we provide all type of general building services & refurbishment projects with our skilled and reliable team. We are a company you can trust for all Commercial, Domestic services. Contact us for Free Quotation!
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Latest review:
Carpentry- 7 Aug 2015
Excellent service and very professionally carried out. Rahim came round at a time that was convenient for me and charged a very fair price for the job. Would certainly recommend.
ASG Developments - Herts
No reviews yet
Extension Builder in Harpenden
Free Architectural Plans Included with every build. Crafting timeless spaces with precision, passion, and purpose. Welcome to ASG, where visionary architecture meets exceptional construction. From concept to completion, we bring your ideas to life with innovative design, sustainable practices, and uncompromising craftsmanship. Whether you're planning a custom home, commercial space, or renovation, we deliver spaces that reflect your vision — beautifully and efficiently.
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d&d building & property maintenance
No reviews yet
Extension Builder in Harpenden
We are a general building and property maintenance company that builds houses, extentions ,loft conversions and undertakes any house hold referbishments .Our company also provides commercial building works for various schools local to us who will be happy to provide references. With over 25 years years experience our aim is to make sure the customer is always satisfied.
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3.6

Top rated Extension Builders

Our Extension Builders in Harpenden, are rated 3.6 out of 5 based on 12 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 Harpenden?

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 Harpenden 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 Harpenden who are available and interested can respond to your post.

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

What are the hourly rates of extension builders in Harpenden?

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

Find extension builders in Harpenden with MyBuilder

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

Step 2: Compare different extension builders in Harpenden

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

Step 3: Hire Harpenden extension builders with confidence

After gathering all the information and quotes from your chosen home extension builders in Harpenden, 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.

Harpenden extension builders are ready to help. Use MyBuilder today to find the right professional for your home extension.

What to ask a Harpenden extension builder before hiring?

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

An extension builder in Harpenden 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 Harpenden 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 Harpenden?

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 Harpenden 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 Harpenden 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 Harpenden

Can an extension builder in Harpenden help with planning permission?

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

Many Harpenden 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 Harpenden help with materials and finishes?

Yes, most extension builders in Harpenden 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.