Extension Builders in Hertfordshire

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 Hertfordshire

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Sinevir Construction
Rating: 5 out of 5
Extension Builder in Hertfordshire
Sinevir Construction Ltd is a trusted construction company based near London, proudly serving the capital and surrounding areas. We specialise in residential and commercial projects, including new builds, extensions, refurbishments, and structural works. Our team of qualified professionals is committed to: High standards of workmanship Full regulatory compliance Clear and honest communication throughout every stage of the project Whether it's a small private renovation or a complex public contract, we approach each project with care, precision, and professionalism. What sets us apart: ✅ Construction Online Gold Member ✅ Skilled and experienced workforce ✅ NEBOSH-certified site safety supervision ✅ CHAS and SSIP-accredited for health & safety standards ✅ Fully insured, giving clients peace of mind ✅ Transparent pricing and realistic scheduling ✅ Respect for architectural heritage and local communities ✅ Competitive rates without compromising on quality We believe every property deserves thoughtful construction and reliable service — and at Sinevir Construction Ltd, we proudly deliver both.
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Latest review:
Extensions- 27 Mar 2026
Ruslan was excellent at his craft. Very hard working, very clean and professional with a great attitude. Would highly recommend this company
Maytrix Construction Limited
Rating: 5 out of 5
Extension Builder in Hertfordshire
Maytrix Construction Ltd was formed in 2012, our management team and key staff has over 90 years of combined experience delivering high end construction projects, so you can be confident that our unique blend of expertise and experience means we deliver schemes to the exact level of detail demanded by our clients. Our Professional services include (not limited to): New Build Residential Property. Extensions and Alterations. Commercial Property. Educational & Public Sector.
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Latest review:
New build brickwork and block work done on budget and on time. Workmanship excellent. Maytrix kept me informed on progress and were very helpful tradesmen who were always on time.
U & A Builder
Rating: 4.9 out of 5
Extension Builder in Hertfordshire
We've been ground-workers for over 16 years now and we've got lots of experience. We specialise in many aspects such as groundwork, driveways, landscape gardening, underpinning, paving, foundations, extensions, fencing and general building work. Our jobs have a warranty and also guarantee to complete all jobs to a high standard.
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Latest review:
Landscaping- 19 Mar 2024
Completely professional from start to finish. Urim and Aryam are both excellent communicators, which made a huge difference in planning the drainage for our patio, and rebuilding our front steps. We had every confidence in them from the outset and they fulfilled all our expectations. A great team!
UK NAMA Constructions Ltd
Rating: 5 out of 5
Extension Builder in Hertfordshire
Garden Fencing, Garden Decking, Artificial Grass, Wooden Floor Laminating, Decorating, Partitions.
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Latest review:
Carpentry- 28 Jan 2026
Ali did an exceptional job designing and building our staircase, and I couldn’t be happier with the result. From start to finish, he was a complete gentleman — polite, respectful, and a pleasure to deal with. Ali is clearly a true specialist at what he does. His knowledge, attention to detail, and confidence in his craft really stood out. He was able to design and install the entire staircase in just one day, which was genuinely impressive given the quality of the finish. He worked efficiently, kept the area tidy, and took great pride in his work. It’s rare to find someone who combines skill, professionalism, and good nature so well. I would highly recommend Ali to anyone looking for a high-quality staircase installed by a true expert.
Smart Constructors Ltd
Rating: 5 out of 5
Extension Builder in Hertfordshire
We represent a new construction company with many fields of activity, such as meintenance, cleaning, extensions a.s.o. We are more than happy to tackle any chalange.
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Latest review:
Handyman- 9 Aug 2019
Very happy, good (fair not cheap) price. Adrian contacted me, arranged to come quite quickly, efficient and completed the job in good time... left site nice and tidy. Would recommend 😀 Thanks Adrian
ATW Construction Services
Rating: 5 out of 5
Extension Builder in Hertfordshire
I am a local builder with over 20 years' experience. I am a time served Advanced City & Guilds Bricklayer. I am hands on with a small team that work alongside me. I am reliable and offer a professional service. Most of my customers are repeat business. Member of the Federation of Master Builders.
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Latest review:
Gas Work- 4 Dec 2018
A really neat and professional finish. Lots of good advice given. Would recommend to anyone.
Hertford Build Ltd.
Rating: 5 out of 5
Extension Builder in Hertfordshire
Hertford Build Ltd specialises in all aspects of building, including bespoke carpentry, extensions, garage conversions, kitchens and garden out buildings. We pride ourselves on being reliable, efficient and professional and can offer free quotations and advice on all your building needs. We understand that work being completed at your home can be stressful. For this reason we carry out every job as if it were our own and ensure it runs smoothly, on time and completed to the highest standard.
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Latest review:
Quick and efficient workmanship. Quality of work exceptional at a great price.
Choice Build
Rating: 5 out of 5
Extension Builder in Hertfordshire
We are a small team specialising in plastering, carpentry and building. We can carry out full refurbishments, removal of load bearing walls, extensions, garden rooms, garage conversions and much more. With over 15 years each in our trades we strive to complete every job to the highest finish and feel combing plastering and carpentry we have the skill sets to do this. Electric and plumbing works are carried out by qualified tradesmen
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Latest review:
Restoration & Refurbishment- 14 Aug 2020
Excellent work ethic and attention to details. All-round nice guys to have around, finished the job on time and left in a tidy manner.
SFL Construction Ltd
Rating: 5 out of 5
Extension Builder in Hertfordshire
SFL Construction is a Hertfordshire-based construction company, building a wide range of structures and completing all construction phases from the foundation to the roof and everything in between. Our team brings years of experience and expertise to every project we undertake.
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Latest review:
Ryann and his team first completed a multiple room ground floor extension for us, including the installation of a new kitchen and bathroom. We were so pleased with the work that we asked him to build an outdoor garden room from scratch and completely refurbish our other bathrooms. We have always found Ryann to be friendly, punctual, knowledgeable and honest and I am more than happy to give my recommendation.
Hunbuild Ltd
Rating: 5 out of 5
Extension Builder in Hertfordshire
With over 25 years of experience in construction Open Plan Solutions is regarded as one of the most successful companies based in St. Albans and the surrounding counties working on both private and commercial property development. Open Plan Solutions provides a successful track record within a safe environment for the community it works in. Our speciality in providing construction needs makes us the first choice amongst customers looking for quality services. We strive to deliver all construction on time and to budget – and we consistently do, which is why our client base has continued to grow and we consider ourselves to be the number one building and construction experts covering St. Albans, Hertfordshire and surrounding areas.
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Latest review:
Restoration & Refurbishment- 20 May 2026
Excellent service from a very professional team. They removed two chimney breasts for us, turned up right on time, and finished the work to a very good standard. They also did a great job of protecting the house from dust while working. We are very happy with the final result and would definitely recommend them.
Painting & Decorating
Rating: 5 out of 5
Extension Builder in Hertfordshire
Probably the most important characteristic that define our team is that we like what we are doing and we take pride in any single job.We do our work in detail and make sure every step on prep work is done properly as well as the materials we using are a good quality and long lasting.We are doing high quality jobs,at resonable prices,both residential and commercial.If you are looking for painters you can trust and have your painting job done properly&clean then we are the ones you're after
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Latest review:
Handyman- 8 Jun 2026
Absolutely fantastic job. Julian was really friendly, arrived on time, did an amazing job fitting the wall panels and cleaned up afterwards. I cannot recommend him highly enough, and will certainly be using his services again
R Rexha Builders
Rating: 5 out of 5
Extension Builder in Hertfordshire
Extensions - Porches - Garages - Lofts conversion - Kitchen fitting - Bathrooms - Carpentry - Repointing - Painting -Decorating (interior / exterior)
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Latest review:
Extensions- 21 Sep 2019
Ray has done an outstanding job with the new extension. He has shown great attention to detail and accommodated every request. The result is one that we are extremely happy with. He installed a new bathroom downstairs complete with all necessary pipework and a new utility closet with exits for the washing and dryer. Clearly Ray has a very broad set of skills, from electricity to building to carpentry, plumbing and roofing. He really was the one stop shop to make this extension a reality and has a network of people he can call onto if required. He is certainly someone that takes pride in his work and wants a job well done as evidenced by his work. I recommend Ray without a doubt and I'm sure our paths will cross again. Thank you Ray!
Philip J Pulzer
Rating: 4.7 out of 5
Extension Builder in Hertfordshire
As a design and build contractor, we will produce drawing for both planning approval and building regulation. We will then provide a detailed estimate of building costs. If we do win the building co tract then all architectural design cost will be free of charge.
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Latest review:
Extensions- 11 Feb 2019
Completed job on expected timeline and assisted when challenges came up
SAS Carpentry
Rating: 5 out of 5
Extension Builder in Hertfordshire
Complete building service Extension, Conversions and full refurbisment service supplied. Covering all trade services. Groundworks Bricklaying Gas registerd plumbing service Niceic Electrical service Carpentry 1st,2nd fix works Plastering Kitchen,bathroom and bedrooms supplied and fitted Full decorating service Floor and wall tiling All work completed to the highest standards by competent time served tradesman.
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Latest review:
Carpentry- 20 Nov 2019
Great service, will definitely use again!
AJ Construction
Rating: 4.7 out of 5
Extension Builder in Hertfordshire
Me and my team are very friendly, hard working, dedicated and ambitious builders who always put the customers wishes first. our motto is "create a space to enjoy” We specialise in carpentry and brickwork however we have a lot of experience in every aspect of building.
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Latest review:
Conversions - General- 21 Dec 2025
Joe and his team were amazing from start to finish. Communication was brilliant, Joe kept us updated every step of the project. The standard of work was excellent and we are so pleased with how the garage conversion turned out. Thank you to Joe and his team, we will definitely use again and will recommend to family and friends.
D&N construction
Rating: 5 out of 5
Extension Builder in Hertfordshire
D&N CONSTRUCTION ARE A POTTERS BAR BASED BUILDING AND HOME IMPROVEMENT COMPANY WITH MANY YEARS OF PROFESSIONAL EXPERIENCE. Whether it’s improving your outdoor space, or extending your home, D&N Construction is here to help you every step of the way. We have many years of experience in renovations and all building work At D&N Construction , we’ve built our livelihoods on building peoples’ dreams across Hertfordshire. we’ve experienced it all we can help you . No job is too small or too big!
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Latest review:
Carpentry- 8 Oct 2025
Nick fitted a single pine internal door for me in the Letchworth area. He was very easy to work with, communicated promptly and clearly throughout, and was neat and tidy during the installation. I’d happily recommend his services.

3.7

Top rated Extension Builders

Our Extension Builders in Hertfordshire, 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 Hertfordshire?

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

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

What are the hourly rates of extension builders in Hertfordshire?

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

Find extension builders in Hertfordshire with MyBuilder

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

Step 2: Compare different extension builders in Hertfordshire

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

Step 3: Hire Hertfordshire extension builders with confidence

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

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

What to ask a Hertfordshire extension builder before hiring?

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

An extension builder in Hertfordshire 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 Hertfordshire 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 Hertfordshire?

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 Hertfordshire 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 Hertfordshire 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 Hertfordshire

Can an extension builder in Hertfordshire help with planning permission?

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

Many Hertfordshire 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 Hertfordshire help with materials and finishes?

Yes, most extension builders in Hertfordshire 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.