Extension Builders in Knebworth

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 3.8 (14 reviews)

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Some of our top rated extension builders in Knebworth

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NESIMI CONSTRUCTION LTD
Rating: 5 out of 5
Extension Builder in Knebworth
Nesimi construction ltd With over 18 years of experience, we specialise in bricklaying, driveways, and paving. We carry out all types of work including garden walls, patios, extensions, repairs, and general building. We pride ourselves on high-quality workmanship, reliability, and attention to detail. All jobs are completed to a high standard, on time, and at competitive prices. Friendly, honest, and professional service from start to finish.
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Latest review:
When Mr Nesimi came to undertake a pre-assessment for my front wall, he came across very professional and genuine and very honest about the work needed doing. He even suggested some changes to the work to reduce cost. The quote he gave me for the job was very reasonable and he was able to slot in my job within a week and arrive sharp on time at 8am and got on to the job straight away as I had a busy day at work for me to attend to. I notice that right from the start he was very clean and meticulous with the work and his job was of a very high quality ( compared to a job I had done by another builder 9 months ago). My neighbours also noticed this difference and were praising Mr Nesimi’s work. I would definitely recommend Mr Nesimi for any construction work as I felt he was very professional, reliable and honest and most of all the work was of high quality. I will be certainly calling him for my next job, most likely the driveway resurfacing and the attic conversion within the next year.
B.S. Plastering Services
Rating: 5 out of 5
Extension Builder in Knebworth
Hi my name is brad from kb electrical I have been an electrician for 12 years,i cover all types of work from rewires testing and inspection ccu changes all domestic work undertaken
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Latest review:
Plastering- 5 Feb 2019
Excellent work - prompt, completed job quickly and thoroughly and very tidy! Would recommend and would use again. Thanks Brad.
Handy builders stevenage
No reviews yet
Extension Builder in Knebworth
Local general building and maintenance brothers who come highly recommended and have been in the trade for a combined of 20+ years, no job too big or too small
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FF Building Contractors Ltd
No reviews yet
Extension Builder in Knebworth
FF Building Contractors Ltd are a family run business who specialise in all types of general building, construction and structural works. We have earned the reputation of providing thorough, quality workmanship from planning to completion and take pride in delivering the highest standard of work for our customers. Our aim is to deliver a personable and friendly service and ensure our customers are kept informed throughout the entire project.
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Breheny building and landscaping
Rating: 5 out of 5
Extension Builder in Knebworth
We are professional builders with 4o years experience and 3 generations in the profession, pride our selves on providing good communication and quality of work , and we try to use environmental efficiency on all our projects . 40+ years experience in the building and landscaping trade , friendly and reasonably priced . We have folling certificates Level 2 brick work Street works licence All machinery licenses digger dumper etc Water civils and electric civils license Can supply grab lorry and have waste carrying license .
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Latest review:
Breheny builders visited my property gave me a quote and did a very good good job of the patio exactly in the time frame needed also within my budget they were well mannered and reliable I would definitely recommend and I will be using again to do my drive way
GLJ Construction Ltd
Rating: 5 out of 5
Extension Builder in Knebworth
GLJ Construction Ltd , Building and Brickwork contractors in Hertfordshire since 2012.
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Latest review:
Facing Brickwork to an external terrace area, for a new Law firm. Excellent quality and very professional. All works completed on programme too. I would highly recommend Gavin and his team.
Homerunbuilders Ltd
Rating: 5 out of 5
Extension Builder in Knebworth
At Home Run Builders, we are experienced carpenters and builders specialising in all types of renovation, refurbishment and building work. From small improvements and repairs to complete home renovations and extensions, we provide a reliable and professional service tailored to every customer. Our services include carpentry and joinery, kitchens and bathrooms, flooring, plastering, decorating, structural alterations, loft conversions and home extensions. We take pride in delivering high-quality workmanship, attention to detail and excellent customer service. Whether you are looking to modernise a single room, renovate your entire property or create more space with an extension, Home Run Builders can help bring your ideas to life. We work closely with our customers from the initial consultation through to completion, making sure every project is completed to a high standard and with minimum stress. If you are planning a renovation, extension or building project, Home Run Builders are here to help.
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Latest review:
Hard Flooring- 16 Aug 2026
Put this job request up with very short notice and this was not a problem. Delivered a high level of work quality and even quoted for other work. Highly highly recommended. Thanks
Vines Construction Ltd
No reviews yet
Extension Builder in Knebworth
Vines Construction Ltd Specialise in all areas of the residential construction industry. Bespoke extensions & boutique refurbishments are our forte.
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Aston Knights Construction ltd
New on MyBuilder
Extension Builder in Knebworth
Aston Knights Construction | Structural Specialists & Main Contractors We are a high-specification Main Contractor operating across Hertfordshire, specializing in complex residential extensions, structural transformations, and high-end superstructure builds. Rooted in commercial-grade structural execution, we bring heavy-engineering standards—including complex steel arrays, high-load masonry, and precision groundworks—to domestic residential projects. We deliver architectural design intent to millimeter tolerances. Our Core Capabilities: Structural Extension Shells: Complete groundworks, steel fabrication/erection, precision masonry, and roof-to-watertight packages. Structural Alterations & Steelwork: Complex RSJ installation, load-bearing wall removals, and architectural reconfigurations. Turnkey Extensions: End-to-end main contracting delivered under formal JCT contracts. The Aston Knights Standard: Engineering Precision: All works executed strictly to structural calculations, building control regulations, and inspector sign-off. Immaculate Site Culture: Safe, clean, and organized sites managed with direct communication and professional site discipline. Fixed Transparent Pricing: Fully itemized line-item proposals with com
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DJP BUILDING SERVICES
No reviews yet
Extension Builder in Knebworth
General building company specialising in groundwork, brickwork and plastering.
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GA Living Spaces Ltd
Rating: 5 out of 5
Extension Builder in Knebworth
George Alexander Living Spaces is a family-run business specialising creating and re-novating "Living Spaces" within residential properties. As a company, with over 30 years experience, we specialise in all aspects of building works; from constructing a timber frame house from scratch; extensions; loft & garage conversions; refurbishments; designing and manufacturing your new kitchen; bathroom or stone worktops - through to boarding and plastering internal walls!
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Latest review:
Kitchen Fitting- 11 Dec 2018
Our kitchen looks very nice and bright and everything we required has been achieved, at a competitive price. The team were very polite,considerate and hardworking. There have been a couple of hold ups along the way, but we are pleased with the finished product.
CARVE Engineering Co Ltd
Rating: 1 out of 5
Extension Builder in Knebworth
We undertake large and small construction rebuild projects, house extension and loft conversion, shop design and decoration, home design and decoration, customized furniture. We can provide professional drawing and floor plan as well.
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Latest review:
Extensions- 19 Sep 2022
Man Ho or Calvin Ho' or Man Fu Ho, who owns Carve Engineering Co. Ltd. He also has a Hong Kong branch carve-eng.com . I didn't know he subcontracted the whole project to a group of Chinese mainlanders who couldn't speak English. And he asked a British Gas gas engineer to sign off the plumbing work. I obtained the planning in December 2021. The work started on 31/1/2022 and almost finished now 19/9/2022. It supposed to end in three months time as they promised. It's only a single storey side extension and shouldn't be left unfinished with pipes broke. The workers only came to work once a week and sometimes the work stopped for a month or so. The price included the purchase of a boiler and installation. But there's no timer or thermostat and I was asked to purchase these and install them with extra cost. The workers' van broke down five times and they didn't turn up for five different days. There's no windowsill and they called this a standard window people would install. The exterior wall was painted inconsistent to our original wall and I had to argue to get them pebbledash and repainted. They left the fences on our neighbours. The pipes are still leaking. Shower leaked for 3 months. They even charged extra for the electricity sockets they installed in our kitchen. They took down the mains water supply switch and never install it back so our house has no in house mains water stop valve! They didn't hoover and didn't have a hoover. Avoid this company!
Buildrow property services ltd
Rating: 5 out of 5
Extension Builder in Knebworth
We are company that cover all construction work and trades
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Latest review:
Job was a single story extension and fit kitchen,work was completed to a very high standard and was professional at all times,arrived on time every day and work was completed on time. Was very happy with the finished product.
Herts sparks ltd
No reviews yet
Extension Builder in Knebworth
At Herts Sparks, we specialize in delivering high-standard electrical installations and bespoke designs tailored to your needs. With a keen eye for detail and a commitment to quality, we work closely with our customers to bring their vision to life-whether it’s a stylish home renovation, a cutting-edge commercial fit-out, or a complex industrial project. Our expert team ensures every installation meets the highest safety and efficiency standards while maintaining competitive pricing. From concept to completion, Herts Sparks is your trusted partner for reliable, professional, and innovative electrical solutions. Quality. Precision. Affordability. That’s the Herts Sparks promise.
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S&b
New on MyBuilder
Extension Builder in Knebworth
I’m doing great job. I have experience 18 years.
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The little joinery co
No reviews yet
Extension Builder in Knebworth
Bespoke building company based in Harpenden. Regularly completing one of a kind extensions, loft conversions and development projects to a high standard.
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3.8

Top rated Extension Builders

Our Extension Builders in Knebworth, are rated 3.8 out of 5 based on 14 reviews from customers like you.

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

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

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

What are the hourly rates of extension builders in Knebworth?

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

Find extension builders in Knebworth with MyBuilder

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

Step 2: Compare different extension builders in Knebworth

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

Step 3: Hire Knebworth extension builders with confidence

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

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

What to ask a Knebworth extension builder before hiring?

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

An extension builder in Knebworth 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 Knebworth 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 Knebworth?

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 Knebworth 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 Knebworth 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 Knebworth

Can an extension builder in Knebworth help with planning permission?

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

Many Knebworth 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 Knebworth help with materials and finishes?

Yes, most extension builders in Knebworth 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.