Extension Builders in Knebworth

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 Knebworth

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Build tech
Rating: 5 out of 5
Extension Builder in Knebworth
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.
NKN HOME CREATIONS LIMITED
Rating: 5 out of 5
Extension Builder in Knebworth
We are a reliable and experienced construction company committed to delivering high-quality workmanship with care and attention to detail. We specialize in home extensions, refurbishments, new builds, and loft conversions, ensuring every project is completed safely, professionally, and to the highest standards.
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Latest review:
Plastering- 2 Feb 2026
Happy with work, left job site tidy and clean. Will be happy to use company for future work. Thanks
Rares Cristian Lupu
Rating: 5 out of 5
Extension Builder in Knebworth
I am a sole trader working for myself for more than 10 years. Family experience over 35 years. I deliver all services from painting, dexorating, bathrooms, kitchens, full house builds, loft conversions, rear / side extensions, landscaping, plastering and plumbing/electric. Reliable and respectful to all my clients!
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Latest review:
had an excellent experience working with Cristian on my bathroom project. From start to finish, his work exceeded all expectations. Cristian was professional, attentive to my needs, and incredibly detail-oriented. His craftsmanship and commitment to quality were evident in every aspect of the project, and he transformed the space beautifully. He kept communication clear and made sure everything was completed on time and according to my vision. I am thrilled with the results and highly recommend his services.
Future Home Constructions
Rating: 5 out of 5
Extension Builder in Knebworth
Future Home Constructions Ltd is a company that understands and appreciates every client’s uniqueness. We always work hand to hand with our clients to make sure that the final result is how you imagine. We specialize in: extensions, brickwork, plumbing, and much more. However, we do appreciate that you might not know if your project will meet your budget, so we offer a free of charge estimate on your next project. You don’t wait for your dreams to happen, you call us and we make them happen.
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Latest review:
Bricklaying- 25 May 2022
Top notch builders! We used Future Home Construction to build our large wrapround extension. They are a reliable family-owned company who showed up on time, worked hard, sometimes working 6 days a week including Bank Holidays. The team worked with great care and professionalism and were very informative, walking me through the process and offering me solutions to problems. We have been very impressed with the high standard of work carried out on our house and are delighted with the result. We would recommend Future Home Construction to anyone considering having work done to their house.
A S Builders
Rating: 5 out of 5
Extension Builder in Knebworth
We are a family run business in construction industry since 1990, initially started by my father and now his sons have joined the business and looking to revitalised the business through the use of up-to-date technology. We undertake all types of building work through our team of skilled labour from a small job up to New Build. Our most recent job was conversion of a detached property to 7 HMO's.
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Latest review:
Extensions- 29 Apr 2026
Heera, Jagthar and team was my first personal experience with builders. Let me tell you, it was a pleasure to have them do our porch and other renovations in the house. They are so courteous, hard working and provided a great service. Firstly, I had a comprehensively written quote breaking down all of the steps required. Heera then ensured to keep me in the loop of any developments/any changes of plan required, outlining the reasons why and options, making it easy to understand and work together to completion. Their finish was to a high quality and they would always go the extra step to ensure this. I highly recommend AS Builders for any job and will definitely use them again in the future, and would recommend to my friends and family also. If you are considering them, grab a free quote and go from there... That's what I did! Thank you AS Builders for our renovations!
Buildteam south ltd
No reviews yet
Extension Builder in Knebworth
We are a team with a lot of experience and we will help you make the best decision to reduce expenses and do a job well done.
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Mirma Construction Ltd
No reviews yet
Extension Builder in Knebworth
Since 2016, with a commitment to quality and customer satisfaction, we have specialized in a wide range of services tailored to meet your project needs. From comprehensive general Building Works to specialized services such as Piling Foundations, Drone Survey and Mapping, and Civil Engineering, we bring expertise and reliability to every endeavour. At Mirma Construction, our dedicated team of professionals combines years of experience with cutting-edge technology to deliver outstanding results. Whether you're envisioning a new construction project, enhancing existing structures with house extensions, or transforming landscapes with our Soft and Hard Landscaping services, we prioritize precision and attention to detail. Our mission is to exceed expectations by providing sustainable, efficient, and aesthetically pleasing solutions that stand the test of time. We take pride in our ability to deliver projects on schedule and within budget, ensuring seamless collaboration and transparent communication throughout. Explore how Mirma Construction can turn your vision into reality. Contact us today to discuss your next project and discover why we're a trusted partner in construction innovation.
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Terbuni building services
No reviews yet
Extension Builder in Knebworth
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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MBS Commercial construction Ltd
Rating: 5 out of 5
Extension Builder in Knebworth
We at MBS Commercial construction Ltd, are a self sufficient construction company who specialise in commercial and industrial industries including facilities management, we also cover domestic clients and factions. We are construction line gold, all operatives are NVQ qualified in their respective trades and all supervisors hold SMSTS and first aid training. We take pride in our work and stick by our core key company values of; 1. Reliability 2. Transparency 3. Cohesion 4. Sustainability With these at the helm of all our dealings, we strive to deliver projects on time, within budget, safely.
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Latest review:
Carpentry- 15 Sep 2024
MBS provided a great service. They were professional and pleasant, communicated well and did the work required.
ALL ABOUT CONSTRUCTION LTD
Rating: 5 out of 5
Extension Builder in Knebworth
My name is James I’m a carpenter joiner by trade but have been in construction for 22 years building extensions , loft conversions renovations etc . All work is quoted by me and carried out by me , or a helping hand on the day
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Latest review:
Joinery & Cabinet Making- 11 Jun 2026
The job went well.
bifold and sliding doors
No reviews yet
Extension Builder in Knebworth
We supply and install a wide range of Premium Glazing Solutions, bespoke to your requirements. Our products include Skylights, Sliding Doors, Bi-Folding Doors, French Doors and Aluminium Heritage Glazing. When working with us you may expect a friendly attitude combined with professionalism as well as an innovative approach towards your goals. Your final satisfaction is at paramount importance to us.
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Painter
No reviews yet
Extension Builder in Knebworth
I’m painter for 20 years
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Codenra ltd
No reviews yet
Extension Builder in Knebworth
I carry out general building work such as loft conversion, home extenstion , partition , plastering , laminate and tail.
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Nelson and Sons General Builders
No reviews yet
Extension Builder in Knebworth
We are general builders taking on extensions, bathrooms, kitchens. All trades covered. All our work is guaranteed and finished to a very high standard.
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Ava Constructions & Decors
Rating: 4.9 out of 5
Extension Builder in Knebworth
Ava Constructions & Decors Ltd is a UK-based construction and renovation company committed to delivering top-quality craftsmanship and reliable project management. We specialise in full refurbishments, extensions, bathroom and kitchen installations, and commercial fit-outs — always tailored to the client’s vision and delivered to the highest UK building standards. With a keen focus on transparency, timelines, and customer satisfaction, Ava Constructions has earned the trust of homeowners, investors, and developers alike. Punctuality and completion of work on time are a priority .Our team always respect the client wishes and work with them to achieve the best possible results to their satisfaction. Thank you in advance
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Latest review:
Extensions- 16 Apr 2026
I would not recommend this builder based on my experience. Instead of using crushed concrete they used soil to fill the house flooring for underfloor heating. 1 The project suffered from poor communication, repeated delays, and a lack of clarity around responsibilities. There were serious issues with the foundation works, which failed Building Control inspection and now require remedial engineering input before works can proceed. The site was also left incomplete and not in an acceptable condition. Despite substantial payments being made, key documentation, technical responses, and follow-through were lacking, leaving me to resolve major compliance and structural issues independently. My experience has resulted in delay, additional cost, and considerable stress. I would strongly advise others to ensure there is a detailed written contract, clear scope of works, and defined accountability
Fastway Constructions Limited
Rating: 5 out of 5
Extension Builder in Knebworth
At Fastway Constructions, we are dedicated to redefining the construction industry through sustainable practices and innovative solutions. Based in the United Kingdom, we pride ourselves on delivering exceptional quality and reliability across four key sectors: Residential Constructions, Commercial Constructions, Industrial Constructions, and Renovation & Remodelling Here at Fastway all of our employees are fully qualified, skilled and very experienced building contractors that have worked on hundreds of projects over the years resulting in 100% client satisfaction, full job completion on time, and always well within budget. All employees hold cscs cards for their relevant trades along with health and safety certificates and first aid for a competent safe worksite at all times. We are a building contractor with a professional approach to all our projects. We offer a seamless and multi-trade service, for all domestic projects from new builds, extensions, loft conversion, renovation to fully finished houses, all tailored to meet our clients’ specific requirements.
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Latest review:
Plumbing- 1 Aug 2025
Jitin did a good job in finding a solution to the leak in the washing machine drainage pipe. He used his experience in problem solving and fixed the issue. Thanks Jitin

3.6

Top rated Extension Builders

Our Extension Builders in Knebworth, 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 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.