Extension builders in Knebworth

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4.7 (13 reviews)

Easily find verified Knebworth Extension Builders. Just post your job to get quotes from MyBuilder's Extension Builders in Knebworth.

Select a service

How it works

Post your job for free

Tell us about your job, and we’ll alert suitable tradespeople in your area. It’s simple and free.

Tradespeople respond

Once your job is posted, you’ll get responses from interested tradespeople through the website.

Review profiles and choose

Browse profiles, work history, and feedback, then choose who you wish to share your details with.

Some of our top rated extension builders in Knebworth

1627 Results

Sort by:

Ervis
Rating: 5 out of 5
Extension Builder in Knebworth
I’m a reliable and skilled handyman with several years of experience in the construction industry. I specialise in carpentry, joinery, hard flooring, and a wide range of general home repairs and maintenance. I take pride in delivering high-quality workmanship, completing every job to a professional standard and exactly to my clients’ requirements. I’m always happy to offer honest advice and practical solutions to help you get the best results for your project. Whether it’s assembling furniture, fitting doors, installing flooring, repairing woodwork, or tackling general handyman tasks, I’m committed to providing a dependable, friendly, and competitively priced service. Customer satisfaction is my top priority, and I always leave every job clean, tidy, and completed to the highest standard.
Get in touch
Latest review:
Handyman- 20 Sep 2026
Ervis has just finished constructing a Dunster House 6x4 shed in my garden. His communication was excellent, as was his punctuality. I was really impressed with his work ethic and his craftsmanship - as it was not a simple shed to construct. Really happy with the end product. Would 100% use again for any jobs on my house! Thanks Ervis!
Craft Property Solutions Ltd
Rating: 5 out of 5
Extension Builder in Knebworth
Craft Property Solutions is a leading property refurbishment and remodelling company that specialises in both the residential and commercial sectors. Our team of experts can carry out interior alterations, extensions, loft extensions, and office fit-outs. We also have a specialist tiling division that can handle all your tiling needs.
Get in touch
Latest review:
Bathroom replacement. Team were very efficient and made additional effort to accommodate the tenants. Communication was great throughout.
James Harris
Rating: 5 out of 5
Extension Builder in Knebworth
We are a small team that has been in the industry for 28 years, working on large and small domestic and commercial contracts . We cover all domestic building works from extensions ,loft conversions and renovations and we have a large portfolio of our works and client feed back . We pride ourselves on -quality work - in-depth knowledge of the building industry ,modern building practices and building regulations Ensuring your project meets the highest of standards
Get in touch
Latest review:
Extensions- 13 Jul 2026
James did a brilliant job on our kitchen renovation and extension. He was on site every single day, which made a huge difference to how smoothly the project ran. Communication was excellent throughout: he explained what was happening at each stage, flagged issues before they became problems, and was always straightforward to reach. What stood out most was how honest and trustworthy he was. No corners cut, no unnecessary upselling, just solid, reliable work from start to finish. The fitting itself was done to a high standard and the whole extension came together exactly as we’d hoped. Would recommend James without hesitation and wouldn’t hesitate to use him again.
Newell groundworks ltd
Rating: 5 out of 5
Extension Builder in Knebworth
A small family run business with over 20 years experience.
Get in touch
Latest review:
Groundwork & Foundations- 15 Oct 2025
Stuart was great to work with. Knowledgeable, hardworking and committed to doing a great job. We will be using his services again in the future.
Design A View Limited
Rating: 5 out of 5
Extension Builder in Knebworth
At Design A View we specialise in window and door installations, porch builds, conversions, structural alterations for new bifolds or sliders. We are Fensa and CPA registered offering insurance backed guarantee’s With 30 years experience in the industry we offer a wide range of quality products and a finish of work that sets us apart, creating new openings and improving existing. Products: We are proud to be an approved Origin supplier Also Cortizo Aluminium doors, sliding and bifold Standard U-Pvc, flush casement windows, vertical sliding windows and doors Wooden vertical sash, casements and doors We look forward to working with you
Get in touch
Latest review:
Extensions- 21 Oct 2025
Quick, honest pricing and great advice to minimise the impact rather than trying to inflate it like other traders do. I would highly recommend Lee and his team.
TCBUILDERS LTD
Rating: 5 out of 5
Extension Builder in Knebworth
I have over 20 years experience in carpentry and joinery, building and refurbishment works, kitchens and bathroom installation, design and build, landscaping and garden rooms. I have worked in construction from an apprentice carpenter to site management on new builds and residential works. Delivering quality is my aim no matter size or cost.
Get in touch
Latest review:
Bricklaying- 26 Nov 2021
The guys did an excellent job re-laying the coping stones - responded promptly and came to price up quickly, friendly and professional! Wall looks so much better.
DRJ Homeimprovements
Rating: 4.9 out of 5
Extension Builder in Knebworth
DRJ Home Improvements Ltd provides reliable and trustworthy service completed to a high level of standards because I believe you don't need to move, Just improve. I have got 20 years experience in the building trade satisfying clients. We are a team that will get your job done from start to completion.
Get in touch
Latest review:
Extensions- 31 Jul 2026
Dan, is an immense organiser, everything on site runs like clockwork. He’s neat and tidy, and cleans up daily. The tradesmen he hires are top notch and all love working with him. The job is well thought out from start to finish and he considers your needs throughout as well. For example we had a kitchen extension and he made sure at the end of each day we had running water and a hob! Very courteous. He keeps you well informed of what’s going on day to day, and presents exemplary work before the building inspector. Lee, his right hand man, is equally as thorough and they make a wonderful team. Every aspect of the build is well thought out. All of the materials arrive on time. Tradesmen are booked in advance and are always punctual. Our build ran like clockwork. We had progress chats every evening on the phone and the plan for the days ahead. Dan likes to keep you well informed of everything going on, and will give expert advice on any snags throughout. Would 100% recommend him.
Nick's Authentic Carpentry and Building
Rating: 5 out of 5
Extension Builder in Knebworth
We're a new company but have the experience and knowledge of any other company.We're professional, organised, and give our customers what they expect and deserve. Being proud workers and undertaking everything thats thrown at us, Our focus is the job we're on!
Get in touch
Latest review:
Carpentry- 31 Aug 2011
Highly recommended and friendly carpenter. The job was done within 24 hours of posting. He gave me a time and even called to say he was on his way. Price was very reasonable indeed. Job was done to my total satisfaction with 100% professionalism. I am certainly going to have Nick do any other jobs that arise. He clearly has a vast knowledge of a whole range of trades and skills apart from carpentry. It is so nice to have found such an able tradesman who can be trusted to do a great job.
D & C Kitchen Installations Limited
Rating: 5 out of 5
Extension Builder in Knebworth
We undertake full or part refurbishment or existing and new build works. We specialise in kitchen installations and building alterations. We can provide a full team of specialist to complete all building works from design to completion. We are a registered Ltd company, fully insured and members of BiKBBi and only use registered contractors.
Get in touch
Latest review:
Ciaran ripped out my old kitchen and installed a new one and at the same time adding a door to the garage. Ciaran’s workmanship is second to none, his eye for detail and knowledge is awesome. Ciaran is a true very polite and all together a sound tradesmen. Always here early and put in the hours. I would absolutely recommend Ciaran and his work it was well worth the wait. Thank you.
LandMarx Ltd
Rating: 5 out of 5
Extension Builder in Knebworth
Small friendly family run business with over 30 years construction and refurbishment experience. We offer all types of building services wether it is a small maintenance job to a new build . We work on commercial and residential buildings. We also provide project management for self-builders who want to keep to a budget and have someone with the expertise to guide them through the building process from conception to finish. We are CHAS accredited and DBS checked.
Get in touch
Latest review:
Keith has helped design and fit our kitchen/utility room. Has re felted the flat roof on my garage and extension. He is currently fitting all my doors, skirtings and door linings. He boarded up and plastered doors where we have removed cupboards and larders. Great job, very reliable and multi trade so i would highly recommend him. I'm an electrician so work with a lot of builders so i can recognise a good workman.
Integrated Homes Ltd
Rating: 5 out of 5
Extension Builder in Knebworth
Integrated Homes Ltd are a family run construction founded in 1997. We specialise in extensions, conversions and renovations. We also work with architects so are able to assist with the design stage of your build.
Get in touch
Latest review:
We recently completed a large renovation which included extending our kitchen at the rear of the property, changing levels in the garden and converting our loft with an additional bedroom and en-suite. Ben, Steve and the rest of their team were amazing throughout. We had difficulty moving out of the property as our short term let fell through but the team worked tirelessly to enable us to ‘live in’ whilst much of the build was going on (which I know wasn’t ideal!) I highly recommend Integrated Homes as Ben and Steve were so knowledgeable, considerate and professional in their work.
ABL Building & plumbing solutions
Rating: 5 out of 5
Extension Builder in Knebworth
We are a family run business, take pride in our work we carry out. We cover all aspects of building works from hanging a door to a complete new build house.
Get in touch
Latest review:
Plumbing- 28 Jun 2023
Alan was a total professional, clean and tidy, fabulous job, will use him again and recommend him to everyone I know. Top professional.
Leni Muca Builder
Rating: 5 out of 5
Extension Builder in Knebworth
My name is Leni I have 8 years experience on home improvements. Kitchens, Bathrooms, tiling, flooring, carpentry, electrical, plumbing, handyman. I guarantee a professional work to be done. My priority is to make clients happy with the work I do. I promise you will not be disappointed from Leni Muca Builder. Thank you.
Get in touch
Latest review:
Bathroom Fitting- 3 Dec 2020
10/10, would recommend to anyone. High quality of work, very helpful and punctual.
JMP Consulting Engineers Ltd
Rating: 5 out of 5
Extension Builder in Knebworth
With nearly 30 years of experience, JMP Contractors & Engineers is a trusted, family-run company delivering high-quality construction across the UK. We specialise in bespoke garden rooms, combining timber frame expertise with modern design to create stylish, durable, and fully functional outdoor spaces. Whether you're after a home office, gym, guest suite, or creative retreat, our custom-built garden studios are designed around your needs—built to last and add real value to your property. We also offer loft conversions, extensions, renovations, and full structural engineering services. Every project is delivered with care, clear communication, and a commitment to excellence. You dream it. We build it.
Get in touch
Latest review:
Extensions- 21 Dec 2023
Great job and great after service. Highly recommended. Thank you team! Will use again :)
BARNETTS BESPOKE
Rating: 5 out of 5
Extension Builder in Knebworth
At Barnetts-bespoke we specialise in high quality custom carpentry and building solutions tailored to your unique needs, proudly serving all areas of Hertfordshire and London we offer high end craftsmanship for a wide range of projects including bespoke wardrobes, kitchens, bespoke storage solutions, and complete renovations Our complete list of services are listed below *kitchens *bathrooms *extensions * bespoke wardrobes/cabinetry *roofing *flooring * summerhouses * Returbishments * new build
Get in touch
Latest review:
Carpentry- 11 May 2020
Charlie was absolutely brilliant, fist class tradesmen with extremely high standards Will definitely use and recomend to others
AJK Building
Rating: 5 out of 5
Extension Builder in Knebworth
AJK BUILDING is a trusted name in the construction industry, delivering high-quality building solutions with a commitment to excellence, integrity, and innovation. With over 16 years of experience, we specialize in providing comprehensive construction services that include residential, commercial, and industrial projects. Our team consists of highly skilled professionals who work collaboratively to bring each project to life with precision and care. From initial planning and design to final execution, we ensure every phase is handled with professionalism, transparency, and strict adherence to timelines and budgets. At AJK BUILDING, safety, sustainability, and client satisfaction are at the core of everything we do. Whether it’s a small renovation or a large-scale development, we are dedicated to building spaces that last and relationships that grow.
Get in touch
Latest review:
Decking- 3 Jun 2026
Anthony did a great job from start to finish. Having had a few quotes, some cheaper, I decided to hire Anthony for the job as his quote was fair, thorough and clear about the process, materials, time needed, I did not get this assurance from some of the cheaper quotes. He listened carefully to what I was looking to do and make some good suggestions to help achieve the look I wanted for my decking. Communication was clear at all times during the job. Once the job started, Anthony was punctual each day, organised and ensured the site was kept clean at all times. I am very happy with the decking and standard of work achieved. I would highly recommend Anthony and AJK Building and would definitely hire him again for any future jobs.

4.7

Top rated Extension Builders

Our Extension Builders in Knebworth, are rated 4.7 out of 5 based on 13 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.