Extension Builders in Knebworth

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

1532 Results

Sort by:

FSB Company (UK) LTD
Rating: 5 out of 5
Extension Builder in Knebworth
FSB is a well-organized contracting company with a team experienced in large-scale development projects with leading UK construction companies. Based primarily in London, we offer a variety of self delivered services, including complete extensions, and conversions, small works, structural alterations, steel work installations, ground work (foundations, drainage, concrete sub and superstructures), hard landscaping and paving and soft landscaping. We manage our sites carefully and have a digital site management tool kit. Our fully managed service connects skilled tradespeople with experienced construction management directly ensuring attention to detail that begins with our Contractors Proposals and continues through to practical completion and aftercare.
Get in touch
Latest review:
Extensions- 17 Nov 2025
Freddie, Kaz and Dan are a great team. I felt they were friendly and professional throughout. Any slight niggles were discussed and solutions found, quickly and professionally. They were respectful and went out of their way to get on with all the neighbours. Over all I would say they are a team of very nice people, who care about what they do and take pride in achieving the result their clients are after.
Gabhru brickwork
No reviews yet
Extension Builder in Knebworth
Hi, I’m Yatin, a skilled and reliable bricklayer with years of experience in all types of brickwork — from garden walls and extensions to repairs, repointing, and decorative features. I take pride in delivering high-quality workmanship, clean finishes, and friendly, professional service on every job — big or small.
Get in touch
Darren Coote Builders
Rating: 5 out of 5
Extension Builder in Knebworth
I have worked in construction for 30 years. I am a reliable, conscientious, trustworthy and happy person. I have City & Guilds in Brickwork, of which I did my apprenticeship. I specialise in driveways, patios, extensions, brickwork, new builds and much more. I only do 1 job at a time from start to finish. Thank you.
Get in touch
Latest review:
Extensions- 24 Apr 2019
Darren was on site every day without fail. His work was 1st class. He knows his job and is very experienced. He was able to give us a start and finish date and he kept to those dates. He cleared and cleaned the site every day. He was an absolute joy to be around and went the extra mile to ensure we were pleased with his work. I would not hesitate to recommend him. His brickwork is a pleasure to look at and both the extensions he built - a rear extension with bi-fold doors, and a side extension (the garage) both look as if they've always been there. Craftsmanship at its best. He knows the building regs required, his standards are 100% good. Darren's prices are extremely competitive, he's no rip-off merchant.
Mailm limited
No reviews yet
Extension Builder in Knebworth
We provide complete building solutions on both Residential and Commercial sites and smaller domestic builds. Our valuable experience is shown in all aspects of our work.
Get in touch
Peter The Builder
Rating: 5 out of 5
Extension Builder in Knebworth
Hello. My name is Peter. I am a builder based in Slough. I used to run my own business back in Poland for 10 years. I do all sorts of work like painting, decorating, tiling, flooring, kitchens, bathrooms, plastering, bricklaying, driveways, gardening, fencing, paving and patio slabs , turfing . I am respectful and keen to get the job done. Thank you so much for your time , Kind regards.
Get in touch
Latest review:
Fencing- 9 Jun 2026
Recommended - competitive price and completed as agreed.
Belvedere Electrical Ltd
Rating: 5 out of 5
Extension Builder in Knebworth
Belvedere Electrical Ltd is my new business, after working employed for many years. I have now decided to complete works for myself to the highest of standard, with customer satisfaction being my top priority.
Get in touch
Latest review:
Electrical- 26 Mar 2023
Very efficient and clean work
Fisher construction ltd
No reviews yet
Extension Builder in Knebworth
We do large construction work, new builds large extension and swimming pools.
Get in touch
Beacham Architects
No reviews yet
Extension Builder in Knebworth
We help home owners extend and improve their homes to suit their needs and dreams. We are design-led and specialise in extensions, loft conversions and basements all around London with budgets of £50k-£400k. Good design improves lives and adds value, just ask our clients. Our extended team includes expert ARB registered architects, interior designers, structural engineers and party wall surveyors. Contact Mike for a tailored and customisable service quotation, the first consultation is free!
Get in touch
DEEP GROUNDWORKS AND CONSTRUCTION LTD
No reviews yet
Extension Builder in Knebworth
At Deep Groundworks and construction ltd , we specialize in comprehensive groundworks and construction services tailored to meet the unique needs of each project. With a dedicated team of skilled professionals and years of industry experience, we pride ourselves on delivering quality workmanship and exceptional customer service. From site preparation and excavation to drainage solutions and foundation work, we handle every aspect of construction with precision and care. Our commitment to safety and sustainability ensures that we complete projects efficiently while minimizing environmental impact. Whether you're a homeowner embarking on a renovation, a contractor managing a large development, or a business seeking reliable construction solutions, Deep Groundworks and construction ltd is here to turn your vision into reality. Let us build your future together!
Get in touch
AV General Construction
No reviews yet
Extension Builder in Knebworth
We are a construction company run by a Site Manager with 15 years of experience on the tools and in the office. We do things properly by using specialist tradespeople for every part of the job—so you get an expert roofer for your roof and a professional decorator for your walls. From kitchens to rendering, we manage the whole project for you, ensuring every trade delivers high-quality work that’s built to last. Simple, reliable, and expert service across the board.
Get in touch
24 Hour Landlord Solutions Ltd
No reviews yet
Extension Builder in Knebworth
24 Hour Landlord Solutions, provide IT and electrical, plumbing, gas, fire alarms and all sorts of commercial and domestic services these include PAT testing and etc…
Get in touch
MRC building projects ltd
No reviews yet
Extension Builder in Knebworth
Hi, I am iqbal singh. We are a team of 4 and very professional. Very keen to build our customers a quality home.
Get in touch
Primeworks Construction Ltd
No reviews yet
Extension Builder in Knebworth
About Us: Welcome to Prime Works Constructions! We are a dedicated and experienced residential construction company specializing in high-quality new builds, renovations, and extensions. With a passion for excellence and a commitment to customer satisfaction, we bring your dream home to life with precision and care. Our Services: * New Builds: From initial planning to the final finishing touches, we manage every aspect of constructing your new home. Our team ensures a seamless and stress-free experience, delivering on time and within budget. * Renovations: Whether it's a complete home makeover or specific room upgrades, we transform your existing space into a modern, functional, and aesthetically pleasing environment. * Extensions: Need more space? Our expertly designed extensions blend seamlessly with your existing structure, adding value and comfort to your home. * Custom Projects: Have a unique vision? We specialize in bespoke construction projects tailored to meet your specific needs and preferences.
Get in touch
POLISH DECORATING SERVICES LTD
Rating: 4.9 out of 5
Extension Builder in Knebworth
We are not the cheapest but we are Master Builders experienced in all aspects of building works including bespoke services. Dedicated team of craftsmen always deliver jobs to the highest standards. We provide full certification for any gas or electrical works. City&Guilds- N.V.Q., P.A.S.M.A. and I.P.A.F. Over 15 years of experience in the UK.
Get in touch
Latest review:
Extensions- 11 May 2018
After a rogue builder left me with 18 (eighteen) structural issues. Lez and his crew came in transformed my failed extension into a masterpiece. All aspects of the job was done to the highest quality and utmost care and attention to detail was shown to building control needs. They cleaned up after every day and made sure the house was habitable, as I had to live there. Every aspect of the build, from the carpentry, plastering and tiling was first class and their recommend electrician and plumbers were from the same stock. Total professionals. My only regret is that I did not use this builder the first time. The prices were reasonable and even building control had good word to say about their work. Thanks Lez
Delta Build Services
No reviews yet
Extension Builder in Knebworth
collectively have experience of about 10 years, done several complete refurbishments, single and double story extensions, loft conversions. have done a newbuild warehouse from scratch to complete. have good experience of electric, plumbing, and joinery. qualifications for electrics are part P of building regs., 17th edition and Inspection & testing. Electric certificates will be provided through NICEIC.
Get in touch
Top celine ltd
No reviews yet
Extension Builder in Knebworth
I work professionally and quickly, my clients are happy with the work I do! I do plastering, painting, parquet, thermal insulation on the outside!
Get in touch

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.