Extension Builders in Harpenden

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 3.7 (13 reviews)

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

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 Harpenden

1768 Results

Sort by:

T.M Construction.ltd
Rating: 5 out of 5
Extension Builder in Harpenden
TM Construction.ltd, established in 2007, is a trusted building company specialising in extensions, loft conversion,refurbishments, and general construction projects. With over 15 years of experience, the company is known for its high-quality workmanship, reliability, and customer-focused approach. From groundwork and structural works to finishing touches, TM Construction delivers complete building solutions on time and within budget.
Get in touch
Latest review:
Roofing (Pitched)- 6 Mar 2026
Thomas was a pleasure to work with. Polite and accommodating. Would definitely hire him again.
MSG DESIGN LTD
Rating: 5 out of 5
Extension Builder in Harpenden
Hello I am Simion, the proud owner of Msg Design Ltd , A little about us With many happy and returning customers over the last 7 years, you can be sure of being well looked after. Our aim is to provide a stress free project, delivered in a manner that I am confident will exceed your expectations. I work with a small team of trusted colleagues, who communicate and work together well. Our customers are accustomed the outstanding quality of projects we complete, by sourcing quality materials with experienced installers we create truly bespoke masterpieces lasting our customers many years. 2 year guarantees are included as standard on all completed work. Availability We are always contactable via phone throughout the week, including evenings and weekends. If for any reason you are unable to contact us, please send a text message or email. Thank you for taking the time to consider our company’s profile, I look forward to hearing from you. Msg Design Ltd
Get in touch
Latest review:
Carpentry- 7 Jun 2026
Top carpenter. Will definitely be using again. Neat and great craftmanship.
TJD Driveways & Landscape
No reviews yet
Extension Builder in Harpenden
My name is Tony. I'm a qualified bricklayer who has experience in New builds, extensions, footings, groundworks. I also specialise in driveways, patios and all aspects of landscapeing . I've always been tought to do the job right first time. I'm proud to say i produce exceptional work and standards. Clarified by every customer and building official I've worked with.
Get in touch
coppertree construction ltd
No reviews yet
Extension Builder in Harpenden
Coppertree Construction Ltd. we are a professional building company offering reliable construction solutions. we focus on quality workmanship, clear communication and results you can depend on. we specialise in single story extensions and house refurbishments.
Get in touch
Ceca Developments LTD
Rating: 5 out of 5
Extension Builder in Harpenden
Hael Construction Ltd, a proud member of the Federation of master builders, is a trusted construction company based in North London, delivering high-quality building services across the region. We specialise in new builds, extensions, loft conversions, renovations, groundworks, electrical installations, and plumbing. With a skilled team of qualified tradespeople and experienced project managers, we provide a complete service from design to completion. Our focus is on quality workmanship, transparent communication, and delivering projects on time and within budget.
Get in touch
Latest review:
Extensions- 23 May 2022
Ceca Developments have done an outstanding work on our side and rear extension project, and we would definitely recommend this company. Firstly, they have offered a really competitive quote for the work and have been very transparent and detailed in regards to how long it will take to complete the project. Sebastjan has been a pleasure to deal with and was very helpful during the project, providing honest and useful recommendations and being available every time we needed anything. All the work has been completed to a very high standard and to the agreed timelines. We did not have to worry about anything during the whole project, which made this a very pleasant experience.
Daniel Gagea
Rating: 5 out of 5
Extension Builder in Harpenden
We are onest builders, quick and reliable jobs, new on my builder but with lots of experience on the trade, looking for work, we do all kind of refurbish jobs, decorating, carpentry, basic plumbing and electric, new bathrooms or kitchens, back or loft extensions ,landscaping and much more We offer guarantee for our work. Everything seen on the pictures is 100% our work and we have loads of other pictures
Get in touch
Latest review:
Daniel quoted comprehensively and clearly for both jobs that I needed, building an extension and a raised patio at the end of the garden. He worked extremely hard and diligently every day. Also he would summarise what he would do next and we discussed any changes etc and which tiles or render I preferred. I am very happy with both the patio and extension and Daniel finished everything off to an excellent standard and went above and beyond the quote. I would not hesitate to use him again and recommend him highly.
DJP BUILDING SERVICES
No reviews yet
Extension Builder in Harpenden
General building company specialising in groundwork, brickwork and plastering.
Get in touch
Gazmend
No reviews yet
Extension Builder in Harpenden
Hi my name is Gaz, I do extensions from start to finish, loft conversion, Garden refurbishment and patio, Best prices around guaranteed Don’t hesitate to give me a call
Get in touch
Jay Truslove
No reviews yet
Extension Builder in Harpenden
Been roofing for 20+ years and went into building about 15 years ago. All aspects of work undertaken.
Get in touch
Jeffrey Worts
No reviews yet
Extension Builder in Harpenden
I am a reliable trustworthy local builder with a vast range of experience built up over 40 years in the industry. Able to help you in designing and fulfilling your project.
Get in touch
Botnari Construction
Rating: 5 out of 5
Extension Builder in Harpenden
Botnari Construction. Every project is unique to every homeowner with small details having significant importance. What matters to our clients is what matters to us and these are the problems that we like to solve. We specialise in all Construction works with many years being in the industry, making sure we deliver a fast, efficient and well-organised project at its best.
Get in touch
Latest review:
Botnari Construction recently completed a project for me and I was extremely impressed with the way they work. From the quality completed to great time management I was very happy with the works carried out. Will definitely be using in the future. 10/10
Jr general building
Rating: 5 out of 5
Extension Builder in Harpenden
Professional Builders JR General Building Ltd is a fully-insured, limited company with a heritage spanning three generations. We excel in delivering comprehensive building services, from foundational work to chimney construction. Our specialised departments are staffed by fully-qualified professionals, ensuring all your requirements are met to the highest standards. As an SMAS-accredited organisation, we take safety seriously. Every member of our team holds a CSCS registration, guaranteeing not just an exceptional finished project, but also a commitment to conducting work in a safe and secure manner. 20+ years experience 500+ projects 100% customer satisfaction
Get in touch
Latest review:
Driveways (Paved & Loose)- 23 Oct 2023
Very pleased with the repair work on my block paved driveway. Jamie and Lee were very professional and helpful. Job was completed quickly and at a reasonable price. I would use them again!
Mbalau Construction LTD
Rating: 5 out of 5
Extension Builder in Harpenden
Builder with 20 years of experience . I provide a wide range of building services such as: loft conversion, extensions,bathroom refurbishment,house refurbishment , plumbing and electric etc . I have the tools,knowledge and team to build a house from start to finish . I can provide references and pictures of previous work upon request .
Get in touch
Latest review:
Complete refurbishment of 2 bed 1100 sq ft flat. Including removal internal walls Ripping out and renovating 2 bathrooms. Involving new layout replumbng and relocation of #electrics. Tileing Preparing and laying wood flooring throughout. Fitting shelving and book case. The work over 2 months involved all building skills. Throughout Marcel and his highly skilled crew were efficient clean and resourceful. I would highly recommend for all building and decoration work.
Z&S Builders Ltd
Rating: 4.7 out of 5
Extension Builder in Harpenden
Z&S builders are an equal opportunities employer. We are diverse workforce made up of hardworking, experienced people . We provide our customers the best service. Our quality of work is higher and we never compromise with the quality.
Get in touch
Latest review:
Painting & Decorating- 16 Sep 2021
Don’t trust them they lying in every bit we send them back on the first day of the work
Roman Way
No reviews yet
Extension Builder in Harpenden
Hard working builder with years of experience.
Get in touch
Parker
No reviews yet
Extension Builder in Harpenden
Bricklayer by trade . But have been given the chance to learn the whole game from footings to ridge tile , back all the way down to finishing the landscaping out to the gates . Know the game very well . 25 years learnt straight from school
Get in touch

3.7

Top rated Extension Builders

Our Extension Builders in Harpenden, are rated 3.7 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 Harpenden?

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

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

What are the hourly rates of extension builders in Harpenden?

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

Find extension builders in Harpenden with MyBuilder

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

Step 2: Compare different extension builders in Harpenden

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

Step 3: Hire Harpenden extension builders with confidence

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

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

What to ask a Harpenden extension builder before hiring?

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

An extension builder in Harpenden 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 Harpenden 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 Harpenden?

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 Harpenden 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 Harpenden 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 Harpenden

Can an extension builder in Harpenden help with planning permission?

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

Many Harpenden 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 Harpenden help with materials and finishes?

Yes, most extension builders in Harpenden 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.