Extension Builders in Harefield

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 3.9 (15 reviews)

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Some of our top rated extension builders in Harefield

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JC Group Property Sevices LTD
Rating: 5 out of 5
Extension Builder in Harefield
JC Group Ltd is a reliable and experienced building company offering bathroom installations, plumbing, home extensions, and general building works. With over 30 years of combined industry experience, we take pride in delivering high-quality workmanship, clear communication, and projects completed on time and within budget. We are committed to customer satisfaction and maintaining the highest standards on every job, no matter the size.
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Latest review:
We’re absolutely delighted with the extension and the overall experience from start to finish. The workmanship is to a very high standard, and everything was completed professionally and on schedule. Communication throughout the project was excellent, and we were kept informed at every stage. The team were reliable, tidy, and respectful of our home, and the finished extension has exceeded our expectations. We wouldn’t hesitate to recommend them to anyone looking for quality work and a stress-free build.
A&L Refurbishment UK
No reviews yet
Extension Builder in Harefield
Welcome to A&L Refurbishment UK! We specialize in transforming homes across Buckinghamshire, Hertfordshire, and London. From full refurbishments and renovations to extensions and conversions, our team brings your vision to life with quality craftsmanship and attention to detail. Whether you're looking to modernize your space or create more room for your family, A&L Refurbishment UK is here to make your dream home a reality.
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Aubrey Construction & Maintenance
New on MyBuilder
Extension Builder in Harefield
Welcome to Aubrey Construction and Maintenance, a reliable, family-run building business in Hemel Hempstead. Established in 1989 by Stuart Marum in honour of his late mother, Audrey, With decades of experience we take pride in delivering high quality workmanship and treat every project with care and professionalism no matter the size. Our commitment to detail and customer satisfaction has earned us the trust of homeowners and businesses alike. We continue to build that legacy with every job we undertake.
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PremierBuild Developments
No reviews yet
Extension Builder in Harefield
PremierBuild Developments LTD is an established building company based in Hemel Hempstead, Hertfordshire but also covering all surrounding counties & London.
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Primos Construction
No reviews yet
Extension Builder in Harefield
I have worked both in social housing and self employed. Most of my jobs as a sole trader has come from recommendations of people I've worked for. I am a stickler for time. In my business I aim to give the clients exactly what they've ask for and always always have the clients full satisfaction before leaving a job. Referral can be obtained before my employment
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Crystal Curb Cleaners
No reviews yet
Extension Builder in Harefield
I run Crystal Curb Cleaners, a professional driveway and exterior surface cleaning service based in London. As a one-person business, I take pride in delivering high-quality results with close attention to detail. Using powerful jet wash equipment, I help restore the look of driveways, patios, and pathways — always aiming for spotless, long-lasting results and satisfied customers.
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Express Boiler Exchange Company
Rating: 4.8 out of 5
Extension Builder in Harefield
Why choose us? 1. We bring your concept to life 2. A friendly, professional and reliable service 3. Ensure the journey is an enjoyable one 4. Acting responsibly and transparently. 5. You’ll be delighted with the result!
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Latest review:
Extensions- 28 Feb 2026
Poor workmanship , messy guys , roof leaking , walls not done properly , overall not good workmanship as have to redo many aspects of the kitchen extension I have to now replace the kitchen roof which was of poor quality , never employ Peter or Mariusz
visionpro cleaning and maintenance
No reviews yet
Extension Builder in Harefield
Our company is dedicated to becoming your contractor of choice no matter the service. We pursue excellence. Our dedicated and experienced team deliver quality in a timely fashion. we provide construction services and every job schedule is completed on a “Fast Track” basis with an emphasis on quality workmanship. Our pledge to excellence and customer satisfaction has led to repeat corporate with our clients and has been the cornerstone of our growth. We accentuate on establishing long-term relationships with our clients and this approach has helped us acquire and retain customers across different sectors and segments.
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landcraft improvements
Rating: 5 out of 5
Extension Builder in Harefield
Hi John here. Thank you for viewing my profile. I have been in the family business of landscaping and roofing construction work for many years gaining lots of experience form many types of projects. I offer competitive rates and aim to offer professional advice and carry out work to a high standard. Thank you again John.
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Latest review:
Roofing (Pitched)- 5 Mar 2024
John, an all round great person to deal with. Very helpful and did an excellent job. Would def recommend. :)
Build Four Four Limited
No reviews yet
Extension Builder in Harefield
Build Four Four is a full service building construction company dedicated to building and improving residential and commercial structures according to client needs and desires. We specialise in transforming your home into what you always wanted. Be it a loft conversion, extension or a new build from scratch. You can be rest assured that at BFF, quality, precision and excellence comes first. Based in Hertfordshire but also covering London and Essex, the team at BFF is ready to give your space whatever updates it requires. Just give us a call or enquire online today and we’ll get back to you as soon as we can with a quote.
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CJP LANDSCAPES
No reviews yet
Extension Builder in Harefield
At CJP Design and Build we cover all aspects of building and landscaping. We are a family run business that is committed to quality. We are fully insured and there is no job too big or too small. We like to work with clients to gain as much possible for a budget that suits. Reputation matters and we thrive from your reviews. All the best!
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Perry earth works
No reviews yet
Extension Builder in Harefield
No job to small or to big from Clearing to foundations we can do it. The customer comes first always and we value making the customer happy. The main part of our work is is excavations and foundation concrete works but we’re always happy for a challenge and if a customer asks for something a bit different to what we usually do I’m sure we can find a way to make it work.
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JBP Developments Ltd
No reviews yet
Extension Builder in Harefield
1. Surveys - Offering drone and Matterport surveys for planning applications and marketing purposes 2. Architectural Services - Providing drawings for pre-app and planning submissions. 3. Project Management - Managing multiple consultants, sub-contractors, and statutory authorities at any stage of the construction process. 4. Design and Build
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MO Construction
No reviews yet
Extension Builder in Harefield
SUITE 504, CUMBERLAND HOUSE, 80 SCRUBS LANE, LONDON, NW10 6RE AMO Construction Group Ltd is a lean, high-performance construction company delivering end-to-end building solutions with zero compromise on quality, safety, or timelines. With over 15 years of industry experience, we operate with a founder-led mindset, tight operational control, and a culture built around precision execution. We specialise in residential and commercial construction, structural works, refurbishments, and full-scale project delivery. Our approach goes beyond building — we orchestrate projects from concept to completion. Every job benefits from senior-level oversight, fast decision-making, clear communication, and a delivery pace that consistently outperforms traditional contractors. Clients work with us because we reduce friction, protect budgets, and deliver measurable value. We combine a small, agile team with big-project capability, maintaining relentless standards of workmanship and accountability on every site. Small team. Big output. That’s the AMO Construction standard
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Armando
No reviews yet
Extension Builder in Harefield
I'm carpenter I been doing this job for more than 10 years.
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T De Maio Brickwork services
Rating: 5 out of 5
Extension Builder in Harefield
Our aim is simple, Obtain repeat business and recommendations by providing customer focused services, producing high quality work on time and within budget. Please take a look at my photo gallery of the work myself and the team can produce, our work speaks for itself👍 Kind regards Tony De Maio
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Latest review:
Bricklaying- 28 Jul 2019
With me having no previous experience and knowledge. Toni was helpful and I felt that what ever I asked Toni to do, he could provide. I trusted him completely with what I asked, and he was the best quote by far. Toni helped with where to purchase what was needed and was clear and transparent throughout. I am even thinking of having more work done now I know what can be produce.

3.9

Top rated Extension Builders

Our Extension Builders in Harefield, are rated 3.9 out of 5 based on 15 reviews from customers like you.

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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 Harefield?

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

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

What are the hourly rates of extension builders in Harefield?

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

Find extension builders in Harefield with MyBuilder

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

Step 2: Compare different extension builders in Harefield

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

Step 3: Hire Harefield extension builders with confidence

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

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

What to ask a Harefield extension builder before hiring?

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

An extension builder in Harefield 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 Harefield 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 Harefield?

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 Harefield 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 Harefield 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 Harefield

Can an extension builder in Harefield help with planning permission?

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

Many Harefield 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 Harefield help with materials and finishes?

Yes, most extension builders in Harefield 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.