Extension Builders in Harrow

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 3.8 (14 reviews)

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Some of our top rated extension builders in Harrow

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A-tech Building Services Ltd
Rating: 5 out of 5
Extension Builder in Harrow
We are a dynamic and profesional construction company, with a vast experience over the last decade and more, offering high quality build at a very competitive price always in mind with the latest legislation in safety and durability.
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Latest review:
Bathroom Fitting- 7 Nov 2025
Amazing work done by Antonel and his colleagues! The job was done to a very high quality standard and they were very thoughtful towards my needs always keeping good communication from the start of the process. Antonel promised me a very tight deadline of 5 days and he made sure this was met, always ensuring the job was done to a very high standard, I couldn’t have asked for more. Definitely someone I would recommend to anyone.
Pro Construction London Ltd
No reviews yet
Extension Builder in Harrow
Pro Construction London is a trusted London-based building company with over two decades of experience delivering high-quality renovations, refurbishments, and property maintenance. We pride ourselves on our professionalism, reliability, and attention to detail, ensuring every project is completed to the highest standard. From full property renovations and loft conversions to bespoke finishes and one-off repairs, we provide a seamless service from start to finish — clear communication, transparent pricing, and a tidy worksite every time. Our reputation is built on satisfied clients who return to us for future projects, knowing they can rely on a skilled and dedicated team to bring their ideas to life.
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LONGVIEW CONSTRUCTION LTD
No reviews yet
Extension Builder in Harrow
Longview Design & Build specialises in high-end architectural design in London. Our team take pleasure in understanding your vision and then guide you towards completion. We act as a one-stop-shop by providing you with all the tools you need to deliver success. Whether you’re looking to expand or refine your home with a loft conversion, rear or side extension, or a top to bottom refurbishment, we are the actual Design & Build construction company you are looking for.
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Cambridge group
No reviews yet
Extension Builder in Harrow
We are a trusted construction team with over 10 years of professional experience delivering high-quality building services across residential and commercial projects. Our goal is simple: to provide reliable workmanship, clear communication, and results that exceed expectations. Over the past decade, we have successfully completed a wide range of projects, including: • Home extensions & loft conversions • Full property refurbishments & renovations • Kitchen and bathroom installations • Carpentry and joinery work • Plastering, painting, decorating & tiling • Roofing, brickwork & structural modifications • Driveways, patios & landscaping • General maintenance and repairs Our portfolio includes dozens of completed projects, each finished with attention to detail, high-quality materials, and a commitment to customer satisfaction. We take pride in our craftsmanship and treat every job—big or small—with care and professionalism. Why choose us? • 10+ years of hands-on industry experience • Skilled, fully insured, and reliable team • Transparent quotes and regular updates • Clean, safe, and well-organised working practices • Strong portfolio and repeat customers We work closely with every client to understand their needs,
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Elite Constructions London
New on MyBuilder
Extension Builder in Harrow
Elite Construction London Ltd has been one of the top providers of building and remodeling services in London for more than ten years. Our goal is to offer high-quality services at affordable prices. We complete projects on schedule and within budget because we are dedicated to quality and client satisfaction.
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GRB Building and Home Improvements
Rating: 5 out of 5
Extension Builder in Harrow
At GRB Home Improvements we have over 15 Years experience in general building contracting including extensions, kitchen and bathroom refits, loft conversions, garden landscaping, patios and outbuildings, drainage and groundwork, drives and general building maintenance. We passionately believe in customer satisfaction and strive to ensure that our quality work is delivered on time, as per the agreed schedule, and that we come in on budget.
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Latest review:
Carpentry- 24 Jan 2021
George came to do up our hallway. He laid flooring and installed new spindles and a handrail on our stairs too. He did a wonderful job on the whole lot and we were very happy with him. We were awkward and changed our mind on the first laminate flooring that I had picked out online, he ripped it up and started again with the new flooring we picked and it was no hassle to him. George is a lovely fella, trustworthy and professional. Would highly recommend
JG
Rating: 5 out of 5
Extension Builder in Harrow
More than 15 years of experience in general building from groundwork’s to french polishing. Working for years with one of the biggest North London construction company as a carpenter supervisor. I feel content of my good work outcome. Would like to work weekends and evening times!
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Latest review:
Carpentry- 15 Jun 2026
Really great experience! Friendly, helpful and available at short notice. Did a great job. Super happy with everything. Would definitely hire again.
M & M ROOFING AND LOFTS LIMITED
Rating: 5 out of 5
Extension Builder in Harrow
We design for life, as well as style. That's why clients have trusted Mew developments for the past decade. We cover all aspects of the building trade quality is at the heart off everything we do. All of our tradesmen are passionate about creating solutions that are comfortable and useful. They are all individually trained to meet our exacting standards and, more importantly, yours.
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Latest review:
Extensions- 22 Oct 2018
Choosing MM builders was the best decision we could have made. Initial meetings: They took time to ensure they understand our work. They never complicated matters nor tried to hide things in any fine print and provided us with a estimated schedule and explained we would be kept up to date at all stages. Works: Their knowledge and work ethic is amazing and is reflected in their work. They gave us confidence and built trust very quickly. Always willing to go the extra mile and used their expertise to help us rectify issues or make suggestions in areas we would have never noticed ot thought of. Sam, Ross, Bill & Harry were so pleasant to have around the house. They were very conscious of the 3 young children in the house of which one has additional needs. They minimised disruption which is very difficult when doing major work in a areas and were always friendly and polite. We had no issues in having them inside our property which is very important when completing works taking just over 5 months. They work with specialist tradesman (tiler, plasterer, etc.) who are equally good at their trades. MM were very professional when it came to liasing with Building Control and made sure they were involved and visited at all key points. The aftercare we received was as good as we had received throughout the process. I have no hesitation in recommending MM for any building works. If I was to ever undertake any works in the future, it would be by them and only them.
Lasting Ltd
No reviews yet
Extension Builder in Harrow
At LASTING LTD, we specialise in high-quality residential construction and full property renovations across London and the surrounding areas. With years of experience and a strong reputation for reliability, we deliver projects with exceptional craftsmanship, clear communication, and attention to every detail. Our services include complete home refurbishments, loft conversions, kitchen and bathroom installations, structural works, flooring, plumbing, heating and electrical upgrades, and all types of internal finishing. Whether it’s a single room or a full house renovation, we provide honest advice, transparent pricing, and results built to last. We take pride in working cleanly, safely, and efficiently, ensuring every project is completed to the highest standards. Most of our clients come back to us again and again — because they trust our workmanship and appreciate our professional approach. If you’re looking for a reliable contractor who delivers quality without compromise, LASTING LTD is here to help bring your project to life.
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GSK
No reviews yet
Extension Builder in Harrow
Hard working methodical tradesperson with a proven track record of large and small projects.
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Highbury Builders
New on MyBuilder
Extension Builder in Harrow
We are a professional building works company specializing in high-quality residential and commercial construction. Our team delivers reliable workmanship, clear communication, and projects completed on time and to specification. We are committed to safety, compliance with regulations, and excellent customer service on every job.
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HCJ Building Services Limited
Rating: 5 out of 5
Extension Builder in Harrow
HCJ Building services Limited carry out all aspects of building services With over 25years experience within the building trade. extensions, loft conversions, Fitted kittens, bathrooms, flat roofing ( certified EPDM Installer ) electrical, plumbing, small maintenance repairs
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Latest review:
Extensions- 30 Jul 2019
Nathan from HCJ Building Service was excellent in all respects. He built an extension to our garage, which involved block-work, timber framing, roofing, cladding and installation of a door. When he visited the site to provide an estimate, he was enthusiastic and knowledgeable. His quote was competitive and he promptly answered a few questions we had about some of the technical details. When working on the project, he always arrived when he said he would and left the site tidy when he finished. My wife and I were impressed with how hard he worked, barely stopping to drink a coffee. When we interrupted him to find out how things were going he was happy to give us an update. He was always friendly and polite. He completed the project on time and left the site as he found it, removing all his waste. The work was done to a very high standard. We are really pleased with the result. This extension has freed up space in the garage for my woodworking hobby. We will definitely be coming back to Nathan to quote for future building projects. Now that I have my woodworking man cave my wife has started thinking about the kitchen...
Suri Design and Build Ltd
No reviews yet
Extension Builder in Harrow
We are a design and building company with a combined experience of over 25 years within the construction industry. We specialise in residential builds varying from new builds to extensions and internal renovations on existing buildings. We have also completed projects within the commerical and health sectors (such as GP surgeries). We have a Architectural department which can assist with all pre-construction works, from planning design through to building control submission and handover/completion. Client satisfaction is important to us!
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Rosa Construction
No reviews yet
Extension Builder in Harrow
From internal renovations that breathe new life into your space to building extensions that expand possibilities, and loft conversions that elevate residential and commercial structures—we have the experience and skill to handle it all.
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JC Group Property Sevices LTD
Rating: 5 out of 5
Extension Builder in Harrow
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.
Bright star construction Ltd.
No reviews yet
Extension Builder in Harrow
Hi there we are in construction industry 🏘️🏠from 13 years. We believe in quality and customer satisfaction. 🏗️
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3.8

Top rated Extension Builders

Our Extension Builders in Harrow, are rated 3.8 out of 5 based on 14 reviews from customers like you.

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What types of services are offered by local extension builders in Harrow?

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

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

What are the hourly rates of extension builders in Harrow?

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

Find extension builders in Harrow with MyBuilder

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

Step 2: Compare different extension builders in Harrow

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

Step 3: Hire Harrow extension builders with confidence

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

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

What to ask a Harrow extension builder before hiring?

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

An extension builder in Harrow 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 Harrow 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 Harrow?

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 Harrow 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 Harrow 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 Harrow

Can an extension builder in Harrow help with planning permission?

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

Many Harrow 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 Harrow help with materials and finishes?

Yes, most extension builders in Harrow 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.