Extension Builders in Harrow, Greater London

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 Harrow, Greater London

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City Building and Roofing Ltd
Rating: 4.9 out of 5
Extension Builder in Harrow, Greater London
City Building and Roofing Ltd provides professional roofing, refurbishment and building services across London and Surrey. Our services include roof repairs, new roofs, flat roofing, GRP roofing, roof refurbishment, guttering, fascias and soffits, chimney work, damp proofing, brickwork and full property refurbishment. We work with homeowners, landlords and commercial clients, delivering reliable workmanship, honest advice and free no obligation quotes.
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Latest review:
Damp Proofing- 26 Mar 2022
Good,timely and clean workers. Worked hard and efficiently with clear explanations. Very satisfied with the finish.
SIXTHART LTD
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
We are an Architectural and Interior Design Studio. We effective planning and technical drawing services. Our Services - Site Survey -All Drawings with Cad Software (Demolish/Proposed) - Draft Planning - Pre Advice Planning - New Build Design - Loft Conversion - Home Extensions - 3D Visulation -Kitchen &Bathroom design projects - Preparation and submission of planning applications - Hourly\Daily Based CAD Services - 3D Modelling (Internal & External Visualisation) -Member of TAG (Traditional Architecture Group) -Bachelor’s Architectural Design Practice -NAAB -TMMOB
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Latest review:
Extensions- 16 Sep 2024
Erhan was excellent. He followed my project from start to finish and kept me updated throughout. Here to the next project!
Danut
No reviews yet
Extension Builder in Harrow, Greater London
Brick work , roofing, tiles roof flat roof, patio
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CHL IMPROVEMENTS LTD
No reviews yet
Extension Builder in Harrow, Greater London
North London based 10 years of experience
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DBMP LTD
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
Our focus is to provide customers with expertise, quality workmanship, and a high level of communication throughout the process. We pride ourselves to offer a high level of customer satisfaction, this has been our main driving force over the years. We are fully insured.
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Latest review:
Insulation- 28 Feb 2023
A Great British company who I will call first for all future work. I have multiple properties and seen many traders. Workmen never give compliments to others but two of my regulars were there and both told me his work/team were very good. DBMP treat the work like it is their own property. Good quality work, neat, thoughtful of other workmen/tenants, took all the rubbish away. No mean feat as he replaced skirting & floorboards, installed rock wool and rubber mats, re-fitted carpets, painted woodwork and moved furniture in & out; all while I had tenants in the house. This site is a gamble but I highly recommend this team.
Robi paiting decorator
No reviews yet
Extension Builder in Harrow, Greater London
We perform work reliably and to a high standard
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lnk.brickwork
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
LNK brickwork professional team has over ten years of experience in London's construction industry, working with commercial and residential customers locally. Property extension, build a garden wall, need a paving job done or plan a new build, you can count on LNK BRICKWORK. Our commercial projects include new construction, repairs and restorations. We can also plan, manage, and build multi-phase jobs.
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Latest review:
Bricklaying- 10 May 2019
Excellent work recently carried out to a very high standard. A very polite and professional team who delivered everything and more above my expectations. Would definitely recommend this company and use again.
Planetium Construction Ltd
Rating: 4.5 out of 5
Extension Builder in Harrow, Greater London
Im Adrian based on South West London and surrounding area ,Planetium Construction Ltd Will be your favourite .We have a trusted, friendly and professional team of tradesman with +10 years experience. Our aim is to provide on time full property maintenance and refurbishment to a very high standard at a competitive price ensuring our customers are completely satisfied.
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Latest review:
Bathroom Fitting- 2 Jan 2025
Extremely Disappinted with Planetium Construction- I hired Planetium for a 59k renovation job. Initially, the workmanship was acceptable only because I supervised closely and had them redo substandard work multiple times. However, before the job has been complete, I discovered already a roof leak in the master bedroom, direcly under the newly renovated bathroom. Despite my repeated requests, Planetium refused to take responsiblity or fix the issue. Just telling me need additional charges for the work. Worst still, Adrian the owner, demanded I pay the final balance of 1840 before they would address the GF heating which stopped working after they installed the new controller. When I reasonably refused to pay before they complete the job , Adrian swore at me over the phone the most offensive language. Furthermore, they promised to replace a new Miele microwave for the one they damaged during installation but now just walked away. Leaving me unresolved issues and additional repair cost!
Tan & Co Developments Ltd
New on MyBuilder
Extension Builder in Harrow, Greater London
Welcome to Tan & Co Developments Ltd. We are a reliable and professional building company covering London and the surrounding areas. We specialise in extensions, renovations, refurbishments, flooring, painting & decorating, brickwork and general building services. Our goal is simple – to deliver high-quality workmanship, honest advice and excellent customer service on every project, no matter the size. We take pride in keeping our work areas clean, completing jobs to a high standard and maintaining clear communication throughout the process. Whether you’re looking to renovate a property, improve your home or undertake a larger building project, we’re committed to providing a professional and stress-free experience from start to finish. Get in touch today for a free quotation and friendly advice. Built on Trust, Driven by Quality.
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Emperor Contractors Limited
No reviews yet
Extension Builder in Harrow, Greater London
This is a construction company with many connections within the industry. Quality and longevity describes our state of works. We have a portfolio of many projects which all of them have been successful.
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Franzosi Brickwork
No reviews yet
Extension Builder in Harrow, Greater London
Newly qualified bricklayer after 3 year apprenticeship looking for small jobs.
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B & M Home Improvement
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
We are a local and reliable Plumbing, gas safe and Home Improvement Company in London and surrounding areas.I gained my experience working in the Plumbing and gas department. No matter whether you require help with plumbing, power flushing, boiler installation, bathroom, kitchen, extention, flooring we take on all building work. We provide a full interior decorating service for domestic and commercial.
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Latest review:
Extensions- 10 Apr 2014
Max and Bob completed the extension on time and within budget. There were no hidden extras and despite Bob being on holiday for two weeks, Max worked hard and lon. The extension is 6m x 5m. There were issues with Building Control which Max sorted out and did everything to meet their requirements. The extension is built to a high standard, kitchen cabinets fitted well, tiling very good and we are pleased with the quality of their work. We are using B&M again as we are confident that although they are not tghe cheapest, the quality of their work is of a high standard. Besides, it is always a pleasure to deal with Max who is a gentleman, patient and listens to what is required.
london construction company
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
Established in 1994 , Family run business . Friendly reliable service , Extensions / lofts and landscape specialist
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Latest review:
Extensions- 15 Feb 2026
Incredibly professional, super fast response, great quality of work, sound and thorough advice, available and patient at all times - Terry did a great job putting together my garden office installation at short notice despite inclement weather. I can vouch sincerely for his work and will definitely recommend him
FLV PROPERTY LTD
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
At FLV property ltd we are a team of skilled professionals with extensive experience in the construction industry for over 30 years. Whether you are planning a new build, an extension, a renovation or bespoke projects, our expertise ensures that every job is completed to the highest standards on and within budget. What we offer; •A team of dedicated professionals •Architects •Structural Engineers •Surveyors •Multi skilled tradesmen Attention to detail from design to composition. Our promise; We understand that building projects are significant investment's, and our goal is to make the process as smooth and stress free as possible. From initial consultation to project completion, we work closely with you to ensure your expectations are not only met but exceeded. LETS BUILD TOGETHER!
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Latest review:
Gus and Frank were brilliant. Their attention to detail and care for our project was evident. There was already an issue with our floor which Gus and Frank rectified for us before doing the tiling. The final finish was immaculate. We liked their work so much that we also got them to fit our kitchen worktop. Good communication and clarity throughout the job. Would definitely recommend!
Cocis Construction Group
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
Cocis Construction Group LTD is a family-run construction company with over 25 years of hands-on experience in the trades. We specialise in home renovations, extensions, bathroom and kitchen refurbishments, and property development across London. As a young, ambitious company, we combine traditional craftsmanship with fresh ideas and modern techniques to deliver projects efficiently and to the highest standards. Our team takes pride in attention to detail, clear communication, and building lasting relationships with homeowners, landlords, and property investors alike. At CCG, we don’t just build structures—we bring visions to life, turning ideas into beautifully finished spaces. Contact us today for a free quote and see how our expertise and dedication can make your next project a success.
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Latest review:
Cocis Construction Group done the full interior painting of our 5 bedroom house and we are really happy with the result. The team was polite and worked very hard every day. They kept things clean and finished everything on time like they said they would. The paint finish looks great and the whole house feels fresh again. Would definitely recommend them if you need painting done.
Barnet Builders
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
Barnet Builders Amir Gunić I am pleased to introduce my company, Barnet Builders, a trusted name in groundworks and construction services. With over 20 years of hands-on experience in both domestic and commercial projects, I have built a reputation for reliability, quality workmanship, and a professional approach to every job. At Barnet Builders, we own and operate a full range of equipment, including a digger and specialist groundwork machinery, allowing us to deliver efficient and cost-effective solutions. From small residential jobs to larger commercial developments, we pride ourselves on meeting deadlines, maintaining high safety standards, and ensuring complete customer satisfaction. Our services cover all aspects of groundwork, including excavation, site preparation, drainage, landscaping, and more. In addition, we also specialise in house extensions and loft conversions, helping homeowners maximise their living space with practical and stylish solutions. If you are looking for a dependable and experienced partner for your next project, we would be delighted to discuss how Barnet Builders can help you.
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Latest review:
Groundwork & Foundations- 6 Jun 2026
Amir and his team completed the job at speed and to spec and were very good in tidy up post completion. Would recommend for any building work.

3.9

Top rated Extension Builders

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

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

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, Greater London 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, Greater London who are available and interested can respond to your post.

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

What are the hourly rates of extension builders in Harrow, Greater London?

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

Find extension builders in Harrow, Greater London with MyBuilder

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

Step 2: Compare different extension builders in Harrow, Greater London

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

Step 3: Hire Harrow, Greater London extension builders with confidence

After gathering all the information and quotes from your chosen home extension builders in Harrow, Greater London, 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, Greater London extension builders are ready to help. Use MyBuilder today to find the right professional for your home extension.

What to ask a Harrow, Greater London extension builder before hiring?

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

An extension builder in Harrow, Greater London 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, Greater London 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, Greater London?

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, Greater London 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, Greater London 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, Greater London

Can an extension builder in Harrow, Greater London help with planning permission?

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

Many Harrow, Greater London 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, Greater London help with materials and finishes?

Yes, most extension builders in Harrow, Greater London 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.