Extension Builders in Harrow

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

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

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 Harrow

3047 Results

Sort by:

ax developments ltd
Rating: 5 out of 5
Extension Builder in Harrow
We are pleased to introduce ourselves as a new construction company with more than 30 years in the business. We are experienced in a wide range of construction projects, from residential to commercial buildings. We believe in providing high-quality services at a fair price. We take pride in our ability to meet and exceed our customer’s expectations. We are confident that our skills and experience will be a valuable asset to your project.
Get in touch
Latest review:
Conversions - General- 31 May 2023
Great job, also waited patiently for cement to dry so could complete on time. Very pleased
Laurentiu Goian
Rating: 4.8 out of 5
Extension Builder in Harrow
The Goian Group with over 18 years of experience in the UK's construction industry is ready to deliver value to your dream home, office or site. FREE painting for all house extensions.
Get in touch
Latest review:
Extensions- 2 Oct 2024
He did the extension well, brick work is good, rendering on front of house good, terrace and wall with the neighbours good ,toilet under the stairs good, dividing wall in the living room with sliding doors good, kitchen installed good. Fence wall in front of house good brick work wrong bricks but it’s ok. Herringbone parchet wrong with gaps and lifted, rendering on the side of house wrong with marks, the new boiler took 2 months to make it work and the radiators still don’t work. Electrical work bad, after bringing another engineer to check we discovered at the boiler live cut cables that were loose and veri dangerous. Took 4 months to finish job we waited one month for the plumber who either way did a bad job. Laurentiu did not finish the job because of plumbing and rendering, and we ended in bad terms, he left us money to compensate for it. I would recommend him for extensions and any brick work, he needs to improve in pluming, electrical, flooring and rendering.
Moraru building
Rating: 5 out of 5
Extension Builder in Harrow
Hi,my name is Ionut, I m Romanian man and general builder I can do lot of jobs . I m profesional,prompted and quality jobs. Free quote for all the possible customers.
Get in touch
Latest review:
Roofing (Flat)- 13 May 2026
Was punctual, explained everything clearly and was reasonable on price. Will use again, Thanks!
Wall Done SP
Rating: 5 out of 5
Extension Builder in Harrow
We believe your home should evolve with your lifestyle. Whether you're expanding your living space with a loft extension or completely renovating your property, we turn your ideas into reality.
Get in touch
Mad property care Ltd
Rating: 4.4 out of 5
Extension Builder in Harrow
Professional builder with many years’ experience, I get the job done. In the 16 years spent in construction I picked the skills required to get the work done without the need of another specialist. I’m a carpenter by trade but I’m also a plumber & so much more, I’ve dealt with all kinds of trades, building control, engineers, architects, electricians.
Get in touch
Latest review:
Conversions - General- 16 Apr 2024
Job completed. Very professional and efficient service. Would highly recommend.
HWB construction
Rating: 5 out of 5
Extension Builder in Harrow
Our executive team's come from diverse backgrounds such as design, engineering and management. Dedicated and focused, our vision has always been to be a dynamic and innovative organisation. The joint experience of our executive team is well over 20 years and provides us and our partners with a significant level of expertise which is applied to each project. HWB’s unique approach means we can be flexible and bespoke in all we do when delivering excellence in the construction industry.
Get in touch
Latest review:
Extensions- 28 Oct 2018
We appointed HWB to carry out a full refurbishment on our house, this involved re-gutting the interior and building an extension and loft conversion plus some landscaping in the garden. We spoke to many builders but finally appointed HWB based on their previous projects and professionalism. Appointing builders for any work is always difficult however we are delighted that we went with HWB. Throughout the project they have demonstrated high levels of professionalism, were very organised and worked to very high standards. They were collaborative throughout the whole project and kept us informed at every stage. As the project developed there were some changes made and HWB were flexible and open to new instructions made by us, as well as giving us valuable advice. Farag, Ayoub and the HWB team were always available to answer any questions and provided us with constant feedback on progress as well as identify new solutions to aid the development. They have a great team of workers who work to a high standard and are supervised throughout the project. We made the right decision going with HWB Construction and have no hesitation in recommending them.
Restora Developments LTD
Rating: 5 out of 5
Extension Builder in Harrow
Hi! Here at Restora Developments we pride ourselves in having a diverse range of skills. Our bread and butter is new build homes and large developments, however we have formed a sub division aimed at end clients and home owners for smaller taks. With all in house; - carpenters - roofers - plumbers - electricians - brick layers - landscapers Etc. We take on all work from simple bathroom refurbishments to building your dream property from the ground up!
Get in touch
Latest review:
Groundwork & Foundations- 18 Feb 2022
they did for me a good job and very high standard and price wise
PBX DESIGN & BUILDS LTD
Rating: 5 out of 5
Extension Builder in Harrow
Hi, This is shah from PBX DESIGN & BUILDS LTD. We do all types of building works like extension, loft conversion, roofing, plumbing, tiling and landscaping. We can beat any quote.
Get in touch
Latest review:
Landscaping- 23 May 2026
Very happy with the job they did they were really quick they came on time and finished the job in 1 day
Pithadiya Construction
Rating: 5 out of 5
Extension Builder in Harrow
We are new to MyBuilder but not new to building! We have over 12 years’ experience in the trade. Specializing in New Builds, Extensions, Loft conversion, Complete renovation and we are a professional, caring, and high quality building services. We are based in Hounslow, and we cover West London, North West London, South West London and all surrounding
Get in touch
Latest review:
Extensions- 17 Jun 2022
I have my rear house extension completed and a brand new kitchen installed by this firm. The project went brilliantly from start to finish despite the bad weather. The workers always turn up on time, rain or shine. Mr Ram and his team were pleasant to work with and they were always willing to listen to suggestions for improvement. They have eye for details making sure the works are completed to the highest standard without compromising the budget. I am pleased with the work and would highly recommend this firm unreservedly.
Tommy Construction
Rating: 5 out of 5
Extension Builder in Harrow
Tommy Construction I offer a full range od home refurbishment services including:plastering,painting,decorating,Floors,woodwork,tiling, Plumbing,electrical services,complete house renovations,driveway,porch,patio,decking,brickwork. I have 13 years experienced and skilled team that can adapt their skill-set to many tasks.
Get in touch
Latest review:
Bathroom Fitting- 19 Feb 2022
We were very impressed with Tommy Constructions. We have recommended him to friends. He was very professional. He finished the job when he said he would - to a very high standard. We are very happy with our new bathroom.
M&J Home Construction LTD
Rating: 5 out of 5
Extension Builder in Harrow
Dedicated team, hands-on everything with more than 15 years experience on the market, we can prove that small things can creat great expectations. Our team is dedicated to perform the perfect job for you from simple handy work to Plumbing, Electrical, Kitchens and Bathrooms, , Flooring, and many others. We cover London and 10 miles radius,
Get in touch
Latest review:
Bathroom Fitting- 23 Apr 2026
M&J done a great job redoing my whole bathroom and fitting in all the new tiles and shower units along with basin and toilet. If you are in doubt take this review as your reason to book this team in to get a fantastic job done.
10/ten construction ltd
Rating: 5 out of 5
Extension Builder in Harrow
Hi I am Landi, 33 years old, I’m in construction industry over 15 years. Build your future with us! We are constantly developing our skills and expanding the knowledge, so as to provide you with modern and effective services. Our team is always up-to-date with all the most important novelties in the field, what makes it possible for us to apply innovative techniques and use professional tools. Thanks to that, we can perform complete refurbishment perfectly. If you choose us to be your building contractors, you can be certain that every project will be precisely planned and carried out. 10/TEN CONSTRUCTION LTD
Get in touch
Latest review:
Carpentry- 6 Dec 2024
We recently had Landi around to quote on a number of jobs we needed doing around our house. We booked him to fix our roof, which was leaking water - he and his team did an absolutely fantastic job. They were responsive, thorough and did a great job. We won't hesitate to recommend him to anyone and get him back for any work we need doing.
All in one builders
Rating: 5 out of 5
Extension Builder in Harrow
At All In One Builders we take pride in being your trusted partner for all your construction needs. With a wealth of experience and a commitment to excellence, we specialise in a wide range of building services tailored to meet your unique requirements.
Get in touch
Latest review:
Akash made sure the job was complete exactly how he said it would be, he provided reliability during the installation of our kitchen and answered all questions very professionally. The builders were well aware of the conversations my mother and I had with Akash and so put our mind at ease. The installation itself was very quick (the tear down was very much completed in a few hours) and installed over the weekend. They were very hygiene aware and set up a cover between the kitchen and the rest of our house and didn’t disrupt our home living. They cleaned up before they were gone to very high standards without us even asking them too, all I’m sure is due to Akash’s excellent organisation skills.
GNG Building Services
Rating: 4.8 out of 5
Extension Builder in Harrow
With our extensive experience in home improvements, refurbishments, and building work, no job is too small or large. We've helped countless homeowners across our local area with creating their dream home. Get in touch today to see how we can help you. In case just a single room refurbishment isn't enough and you want to renovate your entire home then look no further than GNG Building Services Ltd. We have the skills to renovating your home a breeze!!!
Get in touch
Latest review:
Hard Flooring- 21 Sep 2021
Very pleased with the service provided by Nick . Our hard wood flooring in dining area was badly damaged but it was replaced and restored very professionally to its original glory. He is very nice, polite person and very easy to communicate. He is an excellent carpenter and if needed I will use his service again.
Bischell Construction Limited
Rating: 4.9 out of 5
Extension Builder in Harrow
Design & Build projects that squeeze more out of every pound spent. We’ll deliver an outcome for you that looks a lot more expensive than it really is. It will be tailored to your lifestyle, designed for your senses and fine-tuned to minimise lifetime costs. If you have an eye on value, or looking for maximum ROI, we’ll deliver more for less. It’s about smart design and construction, so the result gives you more performance, better quality of life and a stronger return from your budget.
Get in touch
Latest review:
Architecture- 4 Jun 2026
I recently worked with this structural calculation engineer for a project that required precise drawings, and I couldn’t be happier with the outcome. The calculations were spot-on, and the drawings were clear and detailed, making the process seamless with my builders. Not only was the quality top-notch, but the pricing was fair and transparent. Communication was excellent throughout, and they delivered on time. Highly recommended!
Landi Builders Ltd Uk
Rating: 5 out of 5
Extension Builder in Harrow
I am a professional, reliable, and hardworking builder dedicated to delivering high-quality workmanship and excellent customer service on every project I undertake. I take great pride in my work and always aim to complete every job to a high standard, ensuring that my customers are fully satisfied with the finished result. I understand that choosing a builder is an important decision, and I always strive to provide a service that is trustworthy, professional, and stress-free from start to finish. My approach to building work is simple: be reliable, communicate clearly, work safely, and deliver quality results. I believe that professionalism is just as important as workmanship. Turning up on time, being respectful of a customer’s property, keeping the work area tidy, and maintaining clear communication throughout a project are all essential parts of the service I provide. I treat every job, large or small, with the same level of care, attention, and commitment. I have experience in a wide range of building and property improvement work, including general building, repairs, maintenance, renovations, interior improvements, exterior work, and property upgrades.I am happy to take on both small jobs and larger projects.
Get in touch
Latest review:
Kitchen Fitting- 8 May 2026
Keri did an excellent job in fixing our cooker extractor pipe. Easy to talk to, nice approach and work in a timely manner. If we need them again for our home, will definitely contact them again.

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.

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 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.