Extension Builders in Harrow, Greater London

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 3.9 (16 reviews)

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

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, Greater London

3239 Results

Sort by:

Adrian Popa
No reviews yet
Extension Builder in Harrow, Greater London
Hi . I can undertake loft conversions extension s , carpentry, bespoke furniture, plumbing, electric, full refurbishment.
Get in touch
Maclondonbuilding
Rating: 4.9 out of 5
Extension Builder in Harrow, Greater London
MACLONDONBUILDING specialist in general construction and renovation services. All kind of house conversions . Our works are performed at the highest standard with attention to the details. Professional team always happy and enjoyed of the work.
Get in touch
Latest review:
Tiling- 16 Jan 2026
Mac was fantastic and went above and beyond to do the job to a high standard, working well into the evening to get it done. I’d recommend him without hesitation for any work you need doing - big or small. We’re delighted with the finished product.
SAM DESIGN & BUILD LTD
Rating: 4.4 out of 5
Extension Builder in Harrow, Greater London
Having a wide range of experiences in designing and constructing extensions, loft conversions, alterations and new buildings with planning, structural drawings and calculation, we provide full range of service from planning and design to construction. Electrical, gas safe, plumbing and heating are also part of our wide range of services. Load bearing wall removal, chimney breasts removal, refurbishing kitchen and bathroom were also one of the most accomplished projects in last year. Look forward to hear from you.
Get in touch
Latest review:
Extensions- 3 Oct 2025
Job was to convert WC in outbuilding into a full bathroom, do walls and ceiling in outbuilding to convert into an office space. Price was agreed with things planned, still with some issues towards later part of job, It worked out in the end. Overall I am giving 3-4 stars as quality of work is good. Just need to have things written down with him, and a thorough discussion on plan before commencing work and agree on payment plan. suggested to keep 20% to be paid at completion.
DSB Construction ltd
No reviews yet
Extension Builder in Harrow, Greater London
DSB Construction is a multi-skilled company operating in construction, residential housing, refurbishments and construction maintenance, offering services to a diverse range of clients in the UK. With the help of our partners, we can leverage ideas, skills and entrepreneurial flair to deliver top-quality work in all sectors. We design, build, restore and refurbish buildings throughout the United Kingdom. We specialize in developing residential property specifically made for modern living.
Get in touch
Surflex Ltd
No reviews yet
Extension Builder in Harrow, Greater London
At Surflex Ltd, we specialize in renovation, refurbishment, and complete construction services. From flooring, painting, wallpaper, and decoration to full property upgrades, we provide everything homeowners need to transform their spaces. Why Choose Us Complete service – One trusted team for every stage of renovation and finishing Skilled craftsmanship – High standards of quality and attention to detail in every project Reliable delivery – Projects completed on time, with minimal disruption to your home Tailored solutions – Designs and finishes that reflect your style and needs Why Clients Trust Us We are committed to professional standards, honest communication, and long-lasting quality. Most of our business comes from recommendations and repeat clients, proving the trust we build with every project. With Surflex Ltd, homeowners can be confident their property is in safe, expert hands.
Get in touch
Thebuilderbrothersltd
No reviews yet
Extension Builder in Harrow, Greater London
We are a team of 3 multi skilled workers who can remove ,repair ,collect and create. No job to big or small
Get in touch
Raj Builder
No reviews yet
Extension Builder in Harrow, Greater London
MyBuilder is a UK-based online marketplace and matchmaking platform that connects homeowners with local, reliable tradespeople (such as builders, plumbers, electricians, roofers, and other home improvement professionals. MyBuilder is a UK-based online marketplace and matchmaking platform that connects homeowners with local, reliable tradespeople (such as builders, plumbers, electricians, roofers, and other homes - **For homeowners**: Post a job for free (e.g., extensions, kitchens, bathrooms, roofing, gardening). The platform uses a matchmaking system to alert relevant, verified tradespeople in your area. You receive interest from tradespeople, review their profiles (including past work history, customer feedback, ratings, and references), chat directly, compare quotes, and hire the best fit. No fees MyBuilder is a UK-based online marketplace and matchmaking platform that connects homeowners with local, reliable tradespeople (such as builders, plumbers, electricians, roofers, and other home improvement professionals). Founded in 2018 by Raj (a stonemason and roofer frustrated with traditional ways of finding work), MyBuilder started as a simple idea to help consumers find trustworthy local builders and tradespeople more
Get in touch
Brick & Block work
No reviews yet
Extension Builder in Harrow, Greater London
We are specialist in Brick & Block works and all building work undertaken With the experience of more than 20+years
Get in touch
D. Wallace Building Services
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
Hi, I'm Dave, a carpenter by trade with over 40 years experience In the building trade. I have a network of professional tradespeople I can call on which enables me to undertake any small repair jobs, medium sized jobs, like kitchens and bathrooms, right through to extensions and loft conversions . I have worked as a site manager and project manager in the past, so l have experience with Building Control, Planning Depts as well. I also make furniture and bespoke carpentry items.
Get in touch
Latest review:
Carpentry- 15 Nov 2023
Great service! David responded promptly and came out to review/measure up and provided a good quotation. Our window sills were installed within the week and we are very pleased with how it went. David was communicative, got on with the work and cleared up after. Would highly recommend.
Mario Services
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
Mario & Alex Construction LTD specialise in construction and building services, complete property refurbishment, house extensions and loft conversions. Provides unmatched customer service. Our commitment to small,hudge integrity, providing the highest value and satisfied customers, has been the ingredient that has fueled our growth from the beginning. We ensure that all our work is professionally managed so that the result is of outstanding quality, cost-effective.
Get in touch
Latest review:
Bathroom Fitting- 20 Jan 2023
We highly recommend Mario & his team. They fitted a new kitchen & bathroom to a really high standard within a short, timeframe. They work hard, are friendly, professional & honest, my neighbour even commented on how considerate they were! Upon first meeting Mario we were impressed by how organised he was. He arrived on time with the description we’d posted on my builder & went through it methodically. We had A LOT of questions! He answered all of them & didn’t rush us. We received a competitive quote within a day as promised. It included everything we discussed & he quickly answered our follow up questions. We wanted an accurate idea of the cost of electrical work & Mario arranged for his electrician to come & inspect/quote before we’d appointed Mario the job. Our kitchen & bathroom is complicated, with lots of difficult angles. Damp, unlevel floor, unlevel windows, a low ceiling were uncovered in the bathroom. Mario did well to identify solutions, giving us expert advice. Pipes were neatly chased into the wall. Underfloor heating & LVT, tiling, grouting & painting all done to a very professional finish. He kept us informed of progress, checked our preferences & was patient when we had supply delays, finding ways to ensure the job finished on time enabling us to move from our temporary accommodation back home in time for Christmas. He promptly fixed some minor issues after the job finished. We highly recommend Mario & would use him again.
Innovation Construction Design & Build Ltd
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
Innovation Construction Design & Build are a reliable & professional business dedicated to designs and finishes of the highest quality, tailored personally for the customer. We offer a friendly, methodical, personal and tidy service. Client care, satisfaction, reliability and being trustworthy is our company ethos and we ensure our company adheres to these core values as our basis for each project we are working on from small domestic projects to large commercial contracts
Get in touch
Latest review:
Extensions- 5 Oct 2020
Billy, Darren & the team have just finished the single side and rear extension & refurb works on my house, and they've done a brilliant job! From the start, quotations we're received promptly and competitively priced. Communication for commencement of works (during COVID-19) was always going to be uncertain but, Billy dealt with this really well and scheduled the work in as soon as was achievable. From the first day on site it was clear the team have worked with each other for years and are willing to put the extra time in to get the build done quickly, but correctly. Communication throughout build was processed well and the guys are on hand to respond to queries and questions at all times. We had a delay in the project which was unforeseen, but we sat down and came to an agreement and the extra work was carried out quickly and the project was wrapped up in really good time. I wouldn't hesitate in recommending Innovation for any building or decoration work to friends and family as the end result of our place is stunning! Special shout out to Jordan, Fog, Florin (wood work wizard) & Joy for their hard work throughout. Thank you Innovation!
Imeraj
No reviews yet
Extension Builder in Harrow, Greater London
I am a construction worker . I had 5 years working for a civil engineering company like supervisor . I have lot of skills referring construction ( steel erection , timber works , underground works etc ) . Last year i finished level 1 and 2 in plumbing aswell to complete more professional skill and manage the common problems in most of new and existing properties . Contact me if you have something and let proceed to fix or upgrade your properties .
Get in touch
Perry earth works
No reviews yet
Extension Builder in Harrow, Greater London
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.
Get in touch
BYKEW
No reviews yet
Extension Builder in Harrow, Greater London
I’m very reliable person
Get in touch
A brick project construction ltd
No reviews yet
Extension Builder in Harrow, Greater London
As an experienced and dedicated builder, I take pride in delivering high-quality craftsmanship and reliable service for every project. With a strong focus on attention to detail, clear communication, and customer satisfaction, I work closely with each client to bring their vision to life, whether it’s a small renovation or a large-scale construction. I understand that your home is your most important investment, and I’m committed to completing every job to the highest standard, on time, and within budget. Let’s work together to create something exceptional.
Get in touch
a-z renovations and construction
No reviews yet
Extension Builder in Harrow, Greater London
My name is Avni, Our company is called 'a-z renovations & construction' we take all different kind of projects whether they are small or big. all of our jobs are mainly recommended. our jobs are: Extensions, loft conversions, mezzanine floors, plastering and plumbing, wall & floor tiling, painting and decorating, kitchen and bathroom fitting, carpentry, patio and garden fixing. we cover London and home counties.
Get in touch

3.9

Top rated Extension Builders

Our Extension Builders in Harrow, Greater London, are rated 3.9 out of 5 based on 16 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, 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.