Extension Builders in Harrow, Greater London

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

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Some of our top rated extension builders in Harrow, Greater London

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GRAND DESIGNS INTERNATIONAL LTD
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
Grand Designs International (GD) | Architectural, Engineering & Construction Services At Grand Designs International (GD), we are dedicated to delivering high-quality architectural, engineering, and construction services tailored to meet our clients’ unique needs. Backed by over 20 years of expertise, our team specializes in transforming visions into reality—whether you're planning a new build, home extension, loft conversion, or full-scale renovation. With a strong foundation in innovation, sustainability, and precision, we provide end-to-end project solutions, from initial design and planning permissions to structural calculations and final construction. Our commitment to quality, efficiency, and client satisfaction ensures that every project is completed to the highest standards. Why Choose Grand Designs International? ✅ Full-Service Expertise – From architectural planning to construction, we handle every stage seamlessly. ✅ Planning & Building Regulations Specialists – We navigate approvals efficiently to prevent delays. ✅ Experienced & Certified Team – Qualified engineers, architects, and builders with a proven track record. ✅ Tailored Solutions – Every project is custom-designed to meet your style, space, and budget needs. ✅ Transparent Pricing & Project Management – No hidden costs, just reliable service with regular updates. ✅ Fast Turnaround & On-Time Delivery – We work efficiently without compromising quality. Our Services 🏡 Architectural & Planning Services Planning Applications & Building Regulations Approval Concept & Detailed Design Interior Design & Space Planning 3D Visualizations & Rendering Enforcement & Retrospective Planning 🏗️ Structural & Engineering Design Structural Calculations & Drawings Civil & Structural Engineering Services Quantity Estimation & Cost Planning 🔨 Construction & Building Services Home Extensions & Rear Extensions Dormer Loft Conversions & Flat Conversions New Build Homes & Full Renovations Project Management & Site Supervision Construction Planning, Procurement & Logistics Quality Control & Safety Management At Grand Designs International, we believe in delivering excellence, one project at a time. Our reputation for integrity, professionalism, and top-tier craftsmanship makes us the preferred choice for homeowners and businesses across London and beyond. 📞 Get in Touch Today! Let’s discuss your project and bring your dream home to life.
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Latest review:
★★★★★ Highly Recommended! I had an existing 3-bedroom rundown property and contacted multiple builders before meeting Director Mr. Q Nawaz. From our first meeting, I was impressed by his ideas and the fact that Grand Designs could provide all services in-house. Initially, I proceeded only with the planning application to see if what he promised was possible—and YES, he delivered! My application was approved as he assured me. Seeing this success, I entrusted them with the entire construction project, and Grand Designs completed it within just 6 months, despite the challenges of COVID-19. Not only did they build my project, but they also added significant value to the development. I’m proud to have worked with them, and their exceptional work on my St Albans development is now featured in their portfolio. Within one year, the value of my property increased by £500,000—a testament to their expertise! Extremely professional, highly skilled, and very reasonably priced. You don’t need to go anywhere else—Grand Designs is the complete package!
The Construction Collective LTD
No reviews yet
Extension Builder in Harrow, Greater London
Your Premier Choice for High-End Construction in North London & Barnet With over 25 years of experience, The Construction Collective Ltd is a specialist building company dedicated to delivering premium residential and commercial projects. From luxury home transformations to large-scale structural works, we pride ourselves on exceptional craftsmanship and a seamless client experience. Our Expert Services Include: Bespoke Extensions & New Builds: Creating high-value living spaces from the ground up. Loft Conversions: Expert structural transformations to maximise your home's potential. Complete Renovations & Refurbs: Modernising properties with high-end finishes. Commercial & Industrial Fit-outs: Professional structural solutions for business units. We offer a "one-stop" service, managing everything from design and planning through to the final build. With a dedicated project manager for every job, we ensure your project is completed on schedule, within budget, and to the highest possible standard. Contact us today to discuss your next project.
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Archdom.ltd
No reviews yet
Extension Builder in Harrow, Greater London
We are a design and build company with expertise in architectural, interior design and construction. Offering a complete service from design to final build. We develop the full potential of your space and build it to perfectly match our design.
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Luxury design masters Ltd
No reviews yet
Extension Builder in Harrow, Greater London
Hi we are in LDM (Luxury Design Masters LTD) the best team to build your home dream we are specialist in commercial & domestic renovation we can make your place look luxurious and we can work it on your budgets we do all building works from AtoZ we are £10m insured cover we done Westfield, Sweeden, Gloucester quays shopping centres and many luxury homes we can proven it. we try to help many projects to be look gorgeous and beautiful. All our builders high qualified with many years experience so you can trust us and put your home in the safe hand. In LDM we works hard to make all our customers happy as your reference is very important for us hope to see you soon 👍🙏
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rr.construction
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
Working with: simfonia kitchens,howdens kitchens,ikea kitchens,wren,benchmarx,magnet,b&q kitchens,selco,wickes homebase.8 year experience of building in uk
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Latest review:
Hard Flooring- 8 May 2019
I was very pleased with Igor’s work on the flooring and under floor heating, so decided to ask Raimundas to quote for a large bathroom, hallway, fitted kitchen, rewiring of all electrics and flooring throughout the rest of the flat. Due to work and my partner living overseas, I needed to trust somebody for a long length of time with my keys and my property. I was able to have a lot of the work done while not in the country, communicating with pictures, videos etc. Obviously this was important for me and made having the work done easier. There were also many problems with the kitchen delivery and other things that didn’t go according to plan. Raimundas was patient and polite at all times, even though it was sometimes rather frustrating. I highly recommend his services, and would definitely consider RR Construction for the next job
JED BUILDERS LTD
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
A limited company established in 2016. More that 8 years experience in construction business. We undertake all building works, big or small, managing and looking after project so the client can have the best results possible.
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Latest review:
Kitchen Fitting- 14 Dec 2018
Very lovely and professional and clean. Very prompt/punctual and worked efficiently , will be using them again to do more work in my property. Definitely with recommend them to anyone ! 10/10 from me ! Good service delivery
Arworks
No reviews yet
Extension Builder in Harrow, Greater London
I have had the privilege of working on a 260-year-old Grade Listed building in Islington, London, under the close supervision of conservation inspectors. This project required a careful balance of tradition and innovation — I combined the use of modern machinery externally with traditional, delicate methods internally to ensure the building remained completely scratch-free. My experience has given me a deep respect for heritage projects as well as the skills to deliver high-quality results on modern refurbishments.
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Army Build Ltd
New on MyBuilder
Extension Builder in Harrow, Greater London
ARMY BUILD BUILT RIGHT. BUILT TO LAST. At Army Build, we take on everything from smaller repairs and improvements to full property renovations, extensions and commercial projects. We believe building work shouldn’t be complicated. We turn up when we say we will, keep you updated throughout the job and take real pride in the standard of our work. Whether you already know exactly what you want or you just need some advice on where to start, we’re happy to come out, take a proper look and talk through the best options for your property. Our services include: - Full renovations & refurbishments - Extensions & loft conversions - Kitchens & bathrooms - Plumbing & heating - Electrical works - Plastering & structural works - Carpentry & joinery - Decorating & finishing - Roofing & repairs - Commercial works & office fit-outs - General building & property maintenance We treat every property with the same care and attention we’d expect in our own, and our aim is simple: good communication, quality workmanship and a job done properly. Covering London and surrounding areas
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NSL Sons & Co
No reviews yet
Extension Builder in Harrow, Greater London
NSL Sons and Co – Expert handyman and repair services you can trust. Fast, reliable, and high-quality work for every home and business.
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ZNS Construction Ltd
No reviews yet
Extension Builder in Harrow, Greater London
We are a full service construction company. Typical works are extensions, loft conversions and refurbishments. We have vast knowledge in groundworks and drainage and formwork. Qualified electrician for the niceic
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Cekamaintenance ltd
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
With over 20 years in carpentry, plumbing, kitchen and bathroom fittings, and general building maintenance work.
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Latest review:
Carpentry- 2 Aug 2025
Excellent service from start to finish, tradesman as they should be!
EEOC Ltd
No reviews yet
Extension Builder in Harrow, Greater London
Emilian has been in construction for over 20 years. Starting out FROM solving steps to FIXING things right after high school, he HAS learned in UK how to build a house from the foundation up. Few years ago he turned his passion AND KNOWLEDGE into a business that focuses on the long-term goals and satisfaction of his clients. As a Building , Refurbishing Construction , EEOC LTD can be defined as a complex construction projects.
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alpha green construction
Rating: 5 out of 5
Extension Builder in Harrow, Greater London
I have 25 years experience in the trade.specialise in innovation and reliability. Trade built company generally around masonry , roofing and all other structural undertakings. We specialise in loft conversions and house extensions , masonry and landscape gardening. We also provide design and build schemes for the above topics.
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Latest review:
Extensions- 14 May 2019
We love Berry, he has followed our project from the beginning to the end and he has been there all the steps of the way. He listened to our ideas and enriched them with more of his adding his special attention to details skills. For every problem, we had along the way he talked to us making sure we were happy with alternative solutions. Plus he is able to create a friendly working environment which makes the invasion of your house less intrusive, he has been very respectful of our space. We can genuinely say that he has gone beyond our expectations, and will be very happy to do future works with him. Luca and Nick
SLRA Ltd
No reviews yet
Extension Builder in Harrow, Greater London
Builder company, refurbishment and new build. Bespoke joinery, wardrobes, kitchens etc.
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B&D Build Ltd
No reviews yet
Extension Builder in Harrow, Greater London
We are B&D Build with over 12 years of experience in construction and we undertake projects such as, extensions loft conversion, refurbishment etc. We operate from small to big projects so whether you are looking to expand, renovate or even just remodel you can trust the B&D build to achieve your vision. Strong client communication is our priority leading to skills and quality in every job we undertake.
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SK
No reviews yet
Extension Builder in Harrow, Greater London
I run carpentry businesse or im also carpenter from 15 years we cove also plasterboard,paint all kind of works
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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.

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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.