Extension Builders in Castelnau

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4.2 (20 reviews)

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Some of our top rated extension builders in Castelnau

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Bricklayer
Rating: 5 out of 5
Extension Builder in Castelnau
Brickwork . New build, extension . Garage
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Latest review:
Bricklaying- 10 Jul 2023
I am very pleased with the work done Excellent clean job Mr Bicol has carried out
OWA CONSTRUCTION LTD
Rating: 4.9 out of 5
Extension Builder in Castelnau
We are a medium sized groundwork company based in West London. We have over 18 years groundwork experience. We specialise in Drainage , Basements Reinforced concrete, Foundations, Block and beam , Paving , Fencing Etc . We pride ourselves in our work and customer satisfaction is our top priority.
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Latest review:
Groundwork & Foundations- 7 Feb 2026
Oli carried out the groundworks and demolition at my property and was on site every day with his crew, fully committed and hands-on throughout the job. I am an architect, and this was work on my own home, so my expectations were high. Oli met those expectations fully. He has a strong knowledge of groundworks and demolition, works carefully and methodically, and you can tell he genuinely enjoys what he does and takes real satisfaction in delivering the work exactly as required. He was always in a good mood, easy to communicate with, and a pleasure to have on site. I enjoyed discussing the project and hearing about other jobs he has completed over his 23 years of experience, which clearly shows in the quality of his work. I would highly recommend Oli for any groundworks or demolition works.
Alexi Construction Ltd
Rating: 5 out of 5
Extension Builder in Castelnau
At Alexi Construction, we take immense pride in being your trusted partner for a wide array of high-quality property solutions across the UK. Our commitment to delivering perfection to your proposition and exceeding all expectations is at the core of everything we do.
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Latest review:
Great work from start to finish, Suren was professional, reliable, and delivered high-quality service on time and on budget. Communication was clear throughout the works, and the final results exceeded expectations. Highly recommend Alexi construction to anyone looking for real quality work.
builder
No reviews yet
Extension Builder in Castelnau
14 years of experience in plastering, tiling, bathroom and kitchen fitting. I have my own team of skilled builders
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Swift Building Masters
Rating: 4.9 out of 5
Extension Builder in Castelnau
General Builder of over 40 years Experience. Carpentry & Joinery Background. I have worked on large and small Projects, Repair, Refurbishment, Extensions, Loft conversions and New-builds. Recently become a member of Federation of Master Builders. ALL WORK QUALITY ASSURED
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Latest review:
Extensions- 5 Nov 2016
Leslie carried out the following works: chemical damp injection to walls on rear extension, reroute down-pipe, repair fracture on rear wall, install gutter hedgehog. Hopefully, this will resolve some of the issues we had with damp, a blocked down-pipe and an overflowing gutter. Leslie arrived on time on the first day but was delayed a few hours the next day. However, the work still was done within two days as expected. Thank you!
Quinn's Builder's
Rating: 4.7 out of 5
Extension Builder in Castelnau
Hi my name is Chris my company is Quinn's Builder's. I have a motivated, reliable and friendly team that have over 20 years experience in the building industry. 100% great feed back from all my customers! We specialize in Full Refurbishments, extensions, patio's, kitchens/bathroom insulation , electrics, plumbing, roofing, flooring, decorating, window/door fitting, garden/fencing. We can carry out any job big or small. Contact us for a free quote.
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Latest review:
Restoration & Refurbishment- 8 Aug 2024
Chris completed the works at my house in June 2024, the works included: - removal of internal walls to make open plan downstairs - new kitchen - new WC - flooring - decorating - plumbing - electrics - bespoke joinery He was great to work this and completed the project to a very high standard. He attended site every day over a 4 week period and was committed to complete the job on time. I would recommend Chris and his team to others. Chris was even kind enough to install blinds, a media wall and build a wardrobe at no extra cost. Cheers!
Dominant construction ltd
No reviews yet
Extension Builder in Castelnau
Dominant Construction is a customer centric integrated building company specialising in home renovations, loft and basement conversions, and kitchen extensions. With over a decade of experience, we have designed our processes to ensure that our clients projects run smoothly - always on-time and always on-budget. We keep clear lines of communication at all times to make sure projects are collaborative and executed with our client's needs at the forefront.
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First Choice Builders
Rating: 4.9 out of 5
Extension Builder in Castelnau
Christopher Graham -Level 1,2,3 in Bricklaying Trowel Occupations. -NVQ Level 1,2,3 -Professional Development Diploma in Historic Building Conservation and Repair -Stone and Brick Repair for Historic Building Restoration -Building and Pointing with Lime Mortar In 2010 I started up First Choice Builders and haven't looked back since. Taking on all Bricklaying works, Fully Qualified with 15+ years experience. Have done extensive courses on Repointing and Brick Restoration. Mastering Tuck, Weatherstruck, Flush and all other types of pointing. Top quality brickwork guaranteed. Also have tower scaffold £150 per week hire. Which should save on getting a proper scaffolding which is a minimum of around £400. Please give me a call for a free quote.
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Latest review:
Bricklaying- 11 Mar 2026
Great Job by Chris, fairly priced and completed on time. Thanks
Asen Terziev
Rating: 5 out of 5
Extension Builder in Castelnau
I have been working in construction since I was 19.I have qualified as external wall insulation,rendering and plastering!Over the years I have undertaken bricklaying and roofing jobs as well!
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Latest review:
Plastering- 7 Oct 2022
Excellent work, very professional.
Cool Dudes Construction
Rating: 5 out of 5
Extension Builder in Castelnau
We do all sort of house renovations including new build extensions and loft conversions , bathrooms . Your satisfaction is our job
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Latest review:
Extensions- 13 Dec 2025
Most perfect guys to do the job. Nothing was to much trouble, very professional, we are absolutely in love with our extension and will 100% recommend and use cool dudes in the future.
NKN HOME CREATIONS LIMITED
Rating: 5 out of 5
Extension Builder in Castelnau
We are a reliable and experienced construction company committed to delivering high-quality workmanship with care and attention to detail. We specialize in home extensions, refurbishments, new builds, and loft conversions, ensuring every project is completed safely, professionally, and to the highest standards.
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Latest review:
Plastering- 2 Feb 2026
Happy with work, left job site tidy and clean. Will be happy to use company for future work. Thanks
SGB Water Engineering
Rating: 5 out of 5
Extension Builder in Castelnau
SGB maintain an interactive IT process, to ease transparency and movement of information data, to all parties involved in any one project. We have a combined 25 years professional experience in the civil engineering / construction management. We are experts in water utilities management enabling us to offer a variety of services and solutions in this area.
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Latest review:
Plumbing- 9 Dec 2020
Work completed and problem has been resolved .
alpha green construction
Rating: 5 out of 5
Extension Builder in Castelnau
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
K&L Construction
Rating: 5 out of 5
Extension Builder in Castelnau
We are a group of experienced contractors specialised in brick work, block work,tiling,rendering,plastering&decorating also in structure work,installing new beams, forming new floor levels & stud walls.We are more than happy to take on board all types,sizes & shapes of works & well prepared for a challenge.We as a team cover all building sector(BUILDING,PLUMBING,ELECTRIC,DECORATING,ALL IN ONE & MORE) so please don't hesitate to give us your trust and we promise you that we will deliver
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Latest review:
Conversions - General- 21 Jun 2025
Working with Petrit was a very pleasant and enjoyable experience. He and his team are friendly and open for discussions. They’re quick, affordable, and help with decision making. Would hire again! Have to say as well, as a woman, Petrit and his team treated my husband and I equally, unlike my experience with other tradesmen who direct all their conversations to the men. Petrit knocked opened up our living kitchen area, laid herringbone floors, replastered the property, installed new radiators, added a built in ladder to our attic, and re did our bathroom. He also helped us match the floor boards from an existing room and helped us source front and back doors for much better price than what we were getting quoted in East London. The painting of the entire house was done in a rush as we needed to move in, so the attention to detail fell down a little here compared to everything else that was done, but I wouldn’t hesitate to work with Petrit again!! After and before pics included!
ASC
Rating: 5 out of 5
Extension Builder in Castelnau
Plumbing & heating — full professional range ASC HEATING & PLUMBING is based in London and works across London and the surrounding areas. With 6+ years in business, we offer everything from emergency call-outs and repairs to installations, leak detection, drains, bathrooms, boilers, central heating, underfloor heating and commercial plant rooms — planned so you know scope, timescale and cost up front.
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Latest review:
Plumbing- 1 Apr 2026
Aurel and his son did a great job, really knowledgeable and helped with a difficult job. Not only were the results fantastic but the guys were a pleasure to have around.
Signature 1 Construction Ltd
Rating: 4.5 out of 5
Extension Builder in Castelnau
Signature 1 Construction LTD is a family run business with over 25 years experience in the building industry. We specialise in extensions, loft conversions and full house refurbs. Every job we undertake we take great care of the clients house and are experienced project managers will look after you from start to finish.
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Latest review:
Extensions- 30 Sep 2025
Overall, I’m very pleased with the work Marin has carried out for us and I’m currently in the process of instructing him to do more work. Marin built a high spec cedar shed for us with electrics and plumbing, some brickwork and laid composite decking. Marin came across, honest and reliable, which in itself is rare. He was on site most mornings to make sure his tradesmen were on the right tracks. Like with a lot of these things there were some issues along the way and I was highly impressed by Marin’s ‘no quibble’ approach to rectify any problems. I myself have a high attention to detail and am quite indecisive (nightmare client) and Marin was happy to work with me with changes to the project without incurring extra costs.

4.2

Top rated Extension Builders

Our Extension Builders in Castelnau, are rated 4.2 out of 5 based on 20 reviews from customers like you.

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

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

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

What are the hourly rates of extension builders in Castelnau?

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

Find extension builders in Castelnau with MyBuilder

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

Step 2: Compare different extension builders in Castelnau

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

Step 3: Hire Castelnau extension builders with confidence

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

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

What to ask a Castelnau extension builder before hiring?

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

An extension builder in Castelnau 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 Castelnau 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 Castelnau?

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 Castelnau 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 Castelnau 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 Castelnau

Can an extension builder in Castelnau help with planning permission?

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

Many Castelnau 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 Castelnau help with materials and finishes?

Yes, most extension builders in Castelnau 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.