Extension Builders in Kings Cross

Name: Extension Builder
Brand: MyBuilder
SKU: extension-builder
Rating: 4.1 (19 reviews)

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Some of our top rated extension builders in Kings Cross

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Koncore Plumbing & Heating Ltd
Rating: 5 out of 5
Extension Builder in Kings Cross
*PLEASE ONLY SHORTLIST US IF YOU ARE HAPPY WITH OUR QUOTE* We have many years of experience and, as such, have seen almost every imaginable plumbing and heating emergency that you can imagine, and we can fix them all. We aim to fix every problem on our first visit, in the fastest time possible. NO JOB TOO BIG OR TOO SMALL, WE DO IT ALL!!
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Latest review:
Gas Work- 27 Jun 2026
Good job
Macondo Carpentry Ltd
Rating: 5 out of 5
Extension Builder in Kings Cross
Welcome to Macondo Carpentry Ltd, your trusted partner for all carpentry and building needs in North London. With a commitment to craftsmanship, quality, and customer satisfaction, we specialise in transforming your visions into reality. Whether you’re looking to renovate your home, create bespoke furniture, or undertake a complete building project, our skilled team is here to provide exceptional service and impeccable results. At Macondo Carpentry, we pride ourselves on our attention to detail, use of high-quality materials, and dedication to sustainable practices. Contact us today to discuss your project and discover how Macondo Carpentry can bring your ideas to life. Jobs we specialise in- Kitchens Bathrooms Refurbs 1st & 2nd fix carpentry Tiling General building work
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Latest review:
Carpentry- 28 Oct 2024
Jesse is efficient. Will defo use again.
Su Su Construction Limited
Rating: 5 out of 5
Extension Builder in Kings Cross
Welcome to Susu Construction: Your Premier London Construction Partner Are you searching for a London construction company that stands out for its excellence, commitment, and innovation? Look no further than Susu Construction, your go-to choice for top-notch construction solutions in the bustling capital of London.
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Latest review:
Groundwork & Foundations- 2 Dec 2022
We are very happy and glad to have found Su Su Construction. It is great to work with such an open minded contractor who is very experienced and diligent. To us architects it is really important to be able to explore alternative means of construction in order to create long lasting, beautiful and healthy environments and with SuSu we are on the right track. Highly recommend.
London & Kent Best Kitchen & Bathroom Solutions Ltd.
Rating: 5 out of 5
Extension Builder in Kings Cross
Our highly skilled team of builders, carpenters, electricians, decorators and plumbers are reliable, trustworthy and dedicated to achieving the highest quality finish for your project; however large or small. Each project is tailored to your requirements and managed via a single point of contact.
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Latest review:
Bathroom Fitting- 26 Nov 2020
Sylwester and team did a fantastic job and were incredibly accommodating and polite with all of our requests. Would definitely recommend.
H&J Properties 02 Ltd
Rating: 5 out of 5
Extension Builder in Kings Cross
H&J Properties is your friendly, reliable small team with over 10 years of experience in the building industry. We design, plan, build, and project manage, so you can rely on us for a full round of service. From floor and wall tiling to full kitchen and bathroom installations, we’ve got your home covered. We handle plastering, painting, drylining, insulation, and more with precision and pride. Need a loft, rear or basement extension, a new roof, or concrete work? No problem. Whether it’s bricklaying, basement waterproofing, or installing windows and doors, we bring craftsmanship and care to every job. Big or small, we build it right. Please message us directly for more project images.
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Latest review:
We have contracted H&J Properties for our house refurbishment in London. I was impressed with the team's professionalism and project management from start to finish. We had no plans or planning approved, so we wanted a design and build company who will be able to look after the project from start to finish. They did just that. Working with the architects and the planning application before starting the project planning. As always, there are, of course, unforeseen issues arising with the old houses in london but I could't be happier with the communication received from the team. Thanks for the great job.
LEBELLE HERITAGE & RESTORATION LTD
Rating: 5 out of 5
Extension Builder in Kings Cross
Lebelle Heritage & Restoration Lebelle Heritage & Restoration is a professional building and construction company specialising in renovations, refurbishments, and heritage restoration. We take on all types of projects, from full property renovations and structural upgrades to detailed interior finishes and the careful restoration of period features. Our team is skilled in both traditional craftsmanship and modern construction methods, allowing us to deliver work that is reliable, high-quality, and built to last. Whether we’re restoring the character of an older property or breathing new life into a modern home, we focus on precision, honesty, and clear communication throughout every stage of the job. We pride ourselves on delivering clean, efficient, and well-executed work that meets the needs of our clients and respects the integrity of each building. At Lebelle Heritage & Restoration, we build, renovate, refurbish, and restore with a commitment to quality and long-term durability.
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Latest review:
After a previous contractor took our money and left our loft extension unfinished, we were devastated and worried about how we would ever get our home back to normal. Then Lewis from Lebelle stepped in and completely turned things around. Lewis was patient, understanding, and incredibly professional. He worked quickly, kept costs under control, and finished the loft extension to a standard we’re so happy with. The stress he took off our shoulders was unbelievable. We honestly can’t thank Lewis enough. If you’re looking for someone trustworthy, skilled, and genuinely caring, Lebelle is the company to call.
Signature 1 Construction Ltd
Rating: 4.5 out of 5
Extension Builder in Kings Cross
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.
KML BUILDING (UK) ltd
Rating: 4.5 out of 5
Extension Builder in Kings Cross
KML is a Central London-based building company with a strong reputation for quality, reliability, and attention to detail. We specialise in home extensions, refurbishments, HMO conversions, and general building works — providing tailored solutions for both residential and commercial clients. As a small, hands-on team, we offer a personal service from start to finish, ensuring every project meets the highest standards of craftsmanship and compliance.
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Latest review:
Bathroom Fitting- 13 Oct 2025
Camilo was supposed to meet me today to give me a quote. He missed our appointment without any notification. I am not here to chase people to do their job. The job will be advertised again, as he was not hired.
TPR Builders
Rating: 5 out of 5
Extension Builder in Kings Cross
I have worked as a builder for the past seventeen years in London. I have done many projects ranging from lofts and extensions, I have gained experience over the years. My goal is to work in my local area.
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Latest review:
Kitchen Fitting- 29 Nov 2025
Pawel did a great job replacing a roof light and repairing two walls on our home office - an efficient, reliable and knowledgeable contractor.
City Building and Roofing Ltd
Rating: 4.9 out of 5
Extension Builder in Kings Cross
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.
Nami Construction Ltd
Rating: 5 out of 5
Extension Builder in Kings Cross
We offer comprehensive property refurbishment services that include decorating, plumbing, electrical work, plastering, extensions, and loft conversions. Our team comprises professionals, and we ensure that all instructions are regularly reviewed with our clients throughout the duration of the project. We provide transparent and detailed estimates and updates on a regular basis to help you control your budget. Our services cater to all types of homes, such as those owned by landlords, Thank you
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Latest review:
Plumbing- 19 May 2026
Emir did a good job. The company did a bathroom refurbishment after water leak, repaired the damaged ceiling downstairs and painted the room. Emir’s attention to detail is very good and he went the extra mile to do the job properly. I will recommend his services.
LDN Construction
Rating: 4.6 out of 5
Extension Builder in Kings Cross
With over 20 years of experience, we specialise in loft conversions, roofing, extensions and more. We primarily operate in Greater London, Our team possesses diverse skills and knowledge, ensuring top-quality results. We take pride in delivering exceptional customer service, professional workmanship, and thorough aftercare. Choose us for your next project and experience the best in the business.
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Latest review:
Bathroom Fitting- 28 Nov 2024
in my place, everything looks fine. but they used long screws penetrated the downstairs pipeline, which made my life very hard, intense relationship with neighbors, neighbors tries to break in. and this problem is still going on. i don't know how to fix it.
PACHO CREATE LTD
Rating: 5 out of 5
Extension Builder in Kings Cross
Pacho Create specializes in high-quality loft conversions, home extensions, and full refurbishments—transforming homes into beautiful, functional spaces. With a focus on craftsmanship, planning, and client satisfaction, we bring your vision to life on time and on budget. Let me know if you want a more premium, modern, or friendly tone.
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Latest review:
Tiling- 24 May 2026
I cannot recommend John from Pacho Create Ltd highly enough. I'm a very particular client with high standards, I was impressed by his care, patience, and professionalism throughout. He clearly takes pride in delivering quality work and paid close attention to every detail. Living in a small flat, I was concerned about dust, but John proactively created a solution to minimise disruption, which I really appreciated. He also gave excellent advice on budget-friendly waterproofing products. We had a challenge with large-format tiles, but John worked closely with me to plan the layout, ensuring a natural, balanced finish. The workmanship is outstanding – minimal wastage, precise alignment, and superb attention to detail. I wouldn’t hesitate to use John again, in fact, I’m already planning to have him back to tile around my bath in the near future. I highly recommend him to anyone looking for a skilled, reliable professional.
Mark's Amazing Building Company
Rating: 5 out of 5
Extension Builder in Kings Cross
Mark and his team of 8 have over 100 years of trade experience between them. Each member of the team has honed their craft in a specific trade from bricklaying to plastering, extensions to renovations. Working so close to each other and as a team, they create extensions and renovations to a high standard and always work on one job at a time to ensure a finish of high standards.
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Latest review:
Mark and his team did an amazing job on our extension. We will shout it out from the rooftops. They walked us through all aspects of the build and where so friendly and clean. If we ever extend anything else we will look them up.
First Int. Project Limited
Rating: 4.4 out of 5
Extension Builder in Kings Cross
Back on MyBuilder after 7 years !!! Design and build Architectural team Structural engineers team Build and construction Our business is based on TRUST | QUALITY | CARE Our company cover the following trades: -steel erecting - steel structures -roofing - loft conversions -plasterers - internal skimming -painters and decorators -kitchen installers -bathroom fitters -bricklayers - for extensions -landscapers -electricians -gas engineers -carpenters - floor, doors, structural -windows installers -bespoke furniture
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Latest review:
Bathroom Fitting- 15 May 2017
We hired Inside/Outside to re-do our bathroom. New sink, bath, toilet, tiles, lower ceiling, re-hang the door and move the radiator. They were polite, honest, professional and very hard working. When they came round to quote they were noticeably more thorough and showed more attention to detail than others. Their quotes were very competitive, their work was good and they removed all the rubbish as well. They also came back afterwards to check everything was working and to deal with a couple of 'snags'. We will be using them again.
Zardi Construction LTD
Rating: 5 out of 5
Extension Builder in Kings Cross
Zardi Construction LTD is a knowledgeable and experienced construction company . We are focusing on property renovation loft conversion, extension bathroom, kitchen and refurbishment service. Our workers are skilled . we have ours own carpentry joinery and cabinetmaking workshop to achieve best quality for our customers . We are committed to giving our customers the best quality and results every time. Best regards zardi
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Latest review:
Restoration & Refurbishment- 8 Oct 2018
Hassan has been very patient and thoughtful throughout the refourbishment of our flat. We had an entire new kitchen and bathroom fitted plus some walls removed. I would definitely recommend his services. The flat was left clean with good finishing details.

4.1

Top rated Extension Builders

Our Extension Builders in Kings Cross, are rated 4.1 out of 5 based on 19 reviews from customers like you.

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

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 Kings Cross 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 Kings Cross who are available and interested can respond to your post.

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

What are the hourly rates of extension builders in Kings Cross?

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

Find extension builders in Kings Cross with MyBuilder

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

Step 2: Compare different extension builders in Kings Cross

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

Step 3: Hire Kings Cross extension builders with confidence

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

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

What to ask a Kings Cross extension builder before hiring?

Before hiring an extension builder in Kings Cross or extension building company in Kings Cross, 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 Kings Cross?

An extension builder in Kings Cross 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 Kings Cross 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 Kings Cross?

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 Kings Cross 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 Kings Cross 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 Kings Cross

Can an extension builder in Kings Cross help with planning permission?

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

Many Kings Cross 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 Kings Cross help with materials and finishes?

Yes, most extension builders in Kings Cross 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.