basement conversion Archives - Harris Calnan

Project Walkthrough: St John’s Wood, Low Carbon Renovation

Posted on ZXCZXC3 October 20253 October 2025 by FJDigital

We are pleased to share a video walkthrough of the early stages of our latest St John’s Wood renovation, delivered in collaboration with Architecture for London. Click on the video to learn more about this fantastic project.

The walkthrough shows the substantial temporary works now in place. We’ve installed steels and supports to extend the ground floor and secure the structure. This careful preparation allows excavation of the new basement to begin safely and efficiently.

This renovation will transform the existing house with a full strip out, a lowered and extended basement, and a high end fit out. Every stage of the build is guided by a low carbon, high efficiency approach, ensuring the finished home will be both elegant and sustainable.

Although the project is still at an early stage, the walkthrough highlights the scale of the work involved and the precision required. It offers an inside look at how complex residential projects are carefully managed from the very start.

We will continue to share updates as the project develops, giving further insight into each stage of this St John’s Wood renovation.

To see some of our finished finished projects, click here.

foundation works for substantial basement structure

New Build with Expansive Basement in St Albans

Posted on ZXCZXC24 September 202524 September 2025 by FJDigital

Harris Calnan recently delivered a striking new build residence in St Albans, following the full demolition of the existing property. The scheme involved the construction of a contemporary home complete with a large basement. This basement quickly became the defining feature of the project.

We usually focus on substantial developments across North London so the scale of the basement excavation made this project a perfect match for our expertise. Over the years, Harris Calnan has developed a strong record in complex basement works. Our experience covers deep excavations, specialist waterproofing and the careful coordination of services within tight structural constraints.

These skills allowed us to manage every stage with confidence and ensure the basement integrated seamlessly into the overall design of the home.

From groundworks through to completion, our team oversaw each element with care and precision. The result is a modern residence built to the highest standard, combining contemporary architecture with robust construction that will stand the test of time.

We worked alongside Neil Choudhury Architects on this project and collaborated with a skilled group of contractors and suppliers who contributed their craftsmanship and expertise.

If you would like to discuss an upcoming project with us, please get in touch.

Contact us
📞 020 8968 8877
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To see more of our projects please click here.

Luxury Residential Transformation, Ealing

Posted on ZXCZXC28 August 202528 August 2025 by FJDigital

At Harris Calnan, we are currently delivering a full residential transformation of a private property on Carlton Road, Ealing, working closely with Beasley Dickson Architects and Foster Structures. This ambitious scheme brings together our expertise in complex construction with a strong design vision, creating a contemporary home finished to the highest specification.

The works include a complete strip-out of the existing house, the formation of a new basement beneath the original footprint, a rear extension, and a new roof structure with coverings. We will complete the property with high-end finished throughout, all designed with an emphasis on low-carbon, high-efficiency performance supported by a ground source heat pump.

On site, we are pleased to be collaborating with Malci Construction who are progressing the basement works, AGA Scaffolding who have delivered the elaborate temporary works, and Maralb Construction who have completed the roof strip ready for inspection. Recent site meetings with the wider project team have allowed us to review progress in detail and carefully coordinate the next stages of the build.

From light-filled new spaces to a bespoke basement designed for modern family life, the property will not only reflect architectural excellence but also provide a comfortable, sustainable and future-ready home for years to come.

This project is a prime example of how we bring together skilled craftsmanship, collaborative working, and sustainable design solutions. Once complete, this residential transformation will combine architectural elegance with modern energy-efficient performance, reflecting both the ambition of the client and the expertise of the team.

See the gallery below to see some of the work in progress and if you’d like to see more of our recently completed projects, click here.

Progress Update: High End Renovation, Islington

Posted on ZXCZXC8 August 20258 August 2025 by FJDigital

Work continues to move forward at pace on our high-end renovation and basement extension project in Islington, where we’re delivering a complete transformation at 6 Highbury Hill.

Designed in collaboration with Cousins & Cousins Architects, this project includes a full strip-out of the existing property, a lowered and extended basement, and a high-end fit-out throughout. With Stuart Eley as Quantity Surveyor and Constructure as structural engineers, the team is pushing ahead with both care and precision.

Following recent progress on the basement shell, our in-house team has worked closely with Newton Waterproofing to ensure a robust waterproofing system is in place, ready for the installation of a polished concrete floor by Lazenby.

Externally, we’re restoring the original façade using a careful blend of new and traditional techniques, while above, the new roof is progressing well under full temporary cover.

A recent walk-around with the client and our site manager Brian provided a chance to review the ongoing work across every level of the home. With refurbished internals taking shape and the project moving into the next phase, this one is shaping up to be a standout example of collaboration and craftsmanship.

Most recently, we’ve also had the pleasure of working alongside Capital Rewire and Ember Lighting, who are supporting the next stage of internal works. This follows a visit from Estimus London, who installed the new slimline double glazed timber sash windows, now in place across the rear elevation.

Check out some of fantastic work in progress shots below to see the size of the incredible new basement space. We look forward to sharing more as the project develops.

To see more of our most recent work, please see our news page, and for completed projects and other high end renovations, check them out here.

Project Showcase: Luxury Renovation

Posted on ZXCZXC23 July 202523 July 2025 by FJDigital

Carlton Hill: A Luxury Renovation in St John’s Wood

Harris Calnan is proud to unveil the completion of a landmark project in St John’s Wood, a large-scale luxury renovation and basement conversion that showcases the very best of high-end residential construction.

Working alongside M W Architects and The Millbridge Group, this exceptional transformation involved retaining the original façade while completely rebuilding the structure behind, including the addition of a newly constructed basement.

The result is a home that seamlessly balances timeless architectural character with contemporary luxury. From the carefully curated materials to the uncompromising level of craftsmanship throughout, every detail reflects the quality and precision that Harris Calnan is known for.

The original façade of this period property was sensitively retained, preserving its heritage presence, while the entire structure behind was meticulously rebuilt. A newly excavated basement was added to increase living space and functionality without compromising on proportion or flow.

Inside, the property reveals a sophisticated and carefully curated interior palette. The formal sitting room is a masterclass in balance; fluted joinery and integrated lighting frame the bespoke marble fireplace, while soft furnishings in muted tones bring warmth and texture. Full-height Crittall-style doors lead from the hallway into the space, maintaining an open feel while providing elegant separation.

Carlton Hill reflects the collaborative expertise of an exceptional team, including those mentioned above but also Pringuer James, Blackburn & Co, Malci Construction, Maralb Construction, Haddonstone Ltd, Marble Bros, The Blacksmiths Shop, Calin Metals, CMD Bespoke, LDN Leadwork, Glazing Vision, VELUX, IQ Glass, Perla Windows, Domus Tiles, Salisbury Joinery and the Norden Group.