Holbein Gardens located between 1 Sloane Gardens and Tarnbrook Court in London’s Royal Borough of Kensington and Chelsea, U.K., originally dates back to the 1980s and has been repurposed to provide high quality, flexible and sustainable workspace in the heart of London. Alongside the restoration of the existing four stories, there will be an extension to the rooftop, with an additional fifth floor and terrace, bringing the size of the project to 25,000 square feet.

The project is one of the City’s most sustainable office buildings, net zero carbon has been achieved in line with U.K. Green Building Council’s Net Zero Carbon Buildings Framework. Receiving the prestigious Wastebuild Zero 2023 Award, in the Commercial Building Category, Holbein Gardens has been recognized as a leading example of how to refurbish existing office stock, whilst delivering net zero ambitions. 

Appointed as building services engineers, the team was responsible for the mechanical, electrical and public health engineering. HDR was also responsible for the vertical transportation and energy strategies. We also designed the building to be Smart Ready, thus futureproofing Holbein Gardens to adapt to future technologies.

Clean and Renewable

Our expert team of energy and sustainability engineers were instrumental in ensuring that this building achieved BREEAM Outstanding, WELL Gold and Wired Score Gold certifications, with aspirations for Platinum. The scheme is also a NABERS pioneer project; striving towards net zero targets, with 99.95% of strip out waste having been diverted from landfill. The all-electric building maximizes heat pump technology, lending itself to decarbonization while also being beneficial for local air quality, minimizing air pollution.

Sustainable Materials

Biodiversity is at the heart of this project and a range of innovative materials and technologies have been used to achieve the greatest positive impact. Cross-laminated timber has been used in the extension, as an alternative to other materials, helping to reduce carbon emissions and restoration of forest, alongside reclaimed steel work. New low embodied carbon products are also being trialled in the building, such as Thermalite aircrete blockwork and reclaimed access flooring.

Biodiversity and Ecological Resiliency

Holbein Gardens has incorporated the use of biophilia and greening to ensure the biodiversity and resiliency of the site, while also positively contributing to the environment of the surrounding area, namely Belgravia.

A Façade with a Purpose

Another sustainable practice that has been adopted for the project, is to retain existing materials. By repurposing the façade, this approach has ensured that the project will save 39% of embodied carbon, compared to the use of all new materials.

The new roof terrace will also make an addition to the existing exterior, providing tenants with iconic vistas to Royal Borough of Kensington and Chelsea towards the west and Westminster to the east. To optimize usable space on the roof terrace, our engineers maximized the use of plant within the basement. The scheme also includes roof-mounted plant, which helps to service photovoltaic panels.

Mixed-Mode Ventilation

Our team has interfaced new windows with a roof-mounted weather station via the building management system to facilitate natural ventilation. Local displays will indicate optimal environmental conditions for office workers to open the windows, as well as to reduce electricity consumption through reduced reliance on mechanical systems, which turn off to minimize energy consumption, all contributing to our client’s sustainability goals.