Sustainability Award

Designed by Barr Gazetas, Holbein Gardens is a redeveloped and extended 1980s commercial building located near London’s Sloane Square. Rated BREEAM Outstanding, the all-electric scheme provides 2,300 square metres of high-quality office space and includes retention of the existing façade, together with the introduction of full-height glazing and balconies, as well as extensive landscaping to increase biodiversity and employee wellbeing. In addition to reducing upfront carbon emissions, the building’s passive design strategy incorporates exposed concrete slabs for improved thermal mass, mixed-mode ventilation, on-site renewable energy generation, and blue roofs.

Schüco AWS 90.SI windows were specified throughout for their outstanding thermal performance, achieving an average weighted figure of 1.2 W/m²k – impressive given the building’s high volume of opening lights. Generously-sized and thermally-efficient Schüco ASE 67 PD and ASE 80.HI sliding door systems provide excellent daylighting and panoramic views across the city.

Specialist contractor Glass Box Facades was appointed to design, manufacture and install the Schüco windows and doors. It conducted a detailed site survey of the existing openings prior to design and manufacture, ensuring accurate installation and the prevention of thermal loss due to poor detailing. Large slimline sliding doors employed on the fifth floor were manufactured to the highest standards and installed with great care to ensure smooth operation over the coming years.

The judges were highly impressed by the project team's carefully considered façade retention strategy, and the key role played by Schüco window and door systems in ensuring the building’s long-term environmental performance.