Rejuvenation of heritage buildings breathes new life into forgotten corner of London

The retained façades of forgotten warehouses blend sensitively into a new development providing elevations to two 6-storey office buildings. Schüco Jansen thermally broken steel windows and doors were chosen to replace the original thermally inefficient steel windows, and for the glazing in the new long elevation.

Inspired by the Victorian terraces bounding its Stoney Street site, the façade of the new building incorporates a series of folds that respond to the rhythm of the townscape.

The warehouses’ original windows acted as a blueprint for the new window design as planning dictated that the elegant, slender sightlines should be maintained. The Schüco Jansen systems enabled the retained façades to maintain their historic appearance while making them thermally efficient, contributing significantly towards the achievement of a BREEAM Excellence rating for the office building.

Lloyd Bennett, Director at Propak Architectural Glazing, explains why Schüco was specified for the project: “The thermal performance and fire rating of the glazing was key to bringing the building up to modern standards. The high security entrance doors, large span glazing to the upper floors and 10-pane bifold doors also had to seamlessly mirror the style of the original windows which made for a challenging design process.

“The Schüco Jansen Arte 2.0 steel windows and Janisol steel door systems were an ideal fit as their sleek sightlines meant they could sensitively blend into the heritage Victorian brickwork and gothic arches. The system also possessed the structural strength to deal with the floor to ceiling glazing, a key feature of the office spaces.”

The Schüco systems met the requirement for the glazing to be fire rated to the highest standard while still letting in light. The high security doors were also required to meet the DOCO requirements. The top-class, 10-pane Janisol bifold doors, which are 8 metres long and thermally broken, were tested at BRE by Propak to achieve PAS24:2016 Annex A&B. All entrance doors were also tested and were manufactured from Janisol thermally broken steel doors to match the bifold doors.

The energy efficiency of the building was another consideration, and a passive design solution was implemented. The minimal sightlines of the Jansen Arte 2.0 profiles combined with high performance solar control glass allow large amounts of sunlight to pass through the windows, while at the same time reflecting away much of the solar energy, helping to keep the building cool. This reduces the need for air conditioning and interior lighting resulting in an energy efficient building that is brighter, cooler and flooded with natural light.

The project presented a number of challenges. Where possible original features were restored, however some were beyond repair and were sent to recycling. The I-beams framing the windows between floors fell into this bracket and new replica I-beams were manufactured as part of the window system. The new I-beams were not structural which meant the fixing points had to be moved further away from the windows. This in turn made the engineering and installation complicated.

The works were located in a highly built-up area with restricted access and high footfall through Borough Market, resulting in a logistically challenging delivery and installation process. The Propak project team worked closely with the main contractor to strategically move large span glazing in and around the tight working conditions.

Borough Yards is a fine example of how adaptable Schüco Jansen steel systems are; structurally robust for high usage and high security areas, ideal for the environment due to their excellent thermal performance, strong enough to house large span glass, and perfect for heritage buildings due to their slim sightlines.