Lighting The Cathedral: HSBC’s atrium reimagined

A lighting scheme by Mindseye Lighting and Illumination Physics celebrates the soaring atrium of Foster’s iconic HSBC building in Hong Kong.

The main banking hall of HSBC’s headquarters in Hong Kong is referred to as ‘The Cathedral’ for good reason; the modern resemblance to a grand abbey is undeniable. This vast space soars above the glass floor of the main banking hall and is accessed via escalators from the plaza below. The vaulted ceiling is crowned with the sparkle of an immense mirror. The office floors are the galleries and the bridges the cloisters. The eastern elevation contains a grand symbolic gesture, a vast unstained glass window complete with its tracery of mullions and transoms, which extends the full height of the vault.

Now this glorious space boasts a lighting scheme designed by London-based consultant Mindseye Lighting. The impetus to develop and implement the concept came from the 150th anniversary of the Bank this year. The design has been realised by Illumination Physics; the pair have also worked together on the replacement of all external lighting and the creation of three large media walls.

All fixtures are RGB and DMX programmable. The team created content for a variety of dynamic displays that are synchronised with the Sunscoop and atrium edges.

There is much that is unique about Foster’s 1985 example of ‘Structural Expressionism’. If the first view of the building is arresting, the internal design is just as fascinating. With no internal core structure, the building is suspended from the steel exoskeleton and the services are hung from this using bridge building techniques.

Foster was able to create a spectacular atrium that soars 55 metres upward from the glass floor of the main banking hall; itself suspended 10 metres above the ground so that an open public plaza can exist at street level. The bank’s customers ride up through the transparent belly of the building via the world’s longest free-standing escalators.

The atrium is 11 stories high. Mounted at the top are a bank of giant mirrors designed to reflect natural light being captured by the computer-controlled ‘Sunscoop’, a massive articulated reflector mounted on the exterior of the south façade.

Sadly, the proliferation of new skyscrapers has rendered this device largely ineffective today but if you are lucky enough to be present on a day when the light strikes the Sunscoop, you will witness these magical mirrors come to life, even if just for a brief moment.

At the centre of the eastern façade is the ‘Cathedral Wall’. This 50-metre high double layer glass wall is transparent on the outside but opaque on the inside allowing natural diffused light to enter which exposes the remarkable metal structure.

The lighting concept was decorative and conceived of the use of a mix of direct-view lighting and back-lit panels. The areas to be treated included the chamfered edges of the floors that surround the atrium, the Sunscoop mirrors and the Cathedral Wall. “The idea was to create a stained glass feature of the Cathedral Wall, to treat each panel as a stained glass element,” says Admir Jukanovic, associate at Mindseye.

The Cathedral Wall’s inner glass layer was illuminated from within the cavity whilst keeping the light fixtures and cables invisible. “Our objective was to illuminate each 1200mm pane of glass individually, creating a pixel,” says Illumination Physics.

“Creating an internally illuminated light box on the chamfered floor edges proved problematic for structural reasons,” says the company. “Indirect grazing light produced obvious aberrations because of the slight differences between the metal panels.”

This is always a problem even with the best quality cladding. Mock-ups and testing found that a direct view LED strip with a 100% diffused lens would produce the best result. Illumination Physics developed a custom version of its IP Bar rectilinear fixture. An IP Bar rail was also created to hold the IP Bar. The clean lines emphasise and support the architecture and add spectacle and drama to the space.

Previously the upper levels of the atrium were regarded as too dark and the addition of the line of light on each of the five floors which bound the atrium corrected that impression.

All fixtures are RGB and DMX programmable. The team created content for a variety of dynamic displays that are synchronised with the Sunscoop and atrium edges. Given that the Cathedral Wall is not activated until early evening, lower power LED is sufficient.  “During the day, we keep things neutral but when people start to leave the office, that’s when the show starts, both outside and inside,” says Jukanovic.