For a good 340 years, the Hamburg Chamber of Commerce (Handelskammer) has been not only the central stock exchange and hub of the city’s economic life, but also a place of great social importance. Situated close to major city landmarks, this building and the City Hall together comprise the oldest classical architectural ensemble to have survived in the city.
Due to the increased use of modern information and communications technology, space for new usages had become available in the stock exchange, the ‘Börsenhalle’. A business start-up center, consultation, exhibition, club and meeting room facilities for members, guests and visitors are arranged in a sculptural manner. The uppermost level affords access to generous roof terraces and beautiful views out over the roofs of Hamburg through a band of arched clerestory windows.
In consideration of both the structural condition of the listed ‘Börsenhalle’ building and the mandatory preservation of its historical features, a new 5-storey structure was inserted into it: a ‘house within a house’ that comprises circa 1,000 sq.m for new usages. The Chamber of Commerce had initially envisaged only a 3-storey inner extension of the original structure, yet the dimensions of this would have covered the hall’s entire ground floor surface area. In close collaboration with the client, the architects therefore proposed a 5-storey structure with a much smaller footprint, which would instead exploit the hall’s height.
The structure unfolds as seemingly free-floating levels and planes that consciously contrast the historic hall’s ponderous stone bulk: here, the soft lines of vaulted constructions, there, the clear lines of the new structure: a bright apparition constructed of luminous, transparent and reflective materials, reminiscent of a glittering, multi-faceted jewel that absorbs and refracts light.
Translucent construction elements and silvered lamella produce trompe-l’oeil effects and remarkable dimensions: impressions that suddenly shimmer, seeming at moments to be almost unreal, and culminate in a fluid explosion of space, attained by the use of lighting comprised of fields of square LED modules set into the ceilings. Elements of the original hall are incorporated as reflections in the new spaces, whilst the actual connection of ‘Haus im Haus’ to its older surroundings remains hidden. The ‘Haus im Haus’ is the first structure in the world that is completely lit by LED lamps.