Info & Images: Courtesy UNStudio
UNStudio’s design has been selected as the winning entry in the competition for the remodelling of the Hanwha headquarters building in Seoul.
Putting strategic emphasis on renewable energies as its future growth engine, Hanwha Group, the world's third largest photovoltaic producer, wanted its headquarter building to reflect its vision and mission. The competition’s winning entry has remodelling by UNStudio; Arup as the sustainability and facade consultant; Loos van Vliet as landscape designer and AGLicht joined as lighting consultant for the interior, landscape and facade lighting.
Located on the Cheonggyecheon in Seoul, the 57,696 sq.m. headquarter building will incorporate remodelling of the facade, interior of the common spaces, lobbies, meeting levels, and auditorium and executive areas, along with the redesign of the landscaping.
The design is guided by the surroundings, influenced by nature and driven by the environment, with an integrated responsive facade as the key stand-out factor, which improves the indoor climate of the existing building and reacts to both the programme distribution and the location.
The existing façade contains horizontal bands of opaque panelling and single layers of dark glass. In the remodelling, this will be replaced by clear insulated glass and aluminium framing to accentuate views and daylight. The geometry (pattern, size and reveal) of the framing is further defined by the sun and orientation factors to ensure user comfort inside and reduced energy consumption.
The North facade opens to enable day lighting within the building but becomes more opaque on the South façade, where the sun would otherwise have too much impact on the heat load of the building. Openings within the facade are further related to the views: opening up, where views are possible but becoming more compact on the side adjacent to the nearby buildings.
Further, direct solar impact on the building is reduced by shading, which is provided by angling the glazing away from direct sunlight, while the upper portion of the South facade is angled to receive direct sunlight. The window-to-wall ratio is taken into account in order to achieve 55% transparency across the entire facade, while PV cells are placed on the opaque panels on the South / Southeast facade at the open zones, where there is an optimal amount of direct sunlight. Furthermore, PV panels are angled in the areas of the facade, where energy from the sun can best be harvested.
The basis for the facade expression is to achieve an effect of variety, irregularity and intricacy throughout the facade. This is approached by combining a system of multi-scaled elements in a simple fashion and is additionally informed by the programme. By varying the placement of the facade panels, a variety of programme-related openings are created, with the result that the restaurant, the executive room, the sky gardens, the seminar spaces etc. are all expressed in the facade.
This is further enhanced by animated facade lighting. In the evenings, as the mass of the building becomes less apparent, the facade lighting integrates with the night sky, displaying gently shifting constellations of light.