Dutch architects UNStudio have recently completed the top-to-bottom renovation and re-skinning of an existing office tower in Seoul for corporation company Hanwha. 

The eye-catching project is notable due to the fact that the extensive renovation and re-cladding were executed while the building remained occupied by the company and its workforce. According to a press release describing the project, construction teams worked three floors at a time, starting at the ground floor lobby and surrounding landscaped spaces and moving up to the tower's new top-floor restaurants and office suites. 

Gansam Partners served as the Executive Architect while Loos van Vliet provided landscape design services for the project. Additionally, ARUP Hong Kong provided facade and sustainability expertise and AG Licht acted as lighting consultant.

For the project, UNStudio replaced an aging, inefficient single-pane glass curtain wall envelope with new aluminum framed insulated glass assemblies marked by customized and variable solar shading elements. 

According to the architects, "Addressing the request that the design be guided by the surroundings, influenced by nature and driven by the environment, UNStudio developed an integrated responsive facade concept which improves the indoor climate of the existing building and reacts to both the program distribution and the location."

In a press release supporting the project, UNStudio co-founder and principal Ben van Berkel writes, “By means of a reductive, integrated gesture, the facade design for the Hanwha HQ implements fully inclusive systems which significantly impact the interior climate of the building, improve user comfort and ensure high levels of sustainability and affordability. Through fully integrated design strategies today’s facades can provide responsive and performative envelopes that both contextually and conceptually react to their local surroundings, whilst simultaneously determining interior conditions.”

The tower's highly articulated facade features open window modules along the tower's northern facade, where natural daylight can enter the building's workspaces. 

Along portions of the tower that face nearby buildings and throughout the building's southern exposure, the exteriors are marked with solar shades and other opaque elements to limit heat gain. The solar shades along the southern facade are topped with solar panels that help generate energy for the office tower.