When designing a new headquarters for Hanwha Group, a large Korean conglomerate, sustainability was among the company’s top concerns. The company, which is heavily involved in the renewable energy sector, wanted its 620,000-square-foot tower in downtown Seoul–built in the 1980s–to adequately reflect its position as a leading environmental technology provider.

In response, Amsterdam-based UNStudio renovated the tower with a new, animated facade that lights up like a constellation of stars at night.

During the day, the facade is designed to optimize daylight and views while controlling the indoor climate. To reduce the energy necessary to maintain a comfortable temperature in the building’s interior, the facade varies in relation to where the sunlight is strongest. To reduce the building’s cooling costs, the architects made the southern side, which absorbs more sun than the northern side, more opaque, and kept the northern side more transparent. Glazing on the glass is angled to reduce the impact of direct sunlight, and photovoltaic panels rest on the southern facade to harvest solar energy.





These efficiency measures don’t come at the expense of aesthetics. The facade is animated by LED lights that can be programed to highlight specific areas of the building, whether that’s clusters of work spaces, the restaurant, the building’s gardens, or communal areas.

The dynamic lighting system, which can be adjusted to emit only a soft glow, is a subtle response to the very bright and busy signage of the businesses around it on Hanbit Avenue. “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,” Ben Van Berkel, co-founder of UNStudio, says in a press statement.