CIRCA DIEM: Seoul Biennale of Architecture and Urbanism 2021

Seoul, September 2021

The CIRCA DIEM project is developed by EPFL and HEAD – Genève for the Seoul Biennale of Architecture and Urbanism 2021. The installation raises awareness about the impact of our daily exposure to light and its dynamics in dense urban environments, which becomes even more important when considering underground life. Circa diem – “about one day” in Latin – is at the origin of what we call our “circadian rhythms” and suggests here a deep and essential link with the natural day-night cycle.

Light regulates our neurophysiology according to the natural day-night cycle and thus profoundly affects the liveability of dense cities, in which we tend to live increasingly indoors and deeper underground. Architecture and the urban fabric have the ability to control our access to natural light and do so by redirecting light rays through spatial form. By entering Circa Diem, the visitor gets a sensorial experience of the passing of time through four phases of the 24-hour day—morning, midday, evening and night—thanks to a dynamic choreography of light and dark, color, words, and images alluding to the multiple dimensions of circadian rhythmicity in the built environment.

The Seoul Biennale of Architecture and Urbanism 2021 (SBAU) is the first global architectural event entirely produced following a pandemic that has altered and challenged the foundations of our civilization. Entitled “CROSSROADS Building the resilient”, it intends to gather different forms of intelligence to reflect on the city of the future as a more sustainable, resilient and comfortable place for its inhabitants. The exhibition is hosted in the Dongdaemun Design Plaza designed by Zaha Hadid in Seoul, South Korea


Project Leaders:

Marilyne Andersen, EPFL

Mark Pauly, EPFL

Javier Fernández Contreras, HEAD – Genève

Florin Isvoranu, EPFL


Alice Proux, HEAD – Genève

Megan Danell, EPFL


Image Credits © 2021 EPFL / Alain Herzog – CC BY-SA 4.0