Philippe Rahm: Understanding Light in Order to Master It

From the Split Time Café to the Jade Eco Park: Light Between Experimentation and Construction

Today, we have chosen to focus on Philippe Rahm, an architect and theorist who has transformed natural light into a living material—one capable of shaping emotions and rhythms, turning the invisible into architecture.

Rahm does not simply design spaces; he designs bodily reactions. He creates environments that manipulate temperature, colour, atmospheric composition, and light intensity, leading us to perceive a time, condition, or energy that does not actually exist. It is a form of “physiological deception” in the noblest and most experimental sense of the term: a way of revealing—through controlled alteration—the potential of light as a tool for understanding the body, space, and sensory experience.

Split Time Café

Among his most emblematic works is the Split Time Café, designed in 2007 but built ten years later within Taichung Central Park in Taiwan. Today, it is known as the ORES Café & Gallery.

The project began as an experiment investigating the influence of light on circadian rhythms. Rahm divides the café into three areas corresponding to three different luminous temporalities, each capable of affecting the secretion of melatonin—the hormone that regulates sleep and wakefulness—in a different way.

The First Room

The first room, immersed in natural light filtered through transparent glass, follows the actual cycle of the day, restoring a sense of vital energy.

The Second Room

The second room, enclosed by a shell of yellow glass, filters out the blue component of light, softening it and inducing a sense of calm, as though it were a clear and peaceful night.

The Third Room

In the third room, enclosed within a shell of blue glass, the sensation is reversed: cool light waves keep the body in a constant state of alertness, suspending time in a perpetual day.

During the short journey through the three rooms, visitors experience different psychophysical states, discovering how light can orchestrate both architecture and physiology. Rahm does not build walls, but “days”: spaces that translate biological language into architectural experience.

Jade Eco Park

With the Jade Eco Park (2011–2020), later renamed Taichung Central Park, in Taichung, Taiwan, this same idea expands to an urban scale.

Across 67 hectares of land, Rahm designed a landscape of microclimates in which slopes, vegetation, and materials modulate light, wind, and temperature. The park becomes an educational ecosystem where natural light regulates comfort and perception: the colours of the vegetation transform the tone of the light, shadows move like atmospheric brushstrokes, and the soil and tree species control ventilation and humidity.

Walking through the park means moving through a living organism in which light is not decoration, but ecological infrastructure—an educational tool for understanding the relationship between the body and the climate.

Knowledge Is Born Through Experimentation

From the Split Time Café to the Jade Eco Park, Rahm’s journey expresses a single principle: knowledge is born through experimentation.

Designing with light requires method, curiosity, and practical sensitivity—the qualities of the designer-craftsperson who observes, measures, and listens before composing.

Teaching light today means restoring this experiential dimension. Alongside theory and digital models, direct practice is essential: observing natural light, experiencing visual fatigue, and perceiving changes in time or mood.

Only through experimentation can lighting design bring together science, biology, and personal sensitivity, transforming technique into language and architecture into experience.

Philippe Rahm teaches us that light can only be mastered by understanding it, and that every project is, ultimately, an act of freedom: transforming the invisible into something that can be experienced.

The Beta Nit team would like to sincerely thank Architect Philippe Rahm for his technical contribution and Crystal Cheng for allowing us to use her beautiful photographs of the café and the park, published on her fascinating blog, auntie.tw.