WI Leibniz Institut, RWTH Aachen

WI Leibniz Institute – RWTH Aachen University, Germany
Project overview

The WI Leibniz Institute at RWTH Aachen University is a research facility that required precise daylight control to support scientific work. The building includes offices and laboratories, with large windows to foster communication and collaboration. The design emphasised simplicity and automatic operation to avoid distracting researchers.

Design challenge

The institute’s offices face different orientations, necessitating tailored shading strategies. Researchers needed stable lighting conditions to work at computers, read printed materials and perform experiments. Manual operation of blinds would be impractical, and external shading was not desirable due to maintenance concerns. The system had to be responsive to daily and seasonal changes in the sun’s position.

RetroSolar strategy

The building employs interior RETROLux 50 mm blinds mounted in vertical shafts
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. A central control system automatically adjusts the slat angles based on solar geometry. For low sun angles below 30°, the slats remain horizontal, preserving outward views. When the sun rises higher, the slats tilt to reflect light onto the ceilings. The control is facade‑specific, taking into account orientation, and a sun sensor triggers operation only when direct sunlight strikes the façade. This approach reduces unnecessary movement and extends the lifespan of the blinds
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.

Building physics and performance

The reflective slats reject direct sunlight before it enters the room, reducing heat gain and glare. By maintaining a horizontal orientation at low sun angles, the system ensures that the blinds do not obscure the view, which is particularly important for researchers seeking visual relief. The automation also prevents user error, delivering consistent performance across the building. The resulting daylight is evenly distributed, and artificial lighting can be minimised during daytime hours.

Architectural outcome and significance

The WI Leibniz Institute benefits from a comfortable and productive working environment. The automatic RetroSolar blinds allow researchers to focus on their work without adjusting shading devices. The system’s reliability and unobtrusiveness make it well suited to research facilities and demonstrate how retro‑reflective technology can be adapted for automated operation. The project adds to the portfolio of RetroSolar installations at academic institutions, underscoring the technology’s versatility.