ONE, Frankfurt

ONE Tower – Frankfurt, Germany
Project overview

The ONE tower is a 49‑storey mixed‑use building in Frankfurt’s Europaviertel district, completed in 2022. Designed by Meurer Generalplaner for the developer CA Immo, the 190 m high tower houses offices, a hotel and public amenities. Its slim, crystalline form contributes to Frankfurt’s rapidly evolving skyline. Selected interior spaces, such as the entrance foyers and the skybar at the top, required elegant daylight control to enhance the user experience without interfering with panoramic views.

Design challenge

Within the high‑rise, spaces such as foyers and hospitality areas benefit from large glazed surfaces to accentuate views of the city. However, these areas also face issues of glare when the sun is low on the horizon and of excessive heat from direct sunlight. Conventional blinds would detract from the interior design and obstruct the vistas that are a key selling point of the building. A subtle, high‑performance shading solution was needed.

RetroSolar strategy

The developer selected RETROFlex louvers for targeted interior sun protection. Because RetroFlex louvers have a fine micro‑structure and high translucency, they can remain in an open position without appearing as a visual barrier. The mirror surfaces retro‑reflect direct sunlight, while the lower surfaces allow occupants to see through the blinds. This solution was installed in the ground‑floor foyer and skybar, areas where design quality and views are paramount. Construction of the tower took place between 2018 and 2022, and the shading system was integrated seamlessly into the interior fit‑out.

Building physics and performance

The retro‑reflective louvers prevent glare and reduce solar heat gain in the critical public areas of the tower. By reflecting light back out, they minimise the temperature rise of the interior surfaces and help maintain a pleasant climate. The high translucency ensures that the blinds do not visually dominate the space even when deployed. This passive approach supports the building’s overall sustainability credentials, which include advanced façade performance and energy‑efficient systems.

Architectural outcome and significance

Inside the ONE tower, the RetroSolar blinds contribute to a sophisticated atmosphere in the lobby and skybar, allowing occupants to enjoy expansive views of Frankfurt without discomfort. The integration of this technology into a high‑rise mixed‑use building illustrates the versatility of mirror‑optic shading systems beyond typical office applications. The project underscores CA Immo’s commitment to innovative environmental solutions and positions the ONE tower as a benchmark for sustainable skyscrapers in Europe.