Soak it up! How Zinco green roofing made Berlin a “sponge city”

What is a “sponge city”? Berlin, Germany, has the answer with Charlie Living: a new residential complex with a special Zinco retention roof that’s designed to reduce the risk of urban flooding.

Charlie Living houses 289 apartments and seven townhouses. Designed by GRAFT architects and Man Made Land landscape architects, it’s an open, highly integrated modern neighborhood on the former Berlin Wall strip, near Checkpoint Charlie.

This resilient building is helping pioneer the sponge city vision, an urban design model where cities act as natural sponges, absorbing and filtering rainwater then reusing it efficiently.

An advanced Zinco green roofing system helped realize this vision, and backed by Environmental Product Declarations (EPDs), also enabled Charlie Living to achieve the U.S. Green Building Council’s coveted LEED Gold certification status.

Resilient, nature-positive and energy-efficient roofing 
 

While Charlie Living’s 4 000 m² roof ensures highly efficient water retention, it is also a “green jungle” that brings nature into the heart of Berlin and improves the building’s energy efficiency.

Through “evapotranspiration” and solar shading, Zinco green roofs create a natural cooling effect that keeps buildings cool in summer. In winter, the layers of roofing substrate and foliage act as efficient insulation – reducing energy costs and improving people’s quality of life.

How does Zinco’s unique water retention tech work? 
 

Using specialized Retentionspacer RS spacers, Zinco created a reservoir beneath the greenery, allowing the roof to store an additional 55 liters of water per square meter. Combined with a Zincolit Plus substrate, the system can hold up to 240 liters of rainwater per square meter.

In the face of a changing climate, this decentralized water management concept protects the nearby built environment from urban flooding by capturing and storing rainwater directly.

When extreme downpours exceed what the green roof and substrate can store, excess water is stored in the reservoir space. Precision flow limiters then control its release into Berlin’s municipal storm drainage system over 24-48 hours, preventing local flash flooding.

Using Zinco helped the developers of Charlie Living create an urban oasis in the heart of Berlin. Sustainable, resilient and energy-efficient housing that improves people’s life quality and blazes a trail for NextGen sponge cities across the world.