“Rainwater is a resource. Not waste.”

MetroPolder company creates multifunctional water storage on flat roofs in cities by smart watermanagement. The water storage is used to prevent flooding by heavy rainfall and used for irrigation and grey water systems.  Rainfall is changed from waste into a resource and unused roofs are changed into green roofs, roof gardens or solar parks. MetroPolder advises, designs and establishes water storage on flat roofs

Our philosophy:

Rainwater is a resource. Not waste.

Rainwater is often seen as waste. Rain is free and is the source of all life. By removing it through a gutter, we make it waste. This does not have to be the case. Rainwater is useful in the city. It cools, feeds plants, supplements groundwater, and can replace drinking water for many applications.  The most direct example being irrigating the roof garden above the polder roof system; no drinking water is needed and it provides greater biodiversity! A true Win win

Polder Roof®

The Polder Roof is the worlds first smart water storage on flat roofs.

With smart control of water, there is never waste. This is why all the rainwater that falls on the roof is collected and reused, or released without causing a burden to the system. The Polder Roof serves as the foundation for a green roof, rooftop garden or park. In addition, the water that is stored can be used for irrigation, infiltration or a greywater system.

Company Profile
Incorporation September 2017
Participation since September 2018
Founder Friso Klapwijk
Faculty Faculty of Civil Engineering and Geosciences
Employees Matthijs Monkelbaan, Cees-Anton van den Dool, Brian Schmitt, Merle van der Kroft, Olivier Hoes (TU Delft)


Company history and milestones
Daktuin Alphatoren, Leiden
2018 Dakvijver WTC, Den Haag
2018 Fieldlab Civiele Techniek, Delft
2018 Wibautstraat, Amsterdam
Groendak VvE’s Gravenloo, Spinozalaan, Voorburg
2017 Smartroof 2.0, Amsterdam
2017 Roof park Vivaldistraat, Amsterdam
2016 Roof park de Boel, Amsterdam
2014 Roof park/Roof garden B.Bylon, Amsterdam
2013 Polder Rood Zuidas, Amsterdam