Detached house Numada, Tokyo
Use of filter collector FS
Tokyo, Japan | 2005
Sumida is a district in the centre of Tokyo. There are still large residential quarters with single-family houses here. The Numada house was built in 2005 by architect Shinji Munakata in a gap of less than 50 m².
Rainwater harvesting is worthwhile in Sumida for 2 reasons: The district pays the equivalent of 400 € per m³ of storage volume. This means that the builder received about 45 % of the total costs of his rainwater system as a subsidy. The second reason is that the annual precipitation is 1,500 l/m².
With a filter efficiency of more than 90 % with the WISY filter collector, 36 m³ of drinking water can be replaced annually by rainwater, mainly for toilet flushing. The inlet to the cistern is designed in such a way that both a rainwater and a drinking water pipe lead into it. When the cistern is empty, the inlet can be switched with a toggle lever. At the vehicle parking area on the ground floor, a cleaning water tap is connected to the rainwater network. A removable valve top has been fitted here for safety. All pipes and tapping points are marked "rainwater" to avoid confusion.
WC and cleaning
Cistern volume [m³]
Roof area [m²]
Rainwater storage made of in-situ concrete under the building
Wisy products used
in the detached house Numada, Tokyo
To the project in Japan