Rainwater harvesting bowls designed by Iranian architects

Giant rooftop bowls to collect rain and so provide sustainable water supplies have been created by Iran-based BMDesign Studios.

The Tehran company drew up the concept when planning a primary school in the city of Jiroft in Kerman province – but it emphasises the technology could be adapted to any structure, especially those in areas with similarly parched climates.

“Approximately 85% of Iran has an arid, semi-arid or hyper-arid environment,” said the architects.

“Unfortunately, every year, this zone expands. Big lakes like Lake Urmia have shrunk to a fraction of their size, gradually disappearing.

“The consequences include thousands of farmers losing their jobs and [pushing] the city itself to the brink of rationing drinking water. We may not be very far from witnessing a big displacement of people.”

The idea came about when the architects devised a way to offset the school building’s water consumption.

They came up with a double-layered roof featuring undulations and huge bowls designed to collect rainwater. The studio estimates its Concave Roof system could help the school collect up to 28 cubic metres of rainwater.

“The outer shell provides additional shade for the domed roof while letting the air freely move and cool both roofs off,” explained the architects.

“The inner shell itself is slightly domed as only a section of a domed roof receives solar radiation directly at any time.

“A concave roof like this will help make even the smallest quantities of rain flow off the roof and eventually coalesce into bigger drops just right for harvesting before they evaporate.”

The school’s design also features rainwater harvesting reservoirs between walls that would help to cool the building and in turn reduce the need for air conditioning. Recessed windows and doors, and a sunken courtyard would also help control heat build up in the classrooms, offices and library.

Date palms planted around the building would contribute further shade, as well as a source of food.