Every time it rains, this concrete house turns into an oversized water filter.

Rainwater runs from the roof through a custom-designed system and ends up in a cistern, clean enough to drink.

A demonstration building was on display during Milan Design Week last month, complete with a fake cloud overhead to show it in action.

Using rainwater to supply drinking water could be “the missing link for ecological housing,” says Katalin Ivanka, creative director for Ivanka.

While it’s becoming more common for buildings to capture rain to water plants or flush toilets, even the greenest buildings still tend to use water from the tap for drinking and cooking.

In cities, where rain rushing down streets can lead to flooding and overflowing sewers, new rain-harvesting buildings could serve as an alternative form of stormwater management.

In countries that get plenty of rain but lack safe drinking water, the buildings could act as water treatment plants. T

he company also envisions the system scaled up for use in “rainwater factories” to supply pure water for manufacturers.

Here’s how it works: When the first drops of rain fall, the water is directed into a separate tank, so dirt and contaminants from the roof won’t go into the system. x

Eventually, the rain is redirected through a series of filters, starting with a patented material called “bioconcrete” on the roof.

Specially-designed stainless steel pipes filter out more contaminants before the water lands in a cistern.

“The bioconcrete cistern has a key role in the process,” explains Ivanka. “It acts like a natural limestone cave formation, and orients and sets the pH to the ideal range. It further softens the otherwise naturally soft rainwater.”

A silver surface on the tank keeps it clean, and a final set of filters (carbon, UV, reverse osmosis, and a few more) take care of the last step of purification.

No chemicals are used.

The technology can be added on to an existing roof, or incorporated into new designs. The company estimates that it could be used in about half of the world's countries.

2014-05-09

Co.Exist

This House's "Bioconcrete" Turns Every Drop Of Rain Into Drinking Water

If your entire house is a water filter, clean water is never hard to find.

Every time it rains, this concrete house turns into an oversized water filter.

Rainwater runs from the roof through a custom-designed system and ends up in a cistern, clean enough to drink. A demonstration building was on display during Milan Design Week last month, complete with a fake cloud overhead to show it in action.

Using rainwater to supply drinking water could be “the missing link for ecological housing,” says Katalin Ivanka, creative director for Ivanka, the Hungarian company that designed the Rainhouse system. While it’s becoming more common for buildings to capture rain to water plants or flush toilets, even the greenest buildings still tend to use water from the tap for drinking and cooking.

In cities, where rain rushing down streets can lead to flooding and overflowing sewers, new rain-harvesting buildings could serve as an alternative form of stormwater management. In countries that get plenty of rain but lack safe drinking water, the buildings could act as water treatment plants. The company also envisions the system scaled up for use in “rainwater factories” to supply pure water for manufacturers.

Here’s how it works: Falling rain is redirected through a series of filters, starting with a patented material called “bioconcrete” on the roof. Specially designed stainless steel pipes filter out more contaminants before the water lands in a cistern.

“The bioconcrete cistern has a key role in the process,” explains Ivanka. “It acts like a natural limestone cave formation, and orients and sets the pH to the ideal range. It further softens the otherwise naturally soft rainwater.” A silver surface on the tank keeps it clean, and a final set of filters take care of the last step of purification. No chemicals are used.

The technology can be added on to an existing roof or incorporated into new designs. It can also be customized for any size of building, from a single-family home to a plant that manufactures food. Of course, it doesn't work everywhere--if a city doesn't get adequate rain, the building won't be able to harvest it. The company estimates that it could be used in about half of the world's countries.

"Less and less freshwater is available on Earth, but we need more and more of it," says Ivanka. "Unlike oil, it can't be replaced by other materials." The company plans to license the technology everywhere, and to make part of the technology available open source.

Despite the company's environmentally minded motivations, though, they have at least one blind spot: They're planning to start using the buildings to make bottled water.

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3 Comments

  • Kinga Antoniu

    To make bottled water from this source is missing the point. Plastic bottles are taking over the planet. If this can be implemented perhaps drinking fountains can be added to the exterior of buildings for drinking, omitting the need to for "bottled water". Is this company looking to make an environmental change with producing bottled water?

  • My first objection to the write-up above is the claim that "no chemicals are used". To truly evaluate this product one would need to know the chemistry of the concrete involved, how it interacts with rainwater, and its potential for supporting microbial growth, all as seen over time.

    The following quote from the link found by clicking "Rainhouse" above is not encouraging that the science here is well understood:

    "The technology’s testing is taking place in the location of IVANKA’s owners at Balaton Uplands National Park where geographic parameters are the most suitable for the project in Central-Europe. Lake Balaton is the largest freshwater-surface of Europe so the air is especially pure and rainfalls are favorably frequent in that region."

    Many people in the world already use rooftop cisterns. If they are lucky, they live in an area where the rainwater is fairly clean and they use the water before microbial problems have time to develop. Where is the before and after data here?

  • Tom Piper

    I installed a rain harvesting system for my home from a company in Australia. I added a non-chemical filtration system for the drinking water, which I have tested regularly.

    I'm no expert on this system but they mention using a silver surface on the tank. Silver has been known as an anti-bacterial for centuries. Hospitals are starting to use silver embedded equipment and bandages to combat the deadly staph germ MRSA.

    Essentially when bacteria comes in contact with silver it inhibits the chemical bonds at the cellular level which are required for its survival. Basically it falls apart.