Green Design: New House Raises Tilapia, Monitors Water Use

A university team competing in the recent Department of Energy's Solar Decathlon competition has built a house that runs on rainwater and sunshine. What, no love? Called NexusHaus, it was on display at the recent competition in Irvine, Calif., according to an article in Builder Online.

The team, University of Texas at Austin and Germany's Technische Universitat Munchen, wanted water conservation to be a central part of the house design, because the drought in Central Texas could before long reach the same urgency as California's, particularly because of Texas' population boom, as the article noted.

The 70-plus design students on the project aimed for the house residents to use 25 gallons of water per person a day--this compares with a traditional home's use of about 100 gallons per person a day. Their ways to reduce water use included using a Bloomberg dishwasher, which uses 4 gallons of water for each cycle, and an Equator clothes washer, which uses 9.5 gallons, said the article.

In the house, water from the shower, bathroom sink and clothes washer is filtered and used again in a drip irrigation system, which allows up to 75 gallons of graywater a day for landscaping. Condensate from the HVAC system will be used to add a bit of water to the aguaponic grow beds. The latter will contain vegetable gardens and fish that can be eaten, such as tilapia. The system between the plant beds and fish tank is kept clean by harmless bacteria, as the article noted.

Rainwater capture will provide all potable water needs, but the house would be connected to a municipal water supply to provide backup during spells without rain. A 2000-foot canopy between two parts of the house will gather rain, which then circulates through gutters into bladder tanks below the decks. The tanks can hold 5,000 gallons. The water then goes through a two-part filtration system: carbon filtering and UV light filtering in order to reach the national standard for drinkable water, noted the article.

Because seeing a monthly line-up of one's own water use helps fight water waste, the NexusHaus team provided a technological monitoring system that provides minute-by-minute information on water usage amounts. From the same system, homeowners can also look at indoor temperature, control humidity, and energy usage, said the article.

The team's house design is intended to be re-used, particularly to provide infill -- extra lodgings or buildings on property lots that already hold other structures -- for Austin's "alley flat initiative," which aims to provide affordable extra dwellings in backyards of the city, the article confirmed.

For more great nature science stories and general news, please visit our sister site, Headlines and Global News (HNGN).

-Follow Catherine on Twitter @TreesWhales