The Chesapeake Bay watershed is home to 3,600 species of plant and animal life as well as 17 million people. The University of Maryland's WaterShed mimics and serves as a micro-ecosystem, an example to help manage the state's larger ecosytem. For the competition, Maryland even brought its own wetlands to the National Mall.
Water is the defining theme of WaterShed. As if perched on an alluvial island, the split-house butterfly form embraces yet is surrounded by constructed wetlands. The sense of water flow begins in the centerpiece courtyard rivulet, enticing visitors to enjoy the home. Trellises loaded with greenery, a green roof, lush gardens and burbling ponds both join and separate the living modules that distinguish private from public spaces.
WaterShed won the overall Decathlon V scoring 951.151 points (from a possible 1,000) . Among category wins was top honors in Architecture. It was a close second in the Market Appeal contest. However with the green roof, cistern and wetlands costs included, it scored 12th in the Affordability Category at $336,335.89.
WaterShed is made up of two modules connected by a bathroom module that deliver nearly 900 square feet of living space. Construction is " 'heavy-stick’ framing – triple 2”x6” studs, joists, and rafters spaced 4’ apart and is covered by 1-1/2” thick tongue-and-groove decking used as sheathing." The two larger modules have French door entries into the courtyard. The private module serves as both bedroom and office with a dedicated office nook, The bed folds closed into a daytime work table, The living module houses kitchen and living areas. The kitchen is adjacent to the vegetable and herb garden.
WaterShed's green roof slopes to feed runoff to the cistern and wetlands. The vegetation slows rainwater flow to the landscape while simultaneously insulating the living space below and improving energy efficiency. Collected grey water from the shower, lavatory, clothes washer and dishwasher also feeds through wetlands optimized for filtration and cleansing.
Humidity is an issue in Maryland. A patent pending liquid-dessicant waterfall serves as art and dehumifier; Maryland has displayed several versions of this feature in past decathlons. A high-saline liquid solution absorbs humidity from the air; heat from the solar panels dries the dessicant for re-use. This year LED lights illuminate the waterfalls.
But it is that most private of spaces, the bathroom, that is the centerpiece of WaterShed connecting the two larger modules but also showcasing the mini-ecosystem. The shower has a large window screened with vegetation outside. Though private, one using the shower feels as if one is showering outdoors.
A 9.2 kW photovoltaic array powers the home; it is clipped to the standing seam metal roof and features micro-converters. A dedicated evacuated-tube solar-thermal system heats water. WaterShed was among the seven entries that succeeded as a net-zero home.
For more coverage of Solar Decathlon V, click here.