ECO-STRUCTURE recently caught up with Amy Gardner, AIA, and Brian Grieb, AIA, faculty advisors for WaterShed, the University of Maryland house that won the U.S. Department of Energy’s 2011 Solar Decathlon.
How is your solar paneling unique?
Our 9.2kW photovoltaic array consists of 42 solar panels, 36 of which are mounted to the roof of the north module, eliminating the need for roof penetrations. The remaining six are mounted to the pergola structure, creating a canopy that shades the west side of the north module. DC-to-AC electrical conversion occurs under each panel using micro inverters. This allows each panel to be monitored independently while optimizing the overall performance of the system.
What other sustainable features have you incorporated into your design?
WaterShed’s holistic design responds to the challenges of rethinking energy use in the built environment and concerns about water consumption around the world. Inspired by the Chesapeake Bay, WaterShed’s architectural design is driven by four guiding principles:
1. Water is a precious resource and should be handled conscientiously
2. A home should function as a micro-ecosystem
3. A sustainable house should both conserve and produce resources
4. Merging the best of passive and active energy strategies is the most effective way to create a house in tune with its environment.
To achieve these goals, some our sustainable features include the following:
1. Constructed wetlands filtering storm water and graywater for reuse
2. A green roof retaining storm water and minimizing the heat island effect
3. an optimally sized photovoltaic array harvesting enough energy from the sun to power WaterShed year-round
4. Edible landscapes supporting community-based agriculture
5. A liquid desiccant waterfall providing high-efficiency humidity control in the form of an indoor water feature
6. A solar thermal array supplying enough energy to provide all domestic hot water, desiccant regeneration, and supplemental space heating
7. Engineering systems working in harmony and each acting to increase the effectiveness of the others,
8. A time-tested structural system that is efficient, cost-effective, and durable
What was the inspiration of your design, and does it display any regional influences?
Our inspiration comes from the Chesapeake Bay and its watershed. Covering 64,000 square miles across six states and the District of Columbia, the Chesapeake Bay watershed is the largest estuary in the United States. It includes over 100,000 smaller rivers and streams that eventually drain into the Bay. With over 16.6 million human inhabitants of the Chesapeake Bay sharing the watershed with nearly 4,000 species of plants, fish, and animals, the subtle ecological balance is increasingly threatened by the development of our cities, towns, and neighborhoods. To minimize the impact and bring harmony between these natural and manmade systems, WaterShed’s design serves as a model for how our built environment can help preserve the richness of watersheds everywhere by managing stormwater on site, filtering pollutants from graywater, and minimizing water usage.
The house is formed by two rectangular modules capped by shed roofs, sloping towards each other, and is therefore well-suited to capturing and using sunlight and rainwater. A home that harvests, recycles, and reuses water, WaterShed not only conserves but produces resources with the water it captures. Inspired by the rich, complex ecosystems of the watershed, the home displays a harmony between modernity, tradition, and simple building strategies--doing so with cutting-edge technological solutions to achieve high-efficiency performance in an affordable manner.
How has the new affordability criteria affected the design of your house?
The new affordability contest was a huge help to our team’s design process. It provided checks and balances to the design decisions and forced us to be more strategic. These led us to essentially an approach that was guided equally by the following: careful use of project documents, such as our drawings and project manual, to build a budget and closely track costs along the way. We designed a modular home that is composed of three main components and a few subcomponents. With the rough framing of the three main components prefabricated in a factory, we were able to maximize material efficiency and reduce waste. In short, we used ordinary materials in extraordinary ways.
What will happen to the house after the Solar Decathlon?
The university is working on possibilities for WaterShed’s final home. Wherever it ends up, we hope it continues to show that implementing green technology and design can be easy, affordable, comfortable, and beautiful, and that sustainable building is truly design within reach for everyone.