Chicago's mayor, Richard M. Daley, has a goal: to make it the most environmentally friendly city in the United States. The city is already well-known for its efforts and achievements in greening the urban landscape and buildings, but it will take the participation of all Chicago's citizens for the city to truly achieve super-green status. One homeowner took the mayor's goal as a personal challenge and set out to prove to the community that green homes can be as beautiful and comfortable as they are energy efficient and sustainable—and that they are as viable in the Midwest's variable climate as they are in the perpetually sunny Southwest.
Michael Yannell, a pharmacist at Rush University, called on local sustainable architecture firm Farr Associates to design a showcase of net-zero energy and sustainability. The result is a very modern and attractive package: a house that produces more energy than it uses, incorporates highly energy efficient systems, integrates multiple renewable energy and water-conservation systems, and paves the way for future residential use of graywater reclamation systems. At the time of its completion in May 2009, the Yannell Residence had also achieved the highest LEED for Homes Platinum rating to date, earning 115.5 points. (The highest residential LEED Platinum rating to date is 121.)
"The idea was to take the same amount of money—or less—than would typically be put into an average custom home in Chicago, and make it smaller, more elegant, and very sustainable," says Jonathan Boyer, AIA, principal and director of architecture at Farr Associates and the residence's chief designer.
High-end residential construction starts around $350 per square foot in Chicago, and the Yannell Residence cost about $400 per square foot to build, according to Jeff Berry, partner at Goldberg General Contracting, the house's builder.
At 2,675 square feet and with a total cost of $1.6 million, the house is smaller and costs a bit less than a typical high-end home in the city, in keeping with Yannell's intent to demonstrate that there is a green alternative to oversized, multimillion-dollar custom homes. Its two wings, connected by a foyer, separate the kitchen, dining, and living areas from the bedrooms, office, and music room, and also provide enough area to support 48 photovoltaic panels on twin butterfly roofs. The exterior is finished with a combination cedar and fiber-cement rainscreen cladding. Floor-to-ceiling walls of triple-paned windows along both wings' southern exposures bathe the open interiors with light, creating a warm, bright environment. Yannell and the design team were restrained in their selection of interior finishes and materials, eschewing extravagance and using all recycled-content materials, as well as low-VOC finishes. Interiors are clean and modern, but welcoming.
The house definitely stands apart from others in its neighborhood, but that was the intention. "It is not a background building. We wanted to make a statement, because we think there aren't enough people who realize that a zero energy home isn't the home of the future—it is possible now," says April Hughes, Farr's project manager for the Yannell Residence.
To achieve performance and sustainabilty goals, Boyer oriented the house on its lot for passive solar, then incorporated a 10kW photovoltaic system, a solar hydronic system, and a geothermal heat pump. A plenum wall taps into the HVAC system and redistributes heated air. The photovoltaic panels are mounted atop the house's two butterfly roofs; and reflected light from the roof's surface boosts energy production. As of September 2009, five months after completion, the house had produced about 7,500 kWh of electricity—well over its design estimates. A web-enabled data logger embedded in the photovoltaic inverters tracks the house's energy production.
Despite the city's location near a seemingly abundant water source—the Great Lakes—water conservation is critical, and Yannell wanted his house to be as water-efficient as it is energy-efficient. Not only does the house use rainwater funneled from the butterfly roof to feed the landscape irrigation system, it also boasts the first residential graywater reuse system in the city. As with the rest of the house's systems and technologies, the purpose of using a graywater system wasn't to save money or earn a return on investment, but to demonstrate that graywater systems are a viable solution for residential water conservation. The plan was to reclaim waste water from the washing machine to flush the home's two toilets.
However, Chicago's residential building code doesn't allow a secondary water source or a nonpotable water source to be used for this purpose, so getting the graywater system approved by the city's regulatory committee was a challenge. The design team had to show that its solution would meet standards for potable water sources, and in doing so, it created a regulatory path that will make it easier for builders and designers to implement residential graywater systems in the future, according to Boyer.
To explore the Yannell Residence more fully, visit the owner's website. Tours for interested parties may be scheduled through the website, as well.
For more on graywater harvesting, click here.
Further reading on LEED-H, solar, net-zero energy, and passive design:
2009 Solar Decathlon Coverage
Record-Breaking LEED Home in Oregon
Massachusetts Zero Energy Challenge and the competition winners
Minding Your Meter
Net-Zero Living is Light on Sacrifice
High-Design, Low-Impact House Wins Multiple Awards
University of Nebraska Students Build Net-Zero Energy HousePassive House Design in Philadelphia