Built Green White Paper – February 2018
Emerald Star is Built Green’s highest certification level. To date, only four projects have achieved this status. Dwell Development’s Ballard Emerald Star Home, certified in 2015, was the third project to receive Emerald Star certification and the first to do so in the city of Seattle. Emerald Star certification requires that a project demonstrate it will achieve net zero energy use and a 70% reduction in average water consumption through modeled projections. Given that modeled projections may differ from reality, however, it is important to compare models to actual performance once a home has been lived in. In 2017, Built Green undertook this comparison for the Ballard Emerald Star and analyzed the home’s energy and water consumption to determine whether the modeled projections accurately predicted real-world outcomes. The results showed that this project well exceeded net zero energy use, producing 3,941 kWh more renewable energy than energy consumed over a 25-month period. The residents also used just 19.95 gallons of utility-supplied water per person per day, slightly less than the required 20.1 gallons per person per day (a 70% reduction from the average 67 gallons per person per day Emerald Star baseline).
In addition to the environmental impact, meeting these energy and water reduction goals contributes to significant financial savings. As a result of selling electricity to the local utility and receiving a renewable energy credit, the Ballard Emerald Star owners have earned $3,533 thus far! They also save an estimated $493 in water and sewer bills annually. These financial savings contribute greatly to the homeowners’ expressed happiness with their home, though they also cite the home’s comfort and design as factors.
It is clear the Ballard Emerald Star is realizing its environmental goals through both quantitative and qualitative measures. After two years of being occupied, the home is exceeding net zero energy performance and has cut utility water consumption by more than 70% compared to the average household. The home demonstrates that the Emerald Star certification parameters are achieving the desired results and that deep green buildings such as this can be successful in a speculative housing market, leading to happy homeowners.