LEED? Lame. Passive House? That's past time. Built Green 4-Star? Boring. Want to be like the cool eco-friendly kids? Well then you better move into a Built Green Emerald Star home. Right now, there's only one of them in Seattle and you just missed your chance. Dwell Development sold the 2,218-square-foot Ballard house at 1749 N.W. 61st Street on Monday for $850,000. What makes a home Built Green Emerald Star? There's a whole checklist of energy-efficient and eco-friendly things that go into it. The key is to be Zero Energy Ready and Dwell got there with the help of a 6.6-kilowatt solar array, air-to-water heat pump, high-performance windows, Enviro-Dri weather-resistant exterior barrier system, Zehnder heat recovery ventilation system, low-flush toilets and much more. Caron Architecture designed the home, which is covered inside and out in reclaimed wood and steel from Oregon, Montana and elsewhere. Dwell also built two 5-Star townhomes right behind the Emerald Star but both of them have apparently been sold as well. As for the Emerald Star, the new buyers are a couple moving to Seattle to work for Amazon. Of course they are.