The designers of Seattle’s Bullitt Center set out to prove that a six-story office building could generate all its own energy. And, after one year of operation, they have surpassed this ambitious goal: the 52,000-square-foot building is sending a sizable surplus to the grid. The architects Miller Hull Partnership integrated a suite of energy-saving strategies, including passive climate controls, radiant floors and 14-foot floor-to-floor heights with correspondingly tall triple-glazed windows.
Factoring in the excess energy generated by the 242kW solar array on the cantilevered roof, the site’s net energy-use intensity (EUI) is an amazing -6kBtu/sf. The building also captures rain and treat it to achieve potable standards. These energy numbers demonstrate that net zero office buildings are viable even in overcast Seattle, at least at six stories.