It’s alive! Inside the world’s greenest building

The Bullitt Foundation, whose mission is to safeguard the environment, spent $18.5 million to construct this uniquely sustainable office building.

The Bullitt Foundation officially opened its Bullitt Center on April 22, 2013. The building meets the standards of the Living Building Challenge, a series of ambitious performance requirements including net zero energy, waste and water. To get there the building has a large solar panel array on its roof, a system for gathering and treating rainwater and a design that minimizes electricity use. John Stamets
An array of 575 solar panels covers the roof, which slopes 5 degrees southwest. At 425 watts per panel, the array's peak output is about 250kW. This panorama is stitched from several images. John Brecher / NBC News
Exterior shades surround the building's windows, extending and retracting based on weather. They counteract glare by bouncing light up toward the ceiling on sunny days, and also reduce unwanted solar gain. John Brecher / NBC News
The building controls its temperature partly through the use of large, operable windows. Instead of swinging on a hinge, they push out laterally four inches to avoid interfering with the exterior window shades. John Brecher
The "irresistible staircase" in the Bullitt Center is intended to lure people away from the elevator. Designers used low risers, bright window light and a prominent location near the entrance to encourage use of the stairs. John Brecher / NBC News
Some of the building's structural wood-laminate posts are visible on the fourth floor. Designers chose wood as a sustainable material since it's abundantly available in the Pacific Northwest. John Brecher / NBC News
A sign advising not to drink the building's reclaimed water sits above a composting toilet. Water captured from the roof and treated in the building's purification system will initially be used only for flushing toilets before it's approved for other purposes, such as sinks and showers. John Brecher / NBC News
The lowest floor in the building houses its water treatment and waste composting systems. Here, filters for water purification sit next to a holding tank. This image was stitched from several frames. John Brecher / NBC News
Rainwater from the roof will flow to a 56,000-gallon cistern in the basement, shown here in the early stages of construction, while sewage will be treated in 10 composters.

Water from showers and sinks will be filtered on a “green roof” above the ground floor and then filtered through planted swales. John Stamets
The Bullitt Center will circulate fluid through 26 geothermal wells to heat the building. Seeking to gain every available degree of efficiency, workers wrap insulation around piping for the system in December 2011.

Electricity for the building will come from solar panels that extend over the sides of the roof. John Brecher / NBC News
Wood for the project is either recycled or sourced from areas where forests are sustainably managed. John Stamets
Denis Hayes, 67, left, and Jason McLennan, 38, are from different generations, but they share a passion for reducing the impact buildings, and humans, have on the environment.

Hayes, who co-founded Earth Day with Gaylord Nelson, now heads the Seattle-based Bullitt Foundation. McLennan, an architect, is CEO of the International Living Future Institute.

Inspired by the institute's Living Building Challenge, the foundation is building a new Seattle headquarters that should produce more energy than it uses.

The challenge aims to certify green buildings around seven performance areas: site, water, energy, health, materials, equity and beauty. The images on the following slides illustrate how the Bullitt Foundation aims to meet those goals. John Brecher / NBC News
This view from atop a crane at the Bullitt construction site shows the neighborhood, with Seattle's skyline in the distance.

A key tenet under equity is that a Living Building must foster a sense of community -- and plans are to create a learning center on the ground floor to invite community participation. John Stamets