The Bullitt Center in Seattle has been called the world's greenest commercial building. That's a bold claim, and one that I had to check out during a visit to Seattle for the Passive House Northwest Conference. It was built as the home of the Bullitt Foundation, a group whose mission is "to safeguard the natural environment by promoting responsible human activities and sustainable communities in the Pacific Northwest." The building itself is a demonstration project, showing what's possible today using building products and components available to anyone. And what a project it is.

solar hat on Bullitt Center

All the terrible photos are by Lloyd Alter unless otherwise noted and properly exposed

The most prominent feature of the building is its big steel hat of solar panels; the building is designed to produce more electricity than it needs. That's one of the requirements of the Living Building Challenge, perhaps the world's toughest green building standard. According to their original calculations, they needed more area of solar panels than could fit on the roof, so they got permission to hang out over the sidewalks. In fact, they have found after occupying the building that they are generating way more electricity than they needed, and the hat could have fit on the building.

bullitt staircase

In most buildings, the stairs are buried in the interior. At the Bullitt, "active design" is part of the program, with this "irresistible stair" at the entrance of the building, designed to encourage its use. They claim that "This stairway has near-magical powers: people can’t seem to resist going up." It is a beautiful stair, all crafted of wood and steel and enclosed in glass, but I found it a bit scary near the top, seeing all the way across Seattle to the mountains.

coworking space in Bullitt Center

The office floors are warm and comfortable, with very high windows to let natural light penetrate deep into the building. The structure is built with a glulam (glue-laminated wood) frame, with wood decking (2x6s on edge) above. This is how they have built warehouses in Seattle for 150 years, albeit with solid rather than laminated wood; it is strong, durable and deals well with earthquake forces. Everything is high quality, as the building is designed to last for 250 years.  

All the furniture is selected for compliance with a "red list" of prohibited chemicals specified by the Living Building Challenge. This is really hard to do; a lot of companies use proprietary and "trade secret" ingredients and materials. Other items, like PVC, are so commonly used that it's hard to find building products without them. 

drain pipe in Bullitt Center

Here is an example: the joint on a drain pipe is usually made of neoprene, a foamed plastic that is on the "red list." You can get alternatives, like the blue sleeve seen here, but they are hard to find and a lot more expensive. 

stainless steel exterior shades on Bullitt Center

Having such big windows can be a problem when the sun is shining, particularly in summer, so they have stainless steel exterior shades, that can be adjusted to cut solar gain or bounce and scatter light, preventing glare.

top floor of Bullitt Center let the light shine in

On the top floor, in the space recently vacated by an engineer who took over a whole lower floor, the windows are particularly dramatic. All the wood, glass and concrete floor work together to make this some of the most attractive office space I have ever been in; Architects Miller Hull did a terrific job here.

ground source heat pumps at Bullitt Center

The building is heated and cooled with ground source heat pumps; there are 26 loops drilled down 400 feet. This is about twice as many as needed, but they designed in extras in case any were damaged in the inevitable earthquake. Being under the building, they cannot be fixed or redrilled, so it is a sensible precaution. The pumps run on electricity from the solar panels. 

water system

Some of the Living Building Challenge requirements are so tough that they are not even legal. For instance, all water used is supposed to be captured on site from rainwater. There is a huge 56,000-gallon cistern to catch it all. However it is illegal in Seattle to do this on a commercial basis, turning the building into a private water works. There is also a requirement that all water be chlorinated to kill bacteria, but chlorine is on the red list, so they have to take it out again with activated charcoal. 

This system is not yet approved, so right now the building is using city water for drinking. It's one of the few areas where I think the Living Building Challenge is wrong. Water is a public service, carefully monitored and cleaner than bottled water. If you're part of a larger community with a safe municipal water supply, you should use it. There are some things that we do better together. 

composters at Bullitt Center

Regular toilets use a lot of water. Because the Living Building Challenge requires all water to be processed on site, composting toilets are used instead. The toilets are waterless foam flush that are actually nicer than regular toilets; there is no smell because fans suck air down the plumbing and exhaust it to the roof. The solids are removed from those drawers once a year or so and mixed with sawdust and turned into fertilizer; the little bit of liquid leachate is pumped out and taken to a liquid waste facility and is somehow " used in a bird sanctuary".

bike parking only

The only parking in the building is for bikes. These are going to be seriously fit people; I walked there and it was uphill all the way. Brad Kahn, who conducted my tour, commutes seven miles each way on this electric-assisted bike. I usually think these are for wimps but not in this town; I would get one here for sure.

Bullitt Center exterior

Is the Bullitt Center really the world's greenest commercial building? I used to put my money on another building in Norway, but I'm going to have to take that back. The Bullitt goes at everything — from water to electricity to materials, it does it all. It's perhaps a bit expensive to be replicated everywhere, but it certainly is a model of where we should be going. I think they've nailed it.

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Lloyd Alter ( @lloydalter ) writes about smart (and dumb) tech with a side of design and a dash of boomer angst.

Bullitt Center: World's greenest commercial building?
A tour of the Bullitt Center in Seattle confirms that it's as green as it can be.