An architecture firm dedicated to green building felt the heat and got AC at the office. They still cut their energy use | KUOW

The content for this article was originally posted on KUOW on August 5, 2021.

“Watershed” is the name of the building Weber Thompson designed and now occupies in Fremont. In this photo, it’s visible on the left, under the Aurora Bridge. Credit: KUOW Photo / Joshua McNichols

During the deadly heatwave earlier this summer, we heard about people rushing to install air conditioning in their homes and workspaces here in Seattle. This made us wonder about a modern office building in the South Lake Union neighborhood designed to function without AC. Architecture firm Weber Thompson designed it to reduce their energy use.

Concerned about the changing climate, they designed their new office with air conditioning. KUOW’s Joshua McNichols told Paige Browning what he learned about their efforts to cool down efficiently.

This interview has been edited for clarity.

Paige Browning: First, how was the old building designed to stay cool without AC?

Joshua McNichols: It was based on a very old technique, but updated for today. In the days of the first skyscrapers, when you looked down at a building from above, many of them were shaped like letters of the alphabet, O’s and U’s and even E’s or W’s. The holes in those letters let light and air penetrate to the center of the building, so you can light them and get breezes blowing across them without electronics, without electric lighting, or air conditioning.

Weber Thompson turned to those old techniques. They built their office building in the shape of an O. Kristen Scott is a principal with the firm. She worked in that office:

“When it worked well, you feel like you’re outside under the shade of a big tree and there’s a breeze flowing.”

Kristen Scott in the new Watershed offices. Credit: KUOW Photo / Joshua McNichols

Did this work, even on excruciatingly hot days?

There is a point when it’s too hot outside for even a breeze to cool you down, because it becomes a hot breeze. When they designed the old building, they planned for some days like that. They had a casual dress code so that people could wear shorts if it was just warm in the office.

They estimated that the building would get so hot that they’d have to send everybody home maybe 20 hours a year, which seemed manageable at the time. But climate change has pushed the number of really hot days up. It crept up to 40 hours a year when it was too hot to work there. That’s a full week. And when nights are warm, the building can’t cool down at night like it was designed to. During heat waves, it would get into the 90s inside the office:

“When you realize that you’re sticking to the trace paper on your desk, that’s not a good thing,” Kristen Scott said.

90 degrees inside the office sounds very uncomfortable, but they were intent on lowering or cutting energy use. Did they just do away with that vision?

No, and this was the big surprise for me. The new building actually uses less energy than their old one did. Even though the new one has air conditioning, a heat pump. Technology made it possible. They’ve got high tech windows, tons of insulation, and more efficient air conditioning systems. Kristen Scott took me outside to show me the windows:

“So I’m standing outside here on Troll Avenue. We’re under the Aurora Bridge. If you look up here you’ll see the electrochromic glass that self-tints.”

When she talks about self-tinting glass, I’m wearing glasses like that right now. They turn dark when I step out into the sun. That technology alone dramatically reduced the amount of energy they need to cool the building. Also, they had to change their behavior. For example, they got rid of their server room where all their big computers were. They moved those servers to the cloud, because those computers put out a lot of heat, and when you put out heat you’ve got to cool it.

A lot of companies pledge that they’ll reduce their carbon footprint, and many fall short. What holds them accountable?

The occupants of this building monitor themselves to comply with the Living Building program’s requirements. The Living Building program is a voluntary program where designers and occupants of buildings agree to meet a super high standard for energy use and water use. The program requires them to monitor their performance.

Right when you enter the lobby of this building, in Weber Thompson’s office, there’s a big monitor that shows you how much energy the building is using in real time. If the occupants of this building fail to meet their goals, they’re on the hook through this program for a fine equal to five percent of construction costs, which are millions of dollars.

I’m glad they’re comfortable, but I kind of miss knowing that there could be a way to keep buildings cool without AC.

That’s right, and they do miss their old building a little bit:

“I’ll always have a special place in my heart for that building. It’s really a very comfortable thing to be in a space that doesn’t have any mechanical air movement. You are more connected to nature,” Kristen Scott said.

But, climate change has made nature more hostile, so being connected to nature becomes more difficult to manage.

Is the takeaway that there’s no way to keep an office cool during a heatwave with existing technology? Is it AC or bust?

I think that is one lesson you can take away from this. This company tried it — and it didn’t work. That suggests that, at least in offices, which put out a lot of heat because they have so many people and so many computers, yes, you have to have a way to cool them mechanically.

And are we expecting to see what this firm has developed in other buildings?

They’re going to try to roll out these ideas to more buildings that they do. Architects use their offices as advertisements of what can be done. It is a little tricky. Not everybody is going to want to spend their money to make their buildings this way. It is the direction that we’re going, though. Every few years governments ratchet up the standards that buildings have to meet. This architecture firm is a leader in that, and they’re influencing others.

Follow this link to Joshua’s previous report on Weber Thompson’s AC-free building.


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