No AC? No problem for this new office space

A new office building, which is claimed to be Seattle's first in many years without air conditioning, makes a modest boast. It promises a maximum of 20 hours a year with interior temperatures higher than 85 degrees.

That's a lot of heat for Seattleites, no matter how ecologically devout.

But the designers and primary tenants of the innovative four-story building, at 225 Terry Ave. N. in South Lake Union, view their headquarters as a bold experiment.

"It's going to be a tough sell for naturally ventilated buildings, but that's why we did this -- we wanted to show it will work," said Scott Thompson, a senior principal at architecture and design firm Weber Thompson.

"Shorts and flip-flops!" exclaimed Peter Greaves, a principal at the 90-person firm, which specializes in residential design.

"This is going to be a lot like living at home," agreed Thompson. "It does require user participation, but our group is into that. It's a living, breathing building."

When the firm outgrew its space in the neighborhood after 17 years, it spent more than three years designing a 40,000- square-foot building.

Architects and designers highly value the quality of their own surroundings, and Weber Thompson's employees said in a poll that their biggest priorities are natural daylight and natural ventilation. Noise, some heat, bugs through unscreened windows -- those they agreed to live with.

Last week the firm moved into its $10.2 million home, meant to be a model for the best sustainable practices not just in air conditioning but also in heating, using recycled building materials and conserving water and power.

On the year's warmest day so far (Saturday hit the low 80s), workers were fine, even with the windows closed, Greaves reported. A blog will chronicle workers' experiences, and the principals said they plan to carefully monitor the system, comparing it with the conventional early-1980s building they just vacated.

The design will save 30 percent annually in operating expenses over such a building, Thompson said. Since the firm pays those expenses, the savings go right into its own pocket.

With its open sightlines, clean design and practice-what-you-preach philosophy, the building also will help attract and retain personnel, increase productivity and cut employee illness, Thompson predicted. The firm occupies all but the top floor and part of the ground level.

Ideally, the building will earn gold LEED certification for its core and shell, and platinum certification for its tenant improvements, Thompson said.

Certification of LEED (Leadership in Energy and Environmental Design) by the U.S. Green Building Council is a mark of prestige among architects that's also increasingly valued by clients, Thompson said.

Even a quick glimpse of the building reveals its unusual cooling system. In fact, that system's only conventional aspect is a ceiling fan in the conference room. Heat is provided by conventional radiators hooked to a gas-fired boiler.

		Paul Joseph Brown / P-I
	The exterior of the Terry Thomas building features tinted glass shades that mitigate heat gain on the windows.

More is happening in the building that's less obvious. The fluorescent lights throughout are brightened or dimmed by natural-daylight sensors at the windows, to minimize power consumption. Walls are mostly white, to reflect as much light as possible. Exposed beams feature drilled-out holes to save structural weight. Only one elevator serves the building, to encourage the use of stairs.

Restrooms feature motion-sensitive light switches, metering water and soap dispensers, waterless urinals and water-saving toilets. They could reduce water usage by up to 30 percent, said project manager Elzbieta Zielinska.

But it's the lack of AC that really makes the building notable. Centralized air, first used in a large U.S. office building in about 1931, led to hermetically sealed buildings in the late 1940s -- a lasting American tradition, said University of Washington architecture professor Jeffrey Ochsner.

He noted that Weber Thompson's design doesn't lend itself to high-rises with solid cores, or to buildings that lack the open seating plans possible when tenants occupy entire floors. Still, he deemed it intriguing.

"There are a lot of people in Seattle who are ecologically conscientious, and AC means space and expense," he said. "What you're more likely to see is new office buildings with opening windows and limited AC, for those few days when it really is needed."