Eight stories above downtown Tacoma, a meadow needs a beehive.
Honeybees are working the dianthus, candytuft and evening primrose blooming in neon shades of pink, purple, and apricot high atop 1250 Pacific Ave.
The bees, and a modest population of ladybugs, are the unexpected residents of the 30,000 square feet of green roof that surely is the most colorful in the state.
If that 1130 Pacific address prompts an involuntary shiver, it’s probably because you remember your downtown Tacoma history. It was once the creepy parking garage next to the ill-fated people-mover, the blighted Escalade. Designed as a draw that would provide the parking to support vibrant downtown commerce, Park Plaza South instead sucked the life out of the streetscape. And that was before the moving sidewalk conked out.
PCS Structural Solutions, BLRB Architects and the City of Tacoma have collaborated on transforming the garage into the Pacific Plaza Building, with offices, retail space, parking, and the meadow that has been enchanting workers whose offices look down on it.
They’ve had a fascinating show as the plantings of sedum and succulents along the edge have spread, and the wildflowers at the center have phased in and out of season.
At times, the development of the roof has been a bit too fascinating, said Tom Bates, managing principal of BLRB Architects. Until recently, BLRB had its offices behind and up the hill from the Pacific Plaza Building. Its employees were challenging themselves to push the reborn building out of the silver, into the gold and toward the top platinum rating for energy and efficiency and ecological responsibility.
The team’s design preserved 78 percent of the original structure, said BLRB associate Ben Ferguson. Construction practices were rigorous enough to divert 97.9 percent of debris from the waste stream.
It was all interesting to watch, but the action on the roof was irresistible. The developers and their partners with the City of Tacoma nixed the old rooftop parking design, which sent gas and oil residue shooting through downspouts and flowing into the Thea Foss Waterway every time it rained. Instead, they built another three floors, and reinforced the top to accommodate a green roof.
There are energy advantages, Ferguson said. It insulates the building, and creates a microclimate that cools air around it in the summer.
It started with single-ply roofing, layered with a capillary fabric that absorbs and stores water. On top of that went a root barrier; two inches of crushed pumice for aeration; a filter fabric; a specially developed mix of Tagro soil, gravel, sand and clay; and, finally, a biodegradable erosion control mat.
“Solid waste has never before been used on a green roof,” Ferguson noted.
But then, Tacoma produces some of the finest solid waste on the planet.
The Tagro has fed the wildflowers and sedums chosen by Chris Cain of Valerian LLC through three seasons of brilliant color.
Without irrigation the roof would have gone brown in the summer, Ferguson said.
During planning, every time the subject of water came up, someone mentioned the Turkish baths, he said. Finally, a team of explorers from BLRB, PCS and the city found a manhole cover near the old people-mover, dropped through it and landed in perfectly preserved Turkish baths dating back to the 1880s. They were beneath the footprint of the Kentucky Building, whose proprietors had sold baths, whiskey and canoodling.
The Turkish baths are a water-tight cistern now, big enough to store 190,000 gallons of rain. That’s plenty to irrigate the meadow, flush all the building’s toilets and add a few more “eco-points” to its credentials.
No matter how dry the weather, Bates said, the drains on the roof are always returning at least a trickle to the Turkish baths. And the flowers are always blooming.
Bates, Ferguson and Josh Clarke, project manager for the city, see them as a living advertisement for working together to stretch expectations. They see them, and their bees, as a new standard of attainable loveliness.
Now all they need is a beekeeper with a hive to harvest that sweetness.
Kathleen Merryman: 253-597-8677
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