Kima Yandell, who owns Katwall Inc., Seattle, a full-service metal stud framing and drywall contractor, is no stranger to green construction.
One of her most recent projects is Seattle’s Bullitt Center. The Bullitt Center, as you may already know, is on track to become arguably the world’s greenest and most sustainable office building.
It’s being built to the requirements of the Living Building Challenge 2.0, one of the most stringent of all environmental construction standards. That includes geo-thermal wells punched 400 feet deep to help with winter heating, and an expected 250-year life-span.
That’s compared to 40 years for traditional buildings.
Rain will supply the building’s water, with all waste-water treated onsite.
Its unique overhanging roof, that members of the design and construction team refer to as “the hat,” is a solar panel.
Plans are for the rooftop array to supply 100 percent of the building’s electricity.
Energy needs will be less than traditional buildings because Katwall crews installed a PROSOCO FastFlash air and waterproof barrier on the building’s Glassroc sheathing. Project architect Miller-Hull Partnership specified FastFlash for its ability to hold costly air leakage in and out of the building to better than Passive House levels.
They also chose FastFlash because it contains no ingredients on the Living Building Challenge’s Red List of hazardous materials found in many common construction products, such as phthalates, PVC, cadmium, lead, mercury and more.
Installation of the fluid-applied FastFlash system was easy and fairly routine, Kima said.
From lifts and hanging scaffolds, they sealed joints between the six-story building’s Glassroc panels with pink gun-and spread Joint & Seam Filler. They also used it on screw penetrations.
Red FastFlash, also a gun-and-spread sealant, sealed rough openings, fasteners and other penetrations to help maintain the integrity of the super-insulated Shuco curtain wall system.
They roller-applied tan Cat 5 primary air and waterproof barrier over the full expanse of the Glassroc sheathing. That creates a continuous, seamless yet vapor-permeable barrier to air and water. The system is a good choice for the damp Seattle climate since it’s instantly waterproof and can be applied to damp or dry surfaces.
Cat 5 takes its name from the fact that it’s been tested to withstand Category 5 hurricane conditions. Adhesion tests have shown that substrates fail before the FastFlash system will detach.
But it wasn’t just the products that had to be sustainable and environmentally friendly, Kima said. The plan that she and the rest of the construction team followed also specified sustainable and environmentally friendly construction practices.
“It’s no secret that there’s a lot of waste in construction,” she said. “How many job sites have you seen with huge piles of scrap lumber and other materials waiting to be thrown out?”
Katwall Inc has always tried its best to use materials efficiently, Kima said. On this project however, they took an extra-close look at their practices.
“We found that in the morning, before reaching for a new tube of Joint & Seam Filler, we could squeeze a little more out of the tube we were using at the end of the previous day,” Kima said.
“Or that bucket of Cat 5 that still had a few inches left? It might have a slight skin, but it’s still good under the dried skin.”
It didn’t take long, Kima said, for the habit of more rigorous conservation to take hold. Her crews found themselves engaging in these practices on other projects as well, even where they weren’t specified.
In the year since Katwall Inc began work on the Bullitt Center, Kima said the company has seen an unexpected but welcome 10 to 15 percent savings from the efficient — some might say “miserly” — use of materials.
It’s caught on in every area of her company, she said.
“We don’t make any real money from recycling soda cans or steel-stud scrap and cut-off ends,” Kima said. “We’ve just gotten in the habit.”
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