Swinerton Builders announced last week that it has achieved LEED Gold on its modernization of the Gates-Thomas Laboratory at Caltech college in Pasadena, CA. This is the first project in California and the first higher education facility in the United States to earn LEED Gold under BD+C v4, says the company.

Under the U.S. Green Building Council’s new robust LEED v4 program, projects must meet a much more complex grading criteria before being determined LEED certified. BD+C stands for Building Design and Construction and it applies to new construction and major renovation.

David Cramp, Swinerton project manager for the job, says with BD+C v4 there is a "lot more emphasis on cradle-to-grave type analysis of materials and equipment. He says materials require certifications "going back to raw materials, source, locations, etc."

Cramp told me that BD+C v4 can be challenging because the industry hasn’t fully adopted to the standards and there are not a lot of material options that meet the certification requirements.

On the Caltech project he says the most interesting and challenging aspect was the major structural addition of a three-story stair case and pop-out auditorium with roof top deck. "This required demolition of 12” thick walls, major steel reinforcement, excavation in a tight location, and installation of new curtain wall," he says.

"We overcame the challenges by working closely with the design teams and Caltech to develop plans, logistics, and sequencing that worked the best for all parties," says Cramp. "There were occupied building all around and we planned and communicated our activities three weeks in advance and [had] weekly team discussions and daily client discussions."

Home to the Department of Mechanical and Civil Engineering, the 70-year-old Gates-Thomas Laboratory is listed as a historic building in Caltech’s master plan with the city of Pasadena. With three stories above-grade and two below-grade, Swinerton partnered with architect AC Martin to fully modernize the 54,000-sq-ft interior. The nearly $17 million project began construction in April 2014 and completed in May 2015

As part of the retrofit, the roof was redone to allow for new rooftop mechanical equipment. The historic doors, windows, and façade were also retrofitted, while the exterior hardscape was redone with new retaining walls, rails, and landscaping, and existing concrete walls, beams, and columns were reinforced. Swinerton self-performed extensive concrete work, including all the new concrete site retaining walls, slab-on-grade, slab-on-metal deck, and the three-story stairwell.

To help meet LEED Gold, many sustainable features were added, including LED lighting, natural daylighting, smart occupancy controls, high-efficiency fixtures, and low-flow toilets. In outside public spaces, Swinerton installed a drip-irrigation system, along with landscaping featuring native vegetation and drought-tolerant species adapted to the local climate.