Designers have torn through massive amounts of information to construct a San Francisco hospital– before the foundation is laid.
Atul Khanzode is a building contractor navigating his way through the complex ductwork of a new $1.5 billion medical center a couple of blocks from San Francisco Bay. He hits a snag. A large air duct he is following has mysteriously disappeared into the side of a sprinkler pipe and reappeared on the other side. This is impossible, the building designers have to be informed. This has to be fixed immediately.
That’s easily enough done, because the duct doesn’t exist. Nor does the hospital. Khanzode is sitting at a computer terminal inside a double-wide trailer on the edge of the hospital construction site, which is currently bulldozed earth. The building and all its ductwork are merely bits of data in a 14-gigabyte file stored on a server. Khanzode homes in on the image of the air duct running into the pipe, clicks through the software, rotates the view and zooms in, as if playing a videogame. “In a normal process it would have taken a week to solve it,” he says. “Now we can do it in two minutes.”
Khanzode, the director of virtual construction for general contractor DPR Construction of Redwood City, Calif., is one of 120 people from 30 different companies who have spent the past 16 months virtually building a new 878,000-square-foot medical center for the University of California, San Francisco. Physical construction of the project won’t begin until December. Completion is slated for June 2014.
By building the medical center first in detailed 3-D graphic computer files, the designer and builders can discover problems when they’re easier and cheaper to solve. Already DPR and its collaborators say they have shaved five months off the schedule and $100 million from the budget.
“What’s important to us is predictability,” says Stuart Eckblad, director of design and construction for UCSF Medical Center. “We are confident that the building can be built as drawn. It used to be there was no certainty that those drawings were right.”
The leading edge of the construction industry has undergone a radical change in the last five years. The old way of building meant hiring a designer, putting the project out to bid, then bringing in the builder and tradesmen. The plumbing subcontractor would superimpose his set of drawings on a light table over those from the electrical folks and the heating and cooling tradesmen–in search of what the industry calls “clashes,” or problems. Inevitably, the design had to be reworked in places to allow the various systems to fit into their allotted spaces.
The new method, called virtual design and construction, brings the builder and a number of subcontractors into the process while the design is still in the works. For the UCSF medical center, architects at San Francisco firm Anshen & Allen began design work in March 2007. DPR was hired as the general contractor in August 2008. In March 2009 the mechanical, plumbing, electrical and other subcontractors began delivering their input to the computer model.