Governors Island is now open for the season, and soon, visitors to the park will be greeted by a brand-new building. The Friends of Governors Island asked an emerging firm to design a Welcome Center—a first for the island—to greet visitors disembarking from the Manhattan ferry. The structure, it said, had to be temporary, made of prefabricated materials, and if need be, the whole had to be designed to be re-erected on a different site. The timeline? Six weeks from concept to completion. "We were designing for that flexibility," said Stephanie Lin, co-founding principal of OFFICE III, a bicoastal architectural collective founded last year by three friends from the Harvard GSD. For this project, Lin, along with principals Ryan Golenberg and Sean Canty, looked to the island's defensive architecture for inspiration. The group was especially taken by the thick-walled Castle Williams, a red sandstone fortification—complete with gun casements—that looms over New York Harbor. Instead of defending itself from intruders, though, OFFICE III's Welcome Center—in keeping with its name—embraces the crowds. "It's almost literally a device for framing and filtering," Lin said. "While the castle keeps people out, the Center is a foil that brings people in." The structure's frank but expressive openness is meant to dialogue with the rolling hills and serpentine paths West 8 designed for Governors Island last year. An information kiosk and a retail cube form the core of the structure, while wood and polycarbonate windows segment a lounge area that provides refuge from the summer sun. With built-in seating, an 800-square-foot wooden deck that unfurls beneath the butterfly roof, and less than a foot of material separating the Welcome Center floor from the lawn below, Lin hopes the kiosk can host events that will flow naturally outside. For all its transparency, the structure isn't light on durability. Last year, more than half a million people visited Governors Island, with an average of 20,000 visitors each weekend. The interior's marine-grade plywood, patterned in radiant diagonals, can withstand wear from tens of thousands of feet, while the exterior panels are finished with resilient cedar decking. The larger panels were fabricated on-site, and the pieces will be reused in upcoming seasons. Formally, a series of two-by-12-inch wood louvers resist vertical loads, while the structural diaphragm (the core) resists lateral loads. In spite of its complexity, the entire building can be disassembled, all panels intact. The team collaborated with Laufs Engineering Design on the structural engineering and enlisted Steffan Elzinga of Wood Mgmt to help with construction. Although Governors Island officially opened yesterday, the Welcome Center will debut later this month. There's another new thing to see on the island, too: Team Aesop, the winner of this year's City of Dreams Pavilion competition, designed a crystalline shade structure from 300,000 melted aluminum cans.