Best Small Project (Under $10 Million)
The federal government designated 30 islands near downtown Boston as Boston Harbor Islands National Recreation Area in 1996, a type of national park. But, despite this stature, few people were aware of its existence.
The National Park Service and Boston Harbor Island Alliance, a local advocacy group, banded together to change that. The result is this $4-million, 6,000-sq-ft waterfront pavilion whose sinuous shape was designed to call attention to the islands while serving as their gateway.
With a pair of curvy concrete canopies that create a waterfall during heavy rains, the structure contains a ticket booth for ferries traveling to the islands. Lighted kiosks provide visitors with information about the animals and plants they might discover on their trip. Solar panels line the edges of the roof, and a 2,000-sq-ft harbor map spreads across the pavement.
The delicate folds that form up the roof spouts—inspired by the thin edges of the MacBook Air laptop computer—are made of double-curved reinforced concrete. This approach has been used rarely since the 1950s due to its high labor costs, says structural engineer Simpson Gumpertz & Heger. But instead of making the curves by hand, the team used 3-D modeling software and robotic arms that can turn on five axes. The concrete was created off site, eliminating the need for the costlier cast-in-place option, the firm says.
"The pavilion was sited and designed by carefully studying a digital model of the structure from a variety of vantage points that included the surrounding urban context," Simpson Gumpertz & Heger says. "The curved pavilion roofs guide rainwater through the structures into a catch basin, which is then used in an irrigation system to water the adjacent lawn."
The structure took a year to build, including a three-month shutdown in the winter to save on labor costs, which helped the project come in under budget.
Other challenges were site-based, Simpson Gumpertz & Heger says. The pavilion sits on a landscaped 20,000-sq-ft parcel atop the Central Artery Tunnel, also known as the Big Dig, and there is less than 4 ft of space between the tunnel's roof and the ground. Thus, strict loading limits were placed on the project, meaning heavy equipment could be used only sparingly. All subgrade infrastructures had to be carefully placed to avoid going too deep in the ground.
The pavilion, located amid the Rose Fitzgerald Kennedy Greenway, is the first structure to be built over the tunnel. It was intentionally located within sight of Faneuil Hall, the popular landmark, so that its wavy forms would pique the curiosity of tourists.
Boston Harbor Islands Pavilion, Boston
Owner/Developer: Boston Harbor Island Alliance
General Contractor/Construction Manager: Turner Construction
Lead Designer: Utile
Civil Engineer: Vanasse Hangen Brustlin
Structural Engineer: Simpson Gumpertz & Heger