TRAVELERS TOWER II, built in 1981 as part of a high-rise offi ce complex in Southfi eld, Mich., originally was named aft er one of its cornerstone occupants, Travelers Insurance. Today, however, the name may better represent how well this building has traveled through time to the present day, aesthetically and functionally. A design element that has been a key to surviving the journey into a new millennium is a curtainwall of insulated metal panels and refl ective glass that looks as contemporary today as it did 27 years ago.
The panel-joinery system has evolved from the early design used on Travelers Tower II to a pressure-equalized design used in the mid-1980s and, finally, the current pressure-equalized and vented design.
The Travelers Tower complex consists of two companion buildings: Tower I, an 18-story structure that opened its doors in 1970, and Tower II, a stouter, 13-story, 339,000-square-foot (31500-m 2) building built a decade later. Th e commercial offi ce buildings are centrally located to provide easy access to and from major freeways and arteries. Santa Ana, Calif.-based Grubb & Ellis Co., the buildings’ owner, describes them as “a jewel in the collection of high-rise buildings in Southfield.” Located about 17 miles (27 km) northwest of Detroit, Southfield has approximately 27 million square feet (2.5 million m 2) of offi ce space; that’s more than the central business districts of Cleveland; Cincinnati; Detroit; Indianapolis; or Kansas City, Mo. Southfi eld is home to more than 9,000 businesses, including more than steel truss that became a dominant design feature,” Richards says.
“The east end of the project is on grade, and the west end is cantilevered over the parking deck and integrates the complex directly with the parking garage and the original tower.” Th e portion of the building over the roadway had to be fi re-rated, so a fi re separation was created between the tower and base. All four steel trusses and the soffi ts over the road were sprayed with a concrete plaster fi nish, and the steel columns for the trusses were encased in brick. Another fi re separation occurs where the tower cantilevers over the post-tensioned concrete parking deck. Upon entering Travelers Tower II, visitors step into an impressive 3-story lobby with a curtainwall supported by triangular steel trusses. A monumental 3-story stairway built of concealed steel components, with no columns or vertical supports, remains a dramatic focal point. 80 Fortune 500 companies. Yet it’s a relatively young city, incorporated in 1958. Since that time, it has grown from a rural farming community to a leading business center, populated by numerous skyscrapers and high rises, many located just minutes away from quaint residential neighborhoods.
Despite the diff erences in height and breadth, the two Travelers Towers maintain strong visual continuity through a kinship in exterior design. Both buildings are the work of architecture fi rm Rossetti and Associates, Detroit, and use steel panels with spandrels between each fl oor, as well as broad expanses of glass that off er unobstructed views of the city. “It was the planning and integration of the new with the old with the result of two phases of a project that appear as if they were constructed at the same time that give these buildings a timeless quality,” says David Richards, AIA, LEED AP, and principal with Rossetti and Associates. There are a number of architectural features of Travelers Tower II that were considered cutting edge for their time, and still are innovative today. First, the building is constructed directly over Central Park Boulevard, a busy four-lane roadway that splits the site in half.
“Rather than place the building on a limited site, it was designed to span the four-lane roadway, using a 2-storysteel truss that became a dominant design feature,” Richards says. “The east end of the project is on grade, and the west end is cantilevered over the parking deck and integrates the complex directly with the parking garage and the original tower.” The portion of the building over the roadway had to be fi re-rated, so a fire separation was created between the tower and base. All four steel trusses and the soffi ts over the road were sprayed with a concrete plaster fi nish, and the steel columns for the trusses were encased in brick. Another fi re separation occurs where the tower cantilevers over the post-tensioned concrete parking deck. Upon entering Travelers Tower II, visitors step into an impressive 3-story lobby with a curtainwall supported by triangular steel trusses. A monumental 3-story stairway built of concealed steel components, with no columns or vertical supports, remains a dramatic focal point.
Approximately 50,000 square feet (4645 m 2) of insulated fl at metal panels were used on the exterior of Travelers Tower II. Th e panel composition—foam insulation between face- and back-side steel sheets—essentially was the same in 1981 as it is today. Th e design of the joinery system, however, has evolved over time. It originally was designed as a vertically applied panel system. On Travelers Tower II, this panel was used horizontally as part of an architectural trend to express a linear appearance with fl at metal panels. To improve the weathering performance of the joinery system, the joint was redesigned in the 1980s to allow for a pressureequalization chamber to help keep water out of the joint. In the mid-1990s, the joint was further refi ned to incorporate a vented interlocking J-hook.
Th e improvements to the design of the panels in no way implies the original panels used on Travelers Tower II were underperformers. In fact, according to Richards, they have held up quite well; there has been no leaking, rusting or discoloration. Th e fi rst Travelers Tower used another type of formed metal panel that was no longer available when the second tower was built. “Using these panels for Tower II allowed us to easily match and integrate the elements of the original,” Richards notes.
“Also, it was an economical solution for this project because the material was well within our budget.” Th e longevity of the panels has further capitalized on the original investment. As the demand for green-building products has grown, the panels have evolved to further minimize their environmental impact. Today, the steel used to manufacture the panels contains as much as 26 percent post-consumer and postindustrial recycled material and is 100 percent recyclable at the end of its service life.
Th e foam insulation inside the panels is hydrochlorofl uorocarbon- free and 100 percent recyclable. In the 1980s, well before the Washington, D.C.-based U.S. Green Building Council launched the LEED rating system, sustainability wasn’t the major factor for material selection it has become today. Th ese panels, however, have an expected useful life of 60 years and are 100 percent recyclable at the end of their service life. Although the panels haven’t been in existence long enough to be put through a real-world time test, based on their performance thus far on Travelers Tower II, it’s quite likely they will endure for at least another 35 years before they’re recycled for use on another high-profi le building project.
Anne Balogh writes about architecture and metal construction from Glen Ellyn, Ill.
TRAVELER’S TOWER II, SOUTHFIELD, MICH.
OWNER Grubb & Ellis Co., Detroit, www.grubb-ellis.com
ARCHITECT Rossetti and Associates, Detroit, www.rossetti.com
INSTALLER H.H. Robertson, Ambridge, Pa., www.hhrobertson.com
EXTERIOR METAL PANELS 50,000 square feet (4645 m 2) of the Formawall insulated exterior metal wall system from CENTRIA, Moon Township, Pa., www.centria.com