Glass High-Rise Era May Be at an End : Buildings: Designers attribute the decline in the once ubiquitous use of reflective glass to changes in taste and new materials.
Has the era of the anonymous reflective glass high-rise in San Diego come to an end? For a variety of reasons, those most closely involved with the design of tall buildings think so.
Citing demand from tenants and developers for better buildings, more stringent city design standards, the availability of better materials and the increased sophistication of architects, both architects and urban planners predict that reflective glass elephants such as the First National Bank and Wells Fargo buildings downtown will never rise again.
“I think there is a trend away from glass curtain wall construction,” said Max Schmidt, assistant vice president at the Centre City Development Corp., the city of San Diego’s redevelopment branch. Schmidt is also the CCDC’s urban design expert. “Symphony Towers was a departure. First Interstate Bank was too.”
Both these buildings combined glass with granite to set precedents for high quality, high-rise skins downtown; Symphony Towers at 7th Avenue and B Street, was designed by internationally known Skidmore Owings & Merrill and was completed in 1989, and First Interstate building at 5th Avenue and B Street, was designed by Welton Becket & Associates of Los Angeles and completed in 1984.
The best example of the advanced state of high-rise design in downtown San Diego is Chicago architect Helmut Jahn’s America Plaza, scheduled to open at Broadway and Kettner Boulevard this fall.
“We haven’t done a reflective glass building in a long time,” said Jahn, one of the nation’s best-known high-rise designers. As Jahn noted, the initial appeal of reflective glass, when it became available during the 1970s, was that it offered an energy-efficient skin at low cost. Such glass reflects a significant portion of sunlight, keeping a building’s interior cool without exorbitant air-conditioning costs.
“In terms of the new glasses, the same results can be achieved with less reflectivity or less tinting,” Jahn said.
“We tried to stay away from reflective glass, both because the city of San Diego frowned on it, and we ourselves have a preference not to use reflective glass,” continued Martin Wolf, a principal architect at Murphy/Jahn, the company of which Jahn is president. “In an urban situation, it does a fine job controlling direct sunlight and reducing energy costs, but it reflects things you don’t want it to reflect. Also, reflective glass accentuates distortions in the glass.”
The most common of such distortions is an effect architects call “pillowing.” Instead of appearing smooth, each glass panel on a building’s surface looks warped, or pillow-like.
“On America Plaza, we used blue tinted glass for the vision areas and patterned glass for the spandrels,” Wolf said. (“Vision” areas are the see-through panels next to interior office spaces. “Spandrels” are the opaque expanses of glass in between.)
America Plaza’s patterned spandrels are textured on the inside with a pattern of dots applied to the glass using a silk-screen method--a relatively new technique known as “fritting.”
The subtle patterns of light and dark created by the different types of glass, combined with the aluminum frames around the glass, lend detail and scale to the building.
Watch for the next generation of downtown high-rises to follow Jahn’s non-reflective, creative lead. A 1989 amendment to the Centre City Development Corp.’s Columbia Redevelopment Plan, which governs redevelopment projects north of Broadway, encourages developers to mix glass with other materials. According to Schmidt, developers who cover less than half of the surface of their buildings with glass, and the rest with stone, masonry, or another material, are eligible for “density bonuses” allowing them to build taller buildings.
How did some of those classic 1980s reflective-glass boxes get built in the first place?
San Diego architect C.W. Kim was responsible for two of them: the First National Bank (originally Columbia Centre) on Columbia Street and the bayfront Inter-Continental Hotel (now a Marriott Hotel).
The bank building was the first high-rise produced by San Diego developer Doug Manchester. Kim’s original design called for a skin of alternating bands of glass and aluminum panels, but Manchester insisted on glass, right down to the sidewalk, Kim said. This gives the building a cold, anonymous appearance, both from a distance and up close.
On Kim’s first Inter-Continental tower, also for Manchester, the glass manufacturer originally assured the architect that the 14-foot-long panes would bend to match the building’s curved contours. As it turned out, the glass had to be applied in straight sections that didn’t achieve the sweeping curves Kim was after.
The availability of affordable alternatives to reflective glass, and the willingness of developers to use them, both are apparent in Kim’s newest downtown high-rise design, the hexagon-spired Emerald-Shapery Center on lower Broadway, completed this year.
According to Kim, the building’s skin of tinted glass, granite and precast concrete panels cost about the same as the Columbia Centre’s all-glass skin did in the mid-1980s.
Back then, with few inexpensive alternatives, reflective glass was hard to beat, according to San Diego architect Charles Slert, who designed several glass office buildings during the 1980s.
“A lot of projects I’ve done that have used reflective glass have not been my choice,” Slert said. “I didn’t start out by saying I wanted to be a master of reflective glass. It’s been more a by-product of a point in time, relative to products and technology and economics.”
Even the 9444 Balboa office building near Interstate 15, an award-winning glass-skinned structure designed by Slert, wasn’t conceived as a glass building.
“It was originally going to be stucco with ceramic tile,” Slert said. “But to detail the building properly was too expensive--it was cheaper to do it with a glass curtain wall system. It wasn’t my preference, but the economics were so overwhelmingly superior that it could not be denied.”
Even in suburban areas, such as 9444’s neighborhood, there is no longer an excuse for nonstop reflective glass, now that affordable options are available. And in downtown San Diego, forces apparently have driven away the dread reflective glass for good. But that doesn’t mean architects have lost their fascination for experimental materials.
“Man-made materials always interested me,” Jahn said. “This is based on an education in thinking that technological materials are modern and natural materials are more conventional. That’s not true. Stone, which is an integral part of a tower wall, is just as technical as a piece of metal would be. In buildings like the one in San Diego, we explore the tension between natural and synthetic materials.”
Perhaps the most significant sign of progress in high-rise design is not the advent of new materials or an architect’s ability to use them gracefully. The true force behind better buildings such as America Plaza is the expanded consciousness of traditionally conservative clients, such as Great American, the bank that first hired Jahn. (In a transaction expected to be final next month, Great American is selling its 49% stake in the building to the Japanese Shimizu Corp., which already owns the other 51%.)
“We presented many different models and concepts for this building to Great American,” Wolf recalled. “Their reaction was a factor in the direction we took. They wanted a landmark building. They wanted to make a statement. That always drives us harder and faster and spurs us on creatively, to do something that will have some significance.”
