Tall buildings make the most lasting impression, but low-rise structures are the workhorses of the U.S. office building market. Buildings of six stories or less constitute 82% of the multi-tenant properties in the 53 metropolitan areas monitored by Torto Wheaton Research, the Boston-based business unit of real estate services firm CB Richard Ellis, Los Angeles.
Torto Wheaton Chief Economist Jon Southard also notes that Building Owners and Managers Association International (BOMA) considers "low rise" to be buildings of less than seven stories. Within the industry, there is general, but not uniform, agreement.
Randolph Tucker, senior vice president of building code consultant RJA Group Inc., Chicago, says that while there is no specific definition of "low rise," building codes have traditionally indicated a break point at about six stories. "High-rises are defined, and low-rise is everything that is not high-rise, unless you want to consider a mid-rise definition," he adds. The upper limit of "low rise" is essentially determined by building height and the ability of the fire department to gain access to the highest occupied level. "Anything above 60 feet to 75 feet, depending on who is defining, becomes a high-rise," Tucker says.
Interestingly, however, some code provisions specify more stringent fire-resistant ratings for buildings of four stories, Tucker notes. They provide that buildings of up to three stories need one-hour shaft enclosures, while two-hour enclosures are needed for buildings of four or more stories. Buildings with more than six stories generally require high-rise code compliance, which includes more costly upgraded fire alarm and smoke evacuation systems.
Gary Fowler, a principal with architect Thompson, Ventulett, Stainback & Associates (TVS), Atlanta, says low-rise office buildings are "aesthetically challenging, given the formulas of floor plate size, lease depth, floor-to-floor height and rent-to-construction cost. They [often] result in very boxy buildings. Fee-wise, they are more challenging than a slightly taller building because design fees are generally calculated on a cents-per-square-foot basis. These low-rise buildings require virtually all of the decisions required for a 10-story building, but within the parameters of a much smaller fee."
Mike Medici, the Phoenix-based president of southwest operations for A/E SmithGroup, Detroit, believes the challenge of designing low-rise office buildings involves larger footprints that require careful circulation studies. But the larger footprints of low-rise buildings — which can range from 20,000 square feet to 50,000 square feet — offer an advantage for organizations that want to keep operations on a single level. By contrast, high-rise office buildings generally can provide floor areas of only 20,000 square feet to 24,000 square feet.
A curved plan and an attractive lobby were two approaches used by SmithGroup to give distinction to the four-story Jackson National Life Insurance headquarters in Okemos, Mich. The building’s front elevation mirrors the edge of an adjacent woods.
"The greatest challenge in designing low-rise office buildings probably is providing quality and/or innovative design within a very tight budget," says Eugene Montezinos, another TVS principal. "There are a lot of low-rise office buildings and a lot of developers and architects doing them. Making them distinguished is difficult. They tend to be formulaic and repetitive. Quality design is often overlooked, as the bottom line cost is more important. Low-rise buildings must be more cost-competitive due to their smaller size as well as a more competitive market. A larger project may be able to support higher-quality materials, a larger lobby space or a signature building feature based on a smaller incremental cost per square foot."
Enhancing the "entry experience"
Steve McConnell, design principal with architect NBBJ, Seattle, says the big challenge — and opportunity — of designing low-rise office buildings is giving them an identity. He concedes that for a speculative project this may be limited to providing an attractive lobby that enhances the "entry experience." For a corporate facility or a building that houses a single tenant, the options are much greater, and include unique landscaping. The optimum solution is to develop a design inspired by the character of the building occupant. McConnell cites the active, sports-theme underlying the design of Reebok International headquarters in Canton, Mass. (BD&C, 1/01, p. 26).
Jeff Barber, vice president in architect Gensler's Washington, D.C., office, says building height is generally not driven by aesthetics. A developer is evaluating factors such as floor area ratio and the amount of surface parking needed. At the same time, he is weighing the project scope — a smaller one that is more easily financed, or one with excess capacity of which a single tenant will take a large portion.
SmithGroup and developer The Alter Group, Skokie, Ill., are among firms that are gearing up to serve the hoped-for return of build-to-suit development. Alter Senior Vice President Russ Posey says the firm's pre-designed office building packages are adaptable for most users.
In a market that offers minimal commercial opportunities, NBBJ is working with traditional commercial developers that are using a "smart shell" product that can provide either traditional office space or space for rapidly growing biotech companies. McConnell says NBBJ has discovered that a majority of biotech companies don't need all the features of top-of-the-line laboratory buildings. Using "smart shell" designs that include pre-plumbed components, these developers are "reinventing" their office buildings to incorporate laboratory requirements of biotech firms. NBBJ is working with developer Lowe Enterprises, Los Angeles, to develop buildings that can serve either typical office tenants or be upgraded for biotech companies. "Usually you can downgrade a building, but not upgrade it," McConnell observes.
Low-rise but distinctive
Two recently completed projects — 909 Davis Street in the Chicago suburb of Evanston, Ill., and Highlands Plaza Building One in St. Louis — illustrate that low-rise buildings and good design are not incompatible.
Robert Bunda, lead designer with 909 Davis architect, OWP&P Architects, Chicago, explains how an essentially rectangular building plan was modified so it would not present a boxlike appearance. The design was largely a response to a trapezoidal site created by the alignment of adjoining train tracks. An existing pedestrian circulation path between the building and the tracks was acknowledged by curving the building's west elevation.
The building faces north, but the office entrance faces south and opens onto a pedestrian plaza that connects two train stations. An angled element at its southwest corner provides a departure from the building's rectangular plan and also creates a recess for the main entrance. A two-story-high projection facing north both reduces the building scale and accommodates first-floor retail tenants.
Early design schemes suggested a five-story building, but this would have encroached on the pedestrian corridor, Bunda says. The design scheme was therefore increased to six stories to accommodate the 245,000-sq.-ft. program.
Highlands Plaza Building One is a speculative office building that is the first of several planned buildings on a 25-acre site in St. Louis. Local developer Balke Brown Associates challenged architect Mackey Mitchell Associates, St. Louis, to design a building "that looks to the future more than to the past," according to John Guenther, the project designer. The building's undulating roofline was inspired by the roller coaster of an amusement park that formerly occupied the site.
An undulating roofline helps the five-story Highlands Plaza Building One in St. Louis, break away from the stereotypical boxlike design of low-rise office buildings. Developer Balke Brown Associates wanted a “strikingly different” design that would capture the attention of motorists on an adjacent expressway.
"We didn't think we were pushing the envelope all that much," Guenther adds. "To achieve a smooth curve was certainly one of the challenges. It was simply a matter of varying the bearing points of the steel structure."
As he has demonstrated with the Highlands Plaza project, Guenther believes that a building's silhouette against the sky provides opportunities for creating interesting profiles, such as a pitched roof or a flat roof with significant overhang.
He says it is particularly important for low-rise office building projects that designers from the outset attempt to create a sense of place, turning away from the stereotypical building surrounded by parking areas. At Highlands Plaza, for example, the buildings will face a central park and all parking will be restricted to the perimeter of the site.