Georgia State Library’s ‘Link’ to BIM

by Tracy Ostroff
Contributing Editor

Summary: Like many great ideas in architecture, the crux of the program for Atlanta’s Georgia State University library renovation, with a glass bridge that spans historic Decatur Street to link two existing university buildings, was sketched out over dinner on a paper napkin. But, aside from just a few more hand-drawn designs, architecture firm Leo A Daly took this project digital and three-dimensional. As the architecture firm’s first fully produced building information modeling (BIM) project, the design process saved time, money, and logistical angst as the building team renewed the old buildings and reorganized the library collections in a way that was least disruptive to Georgia State students and faculty.

The Georgia project, funded through a student fee assessment, started out as a relatively typical state venture, says Leo A Daly Vice President and Managing Principal Jerry Voith, AIA. The task was to take the old library, which had become dingy, yellowed, and in some cases held together with duct tape, and turn it into a modern facility that would promote research and learning and sell the school to perspective students and faculty.

The site is at the heart of the urban, downtown campus. For the design, they took two formerly disparate buildings, one five stories tall and the other eight stories, and connected them via a light-filled, five-story, 60-foot-wide glass-enclosed bridge that crosses busy Decatur Street. The result of the renovation is a cohesive, expanded library that combines user-friendly amenities with a bold, colorful design of multifunctional spaces.

Using BIM
Almost from the beginning, Voith says, the team, working from its Atlanta and Omaha offices, developed the project using Autodesk’s Revit Building, and quickly began to build the model and troubleshoot it using the clash detection program NavisWorks to discover and resolve conflicts. The three-dimensional model helped the designers and client visualize the end result.

That process was good for the schedule and the bottom line. “The clash detection software allowed us to solve problems as they came up,” Voith says, and was particularly helpful in discovering conflicts between disciplines. A typical example, he explains, is when a duct occupies the same space as a beam. The computer work resulted in a minimal number of requests for changes, smoother construction contract administration, and a much smoother process.

And timing was of the essence. The school’s library team had to phase work around the students. They also had to move three million books three times while undertaking a reorganization of all the library’s collections, a feat Voith muses, they may have been able to digitize by inputting the volumes into the BIM software.

Streamlining
The firm worked to realize the program the school had developed by first evaluating and analyzing the site and talking to user groups about their library, two other buildings near the library, and landscaped plazas at different elevations that connected the buildings. Voith recalls: “The biggest generator of ideas was the site.”

Voith notes that the construction manager and structural engineer came on early in the process, a decision that allowed the team to sequence the erection of the bridge and efficiently close Decatur Street. The streamlined process helped the school save a little more than $500,000, Voith reports.

“BIM is the closest we can come to designing a building to the way it is actually built,” Voith says of the modeling software. It helped the team overcome several challenges with great success, the architects note, leading the project to win the AIA 2006 BIM Award. For example, the modeling software allowed the designers to study shading, reflectivity, and light. Designers were favoring a heavily horizontal glass façade, with glass-faced mullions to emphasize the linear path of the bridge, an approach that made the client hesitant. The more the architects investigated the scheme by manipulating the data in the model, however, the more they confirmed that a transparent strip of glass was the most pragmatic and efficient.

“It’s a huge tool for studying the impacts and a great tool for the owner to visualize the project,” Voith says. The designers’ intuition, supported by the models, is rewarded with client understanding and acceptance.

All BIM, all the time? No.
Voith says that although architects must come to embrace BIM, the technology does not have to be used on all projects, all the time. Some jobs just don’t call for that high a level of detail, and, beyond that, “we don’t want to lose sight of the ability to draw by hand,” Voith says.

BIM is a powerful tool in that it both “reveals a lot of the fallacies of ideas” and is a “quick way of communicating,” especially with clients, Voith notes. A lot has changed in BIM, even since the project was completed just a year ago, he encourages. The software is improved, the model library is more robust, and computers are faster and cheaper, making it easier and more reasonable to produce models.

For firms just starting in BIM, Voith says he might advise starting with a simpler project, rather than a complex renovation, particularly one with multiple buildings and areas. He also notes that contractor selection is “so important with a BIM project.” The contractor, he says, can be intimidated by the amount of quantitative data, which arms the architect with takeoffs for program changes. The software levels the playing field in discussions with contractors. Voith also notes that it is important to invite the contractor to participate as part of the BIM process, but notes that sharing model information and shop drawings may prompt some legal concerns with the more traditional project delivery approaches, which he hopes will be worked out in time.

His advice for firms that are thinking about taking the plunge, even those with fewer people and resources than Leo A Daly: “The world of BIM is the future. Get into it as fast as you can. But remember, don’t use a sledgehammer to drive a finishing nail.”