Bringing BIM to Public Buildings

Let's face it: The federal government does not have the greatest reputation for nurturing positive change in the private-sector industries with which it works. However, one federal agency, the U.S. General Services Administration, is defying that commonly held belief, through its encouragement of building information modeling, or BIM.

Since the 1980s, the GSA, which helps manage $500 billion in government assets (including vehicles) and oversees $1.6 billion in new buildings and reconstructions, has used its financial clout to push for excellence in public buildings; the GSA's Design Excellence program was responsible for bringing the likes of such design geniuses as Robert A.M. Stern, Thom Mayne, Antoine Predock, and Carol Ross Barney to design federal courthouses and office buildings—buildings that often became the most talked-about edifices in their respective cities.

In more recent times, the GSA's Public Buildings Service has been pushing 3D, 4D, and BIM in an effort to encourage architecture and construction firms to rethink the processes and deliverables they've produced for the last 50 years. That initiative is having a positive impact on the entire AEC industry.

Evidence of GSA's emerging role in BIM came when the GSA Public Buildings Service swept the 2008 American Institute of Architects Technology in Architectural Practice BIM Awards, taking top honors in four categories: creating stellar architecture using BIM, design/delivery process innovation using BIM, outstanding sustainable design using BIM and support for human use, and innovative program requirements using BIM.

“The GSA has been a tremendous champion for BIM and is providing a good role model for other owners in the industry,” said Markku Allison, AIA, resource architect for the American Institute of Architects' national office. “Owners are the only member of the project team that have the capability to require or demand practices on their projects.”

Allison said that, from the AIA's perspective, the “single most important thing” owners can do in the pursuit of better and more sustainable outcomes on their projects is to unilaterally require collaborative models, through the use of integrated project delivery and BIM.

That's what the GSA has been doing in the last few years. To date the GSA has advised Building Teams on more than 70 government building projects on BIM best practices, everything from assisting designers on using BIM software to assure spatial requirements are met, to adding scope-of-work language to contracts, to simply what BIM is and how it can be used. Since it began requiring a BIM spatial model for all its projects in late 2006, the agency has put 12 fully BIM-mandated projects on the boards.

“We've always tried to focus internally, but our mandate really gave a jumpstart to what people were doing with BIM in their design firms, and now we're seeing what the construction people are doing with it, working with their trades and doing clash detection and coordination,” said Stephen Hagan, FAIA, director of the Project Knowledge Center of the GSA PBS.

Hagan refers to this process as “seeding the marketplace” with ideas about BIM, rather than “strangling the marketplace” with BIM requirements.

To that end, the GSA makes no software- or program-deliverable demands of the design firms it works with; instead, it requires an industry foundation class (IFC) data model. An IFC is a neutral and open specification that is not controlled by a single vendor or group of vendors. It is an object-oriented file format with a data model developed by the International Alliance for Interoperability to facilitate interoperability in the design and construction industry.

The GSA has three BIM guides available on its website. Guide 01 explains 3D, 4D, and BIM to design teams. Guide 02 covers the spatial program validation that GSA demands of its projects. Guide 03 discusses 3D laser scanning for validation. The GSA hopes to introduce guides to 4D phasing and detailed energy analysis very soon.

“One of the big successes of our program was to engage the software industry early on, a whole bunch of vendors, not just one,” said Hagan. “We said, 'If you work with us and actually put into your software the requirements we're trying to accomplish, then we will put you in the guide and tell the industry that your software works for us.'”

Autodesk's Revit and Architectural Desktop BIM programs, Bentley MicroStation, Graphisoft ArchiCAD, and Onuma Planning System were all involved in the design of the GSA's 3D, 4D, and BIM guide and are included in it. Nemetschek's Vectorworks is currently in the process of getting into the guide. “We want to make sure the data we're getting is good data,” said Hagan. “How they do that is up to the designers and engineers, so long as it's good data.”

How BIM helped the GSA

The GSA's interest in BIM was born of economic necessity. In the 1970s, the GSA had a staff of 42,000; by 2003, the staffing level had shrunk to 13,000. (Today, the agency employs about 12,000, 5,600 of them in the Public Buildings Service.) PBS owns 1,500 buildings and builds or modernizes about 20 a year. Three decades ago, there was more PBS staff available to check drawings and ensure conformance to standards. A major cause of cost overruns was that space designed for GSA buildings exceeded the program. The U.S. Courts Design Guide defines occupant-based rules for U.S. Courthouse circulation design. In the past, GSA validated circulation design using visual inspection. The process was both time-consuming and error-prone. But by using BIM, GSA staff could check spatial models required for each of its projects in Washington, D.C., without visual inspections. Two hundred sixteen circulation rules were extracted from the U.S. Courts Design Guide and implemented in the spatial validation program that today requires a BIM model.

From there, the GSA's Office of the Chief Architect, headed at the time by Ed Feiner, FAIA (and today by Leslie Shepherd, AIA), launched an initiative to foster the use of BIM technologies. That program was a rousing success from both a cost-cutting and design excellence perspective. Some of the more notable projects:

300 NLA Federal Building, Los Angeles. A fully occupied federal building was guided through a 16-phase seismic upgrade and renovation project by using 4D modeling to reduce the overall schedule by 19%, while uncovering major errors in cost assumptions and communicating extensive move operations for tenant agencies.

“The 4D construction model of construction and tenant phasing revealed inefficiencies of schedule and communicated what the schedule needed to look like to the contractor,” said Peggy Ho, a leader in the GSA PBS's 3D/4D BIM program.

GSA Central Office Building, Washington, D.C. BIM and IFC data enabled direct model exchange with a consultant for energy analysis of this existing office building. A DOE-2-based program was employed to model energy use based on occupancy activities across a typical work day.

U.S. Courthouse, Portland, Ore. 4D modeling integrated design intent, structural engineering, and construction scheduling into one model to foster GSA communication to the public, tenants, and contractors for a seismic upgrade, including base isolators for a historic landmark courthouse building.

“The community there was concerned about preservation of this historic building, and the 4D model allowed the public to see what would happen to it,” said Ho. Initial bids on this project came in high, she said, but second-round bids came in lower, in large part due to the use of BIM.

GSA estimated that the cost savings on just one of the nine pilot projects offset the cost of conducting the two-year pilot program. That set the stage for the agency mandating a BIM spatial model on all its new projects in November 2006.

“On the projects we've done with BIM, we've seen better efficiency and quality,” said Ho. “We're able to give better feedback to our A/Es on their designs to insure they're meeting all our requirements, particularly the spatial program validation that makes sure the square footage is aligned with what we're requiring from them.”

Since GSA projects typically take six to eight years from concept to completion, the projects that began in 2007 under the BIM mandate are still in the early stages. However, many recently completed GSA projects that either used BIM without it being required or were in the pilot project have shown design innovation and efficiency.

Merging with Green Design

The new 587,000-sf Social Security Administration Payment Processing Center in Birmingham, Ala., was built using a BIM (Revit) spatial model and achieved LEED Silver certification, thanks in part to the modeling done by lead designer and architect HOK. Builder/developer Opus West of Tampa, Fla., which served as structural engineer, architect of record, and design-build contractor, completed the project in late 2007.

Early in the design process, HOK used BIM to figure out a way to take advantage of the building's north-south orientation to capture as much natural light as possible to increase energy efficiency. The model also ensured that no building occupant would be stationed more than 40 feet from a window. The facility's 8,500-sf green vegetated roof is the first in Alabama.

Opus (through its Opus Northwest office) also developed and constructed the EPA's 305,000-sf Region 8 Headquarters in Denver. The project, designed by architectural firm Zimmer Gunsul Frasca of Portland, Ore., was completed in late 2006. ZGF and Opus architects and engineers did energy modeling using Ecotect in the design phase to come up with the best energy scenario for the EPA and GSA's “walking the walk” project.

Four massing options were modeled with Ecotect (which was acquired by Autodesk earlier this year) to create rough energy calculations, including monthly heating and cooling use. A sample level was studied to examine daylight distribution across the floor plate. A matrix of the study results showed the advantages and disadvantages of each massing scheme. Thanks to the Ecotect modeling, the team decided on a square building surrounding an internal atrium design that ended up being the $90 million, LEED Gold building's final configuration.

The successes of planning green designs using BIM have been so robust for the GSA that the next design guide they'll be adding to the GSA website will be an energy analysis and green building guide. It is expected to be available on the GSA Web site this month.

“Understanding how BIM-based energy and thermal performance analysis can give feedback to designers and make our buildings more sustainable is a big push,” said Ho. She added that GSA is also looking at three early concepts of design analysis tools with researchers at Georgia Tech. One of these will eventually be chosen as the final concept.

To assist Building Teams working on GSA projects in each of the agency's 11 regional districts, the PBS has also set up a BIM champions list to give them direct access to experienced project managers and BIM leaders at GSA.

BIM creep at other government agencies

The GSA's BIM efforts have caught the eye of other budget-conscious government agencies, notably the U.S. Army Corps of Engineers (see p. 30). Hagan said the Veterans Affairs Administration, which is dealing with a huge program for capital construction to repair or upgrade its hospitals, is looking at BIM solutions. The State Department has mandated BIM for its overseas office buildings. And the states of Massachusetts and Wisconsin now have BIM pilot programs.

GSA BIM experts have cautioned their colleagues in other federal agencies to take a cautious approach as they did back in 2003. Hagan also noted that the use of BIM is still in its relative infancy in the design and construction fields.

GSA's Peggy Ho said many factors need to be considered with regard to using BIM in government projects. “Building Teams need to be able to choose the right technologies to use on the project,” she said, technologies that “fit the challenges presented.”

Timing, scheduling, and budget considerations need to be aligned to reap the rewards of the BIM process, said Ho. “If any one factor isn't there, it makes it harder for BIM to work,” she said. “Before we get too gung ho on saying 'BIM will solve all our problems,' Building Teams need to know that.”