Miller Hull created a "family" of related, but not identical, libraries for the King County, Washington, towns of Black Diamond (1), Snoqualmie (2), Fall City (3), and Carnation (5), and the Muckleshoot Indian Reservation (4). The buildings share a common plan diagram, have similar structural systems, and rely on the same palette of materials. However, roof shapes and the design of the elevations respond to the character of each library's unique surroundings. Photos: © Yoram Bernet (2); William Wright ( 1 , 3 , 4 , 5 )

Among the uninitiated, there are no doubt many firms that would like to move to BIM but are waiting for just the right project - one that is sufficiently complex to take advantage of the technology's potential benefits, but still straightforward enough to allow team members to become comfortable with unfamiliar tools. For two Seattle-based companies, architect Miller Hull Partnership and contractor BN Builders (BNB), a set of libraries for five small communities in King County, Washington, provided the perfect point of entry. The firms, now both almost fully immersed in digital modeling, won the contract for the group of projects as a design-build team in the spring of 2006. They completed the final library early this year.

For the client, the King County Library System (KCLS), a digital-model-based process was not a requirement. "BIM was a design and construction team initiative," says Adrianne Ralph, the library system's facilities design coordinator. Instead, KCLS's key priorities were controlling costs during a period of rapidly escalating prices for construction materials, and compressing the design and construction for the five projects into a schedule of about 30 months. The firm also hoped that the individual libraries would have unique features appropriate to their settings, but would share a common layout and organization, allowing staff to move easily among branches. In order to achieve these goals, it bundled the similarly sized facilities (all between 5,000 and 6,000 square feet, with construction budgets ranging from $2 million to $4 million) into one project, with BNB as the design-build lead.

To Miller Hull and BNB, the libraries, for the towns of Black Diamond, Snoqualmie, Carnation, and Fall City, and the Muckleshoot Indian Reservation, presented the ideal opportunity. Their relatively modest scale made them appropriate for trying out new technology. In addition, a shared digital model seemed a good complement to the design-build process to enhance communication and collaboration among the project participants from the earliest phases of the project through construction.

The buildings' similar features also promised to streamline both the modeling and construction process. All of the one-story libraries have a steel structure and share a common diagram in plan - a large rectangle for the public space, and open stacks attached to a much smaller back-of-house rectangle. But to make the buildings distinct from one another and give them expressions appropriate to their settings, the architects designed generous windows that responded to each site's solar orientation and clad the libraries in different combinations of cedar siding, fiber-cement panels, and concrete masonry. They also created a unique roof-truss shape for each. For example, Miller Hull designed Black Diamond Library so that it resembles a gabled barn because it is surrounded by land that is largely agricultural. But at Carnation, they chose to reinforce a strong existing street edge by bringing the building close to the sidewalk and giving it overhanging eaves.

Working with this adaptable kit-of-parts approach and Autodesk Revit (one of several BIM platforms on the market), the architects could transfer similar elements from one building's digital model to the next. This cut-and-paste strategy helped the team meet the compressed construction timeline. "We could have done this in CAD, but not with the same ease," says Ruth Coates, AIA, a Miller Hull principal.

The architects did experience a learning curve. However, they found benefits to working in BIM even with the first library. "By working in 3D, we were able to identify potentially problematic details early in the design process," says Will Caramella, Miller Hull project architect. One such detail was part of the back-of-house enclosure at Snoqualmie. Water penetration was a particular worry where the single-withe concrete masonry walls met the roof, he explains. But by modeling the detail and generating axonometric views, he was more readily able to understand the relationships among the required materials than he would have been if limited to 2D, he says.

Photo: Miller Hull Partnership