In an era of tight budgets and sophiticated digital tools, architects take modular construction beyond the single-family house.
For the Star Apartments project, Guerdon Modular Buildings began assembling four prototypes of the units, which typically are 12 feet wide, 30 feet long, and 10 feet 6 inches tall, at its 225-employee factory in Boise, Idaho, in late August. According to Lad Dawson, the company's CEO, Guerdon has the capacity to build between four and six of Star's units each day and plans to deliver the first modules to the site by the middle of October. Meanwhile, workers from Westport Construction, the project's general contractor, have been reinforcing the existing building's structure and forming the multilevel, moment-framed concrete deck that will receive the modules.
It should take Guerdon about 20 working days to lift the modules by crane and install all of Star's units, stacking them in clusters of nine to 12 modules around outdoor spaces and joining them to each other with a variety of connection types.
The Star Apartment modules are built to withstand the loads of transport as well as the forces they will sustain once the project is completed and occupied. Their frames are made primarily of wood, but they have wall assemblies that include a composite material combining sheet steel and gypsum board to help the units resist shear forces, explains Tim Williams, MMA managing principal. Binding the units to each other also improves performance, explains Brad Smith, principal of BW Smith Structural Engineers, the firm's structural consultant. “Together they are seismically stronger,” says Smith.
As part of the BIM workflow for the modular B2 project, the architect and engineer are creating virtual subassemblies, inserting those into a module, and grouping the modules into apartments and floors. The team will be able to use the model to generate documents such as shop drawings, a bill of materials, and fabrication tickets.
Diagram courtesy Shop Architects