The word “modular” may conjure images of job-site trailers and portable classrooms. But permanent modular construction is a different animal, one that has benefited considerably from the integration of 3D and 4D design software. Modular design and construction can be a profitable strategy for Building Teams if they approach each project as a collaborative effort, work with experienced manufacturers, and remain open to bold new ideas.
Modular construction also has a strong green component because stringent factory controls ensure that materials are used more efficiently, generating less waste. Production is unaffected by weather. Modules are delivered to the site 80-90% complete, thereby accelerating the construction schedule and slicing costs.
Hotels, college residence halls, hospitals, and military facilities are among the types of projects that can utilize permanent modular construction. Most multi-story modular buildings are a hybrid of modular and site-built, with the repetitive elements (such as student rooms) preconstructed in the factory.
Modular buildings must meet the same building codes and architectural specifications as their conventional counterparts. Government buildings can be engineered to comply with the U.S. Army Corps of Engineers’ strict requirements as well as Anti-Terrorism Force Protection Requirements.
Lastly, modular construction works well with BIM because it is carried out in a controlled environment, where the process already integrates systems, materials, and labor flow.
“Modular building has come a long way in meeting interior air quality concerns, designing for daylight, and combining environmental stewardship and economic opportunity,” said Robert J. Kobet, AIA, LEED Faculty, president of The Kobet Collaborative, Pittsburgh. “It’s at the forefront in construction-waste management and is not limited in integrating modern technology, controls, building space conditioning, water, security, or any other technology-driven interest.”
The innovative buildings showcased here are winners in the “Permanent Modular” category of the Modular Building Institute’s 2011 Awards of Distinction, with comments from Kobet and three other judges: Mohamed Al-Hussein, PhD, PE, Associate Professor, Department of Civil & Environmental Engineering, Hole School of Construction Engineering, University of Alberta, Canada; Jim Jones, PhD, Professor, School of Architecture & Design, Virginia Tech University, Blacksburg, Va.; and Lorenz Schoff, PE, President of Energy Efficient Solutions, Blacksburg, Va.
1. Modular construction can fit into the local context.
Three new residence halls at Bryn Athyn (Pa.) College emulate the design vocabulary of other campus buildings with their cut stone, brick and stucco façades, and copper trim and gutters. Faux chimneys were prefabricated entirely off site to serve the lower-floor laundry room and carry mechanicals from the basement to the third floor. Dormers were also built in the factory and installed on site with the roof.
“It looks like an old English home that was turned into a dormitory,” said Schoff. “Most people would think it’s a site-built house.”
NRB (USA) Inc., Ephrata, Pa., manufactured the three-story, 8,114-sf buildings, each of which contains six apartment-style suites. A center stairwell opens up two stories to display a large, cathedral-style chandelier.
Schoff also praised the Fort Bliss Military Police Unit Operations Facility in El Paso, Texas. Because the 14,591-sf facility is located in a historic district, the contractor, Ramtech Building Systems, Mansfield, Texas, had to coordinate with the architect and the Fort Bliss historian on the building profile as well as the exterior. The façade is a combination of masonry and synthetic stucco across the gable ends of a site-installed, standing-seam roof. The facility was completed in 364 days.
2. Modular projects can provide quick turnaround.
Delivering a 520,000-sf project in 134 days might seem unattainable, but Warrior Group, Desoto, Texas, and Clayton Building Solutions, Maryville, Tenn., did so with the Medical Education & Training Campus (METC) at Fort Sam Houston, Texas. The two four-story complexes and 682 modules were being manufactured even as site work was getting started. Thanks to close collaboration on scheduling and transitions by the project team, virtually no costly rework had to be done on site.
The contemporary-looking exteriors of split spaced block and stucco are U-shaped to capture views from the windows. “The innovation was in using modules to surround a large space and create courtyard areas,” said Al-Hussein. Lower floors contain offices, classrooms, laboratories, and common areas, with living quarters above.
3. Modular design can create new ways to raise the roof.
The owner of the Pioneer Meadows Montessori School in Ferndale, Wash., a retired architect, wanted the advantages of modular construction in a contemporary-style building with vaulted ceilings. Modern Building Systems, Aumsville, Ore., fabricated the 1,176-sf structure as two modules. The roof was built entirely in the factory and hinged so it could be transported on lowboy trailers in the down position, passing easily under bridges. Once delivered to the site, the crew had only to lift the roof into position, reducing on-site construction time by at least a week.
“The hinged roof was a rather innovative idea because it gives you spatial dynamics as well as daylight integration, while still having the walls function for storage,” said Jones.
The job took 86 days, allowing the client to get the school opened quickly and save on lease payments.
A similar approach was taken with the Residential Education Center in Madison, Conn. A media center with 16-foot ceilings, plus additional classrooms, were added to the existing school. Modules were preassembled and the framework transported over roads with a height restriction of 13½ feet. At the site, the main module was lifted onto the foundation by crane and the roof was raised to its 16-foot height, using a four-inch-over-three-inch telescoping column system that was welded in place before the prefabricated, prewired walls were installed.
ModSpace of Berwyn, Pa., and Mobile/Modular Express, Edgewood, Md., completed the 7,811-sf project in 270 days, allowing the school to accelerate its plans for increased enrollment.
4. Modular designs can make building green even greener.
All new federal government buildings must now meet LEED Silver standards, but so are many private-sector projects. “Modular building can provide a cost-competitive way to do this,” said Kobet.
For its new office annex in Charlottesville, the University of Virginia Medical Center wanted a LEED Silver building that would save 50% in costs and 67% in design and construction time compared to conventional methods.
The 11,340-sf annex had to be installed in a very tight space. “The second-floor elevated walkway, built so that construction wouldn’t interfere with hospital traffic, is really an interesting and unique concept,” said Al-Hussein.
Flooring, cabinetry, and ceiling components were selected for their high recycled-material content. The bright white exterior panels, which match the façade of the medical center, consist of two sheets of corrosion-resistant aluminum permanently bonded to an extruded thermoplastic core.
To boost energy efficiency, Mobilease Modular Space, Thorofare, N.J., and Comark Building Systems, Desoto, Texas, installed sunshades, a white thermoplastic polyolefin roof, 16 SEER Energy Star rooftop heat pump units, and an enthalpy wheel—a rotary air-to-air heat exchanger—with MERV 15 filters. The building took 151 days to complete.
5. Modular systems can work well with rough terrain.
The UCSF Kirkham Childcare Center was designed and constructed to accommodate the sloping hills and steep grades of San Francisco. Some of the building’s architectural features, while common in site-built construction, are unusual for modular design.
For example, modules of varying sizes were used to break up the vertical and horizontal planes and give the two-story building a staggered silhouette. Pop-outs and cantilevered balconies maximize interior hallway space and add visual interest and functionality.
Kobet said the 6,700-sf facility puts aesthetics front and center. “Architects are beginning to see that modular construction can provide energy-, material- and resource-efficient solutions in ways that complement existing context while providing design flexibility and aesthetic diversity,” he said.
Pacific Mobile Structures, Chehalis, Wash., and Walden Structures, Mentone, Calif., installed all 18 modules in a single weekend on a concrete masonry unit foundation. The entire project was completed in 259 days.
BD+C A Quintet of Modular Building Innovations
- Modular construction can fit into the local context.
- Modular projects can provide quick turnaround.
- Modular design can create new ways to raise the roof.
- Modular design can make building green even greener.
- Modular systems can work well with rough terrain.