Because there is a growing awareness of the environmental benefits of modular construction for green building, the Modular Building Institute recently commissioned a report that specifically aligned the modular building industry with the prerequisite and credit requirements imbedded in the United States Green Building Council’s (USGBC) Leadership in Energy and Environmental Design (LEED™) building rating system1. The report particularly looks at LEED for New Construction and Major Renovations, applied to commercial construction, and LEED for schools.

2009 MBI Awards of Distinction Winner-Green Buildings
Waldorf School, Charlottesville, VA
Proven Green Features:
• Highly reflective roof membrane
• Increased R-value of building envelope (insulated doors, windows and a vapor barrier)
• Recycled materials, including exterior siding, floor and acoustical ceiling
• Dual glazed, Low E glass windows
• Daylight harvesting with sun tunnels
• Paperless drywall and no-VOC paint
• High-efficiency light fixtures (T-5s)
• Energy-efficient heat pump with reduced noise
• Placement for least impact on surface water movement

The report author— green building pioneer Robert Kobet—indicates that modular building offers significant opportunities for environmental stewardship and LEED certification particularly in the area of architectural engineering and construction choices. This article will summarize that report’s overall conclusions concerning modular construction and sustainability as it relates to the LEED prerequisite and credit categories: Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, Innovation & Design, and the new category for LEED 2009, Regional Priority2:

Sustainable Sites and Modular Building
Proper siting or placement of modular units can contribute to improved daylighting, natural ventilation, better storm water management, more efficient site lighting and a host of other sustainable design and development improvements that contribute to a more energy, material and resource efficient project. This category also rewards construction techniques that limit site disturbance and keep disturbed areas to within the areas immediately adjacent to the building footprint. Because modular building units are fabricated offsite and delivered by over the road transport it is possible to achieve tighter site control and less disturbed area in the project perimeter.

Water Efficiency and Modular Building
Water conservation and the LEED Water Efficiency credits are gaining in priority and application as the awareness of the importance of water and, in some cases, growing shortages emerge. Water conservation is one of the hallmarks of high performance green buildings and one area where modular building can enjoy the same benefits as conventional construction. All construction—whether conventional or modular— can include the principles, practices and products associated with water conservation and site water management. Rain water harvesting systems can be integrated into modular building designs. Ecologically sensitive landscaping, intelligent plant selection, and sensitivity to the microclimates buildings create when sited are universal principles and practices that apply to all construction.

Energy and Atmosphere and Modular Building
Increasing energy costs and growing concern about energy availability and security are sure to keep the interest in energy conservation and renewable or alternative energy sources in the forefront of the high performance green building movement. Modular building has a number of potential advantages:

• Modular construction that uses structural insulated panels or SIPS can produce relatively high R-values;
• Steel and aluminum stud frame construction can produce energy efficient units;
• High performance windows contribute to the pursuit of high performance building envelopes.

Modular manufacturers may also tout superior energy conservation and reduced operating costs as a function of quality control in factory environments, as opposed to conventional construction where both labor and materials can be subject to the influence of weather.

Materials and Resources and Modular Building
Modular building by nature is material and resource efficient. One of the great economies of modular building is the ability to assemble repetitive units in controlled conditions. Another is to minimize material waste associated with conventional construction due to weather intrusion and construction site theft. Modular components and subassemblies that exhibit controlled tolerances can be coordinated into larger projects. Whole modular units— largely finished prior to arriving at the construction site—can significantly limit construction waste generated at the site and contribute directly to construction site waste management.

Indoor Environmental Quality and Modular Building
Superior indoor environmental quality is one of the most desirable and important attributes of high performance. At this time, the modular industry can provide both environmentally conscious buildings and eco-friendly building materials because it has control over both the materials and quality control features that provide superior building atmospheres. This is evidenced by the creative and inspirational responses produced by modular building manufacturers who have participated in green building design challenges. They are proof positive the modular building industry can continue to pioneer and respond to the evolution of the green building movement.

This category also looks to the proper indoor air quality during the actual construction of buildings. In modular
building manufacturing plants the conditions are often ambient, reducing the need for supplemental space conditioning during construction. The assembly areas are not subject to excessive moisture or extremes in temperature and are generally controlled.

Innovation and Design Process and LEED
Perhaps the best feature of the LEED building rating system is the invitation to be innovative. It underscores that fact that all buildings, including modular buildings, are simply what we make them. Modular building capitalizes on the ability to move product in controlled manufacturing conditions, tight inventory control and project schedules. It is inherently waste conscious and can have minimum site impact if delivered carefully and strategically with respect to site constraints. Modular units purchased within 500 miles of the construction site offer other LEED point opportunities as does the reality of installing low VOC materials on site.

Regional Priority
The Regional Priority credits category is new to LEED 2009. The category was introduced in response to the USGBC members who felt LEED should evolve toward something that could address local issues. The Regional Bonus Credit category contains four possible Regional Specific Environmental Priority credits. A database of Regional Priority credits is available on the USGBC website (www.usgbc.org). It is recognized that modular building components and finished modular building units can be a part of any LEED design and construction effort, and as such regional priority credits can also be obtained. For example, if the location in which the modular building project has listed Energy and Atmosphere Credit One – Optimum Energy Performance (EA) as a Regional Priority Credit the team is eligible for a point via that Regional Priority credit opportunity if the team scores well in the EA point.

The evolution of LEED is a reflection of the changing market forces, ongoing innovation and opportunities that present themselves in the design, construction, and operation and maintenance of high performance green buildings. There is every opportunity for the modular building industry to identify with and achieve the value added in energy, material and resource efficient qualities and attributes of high performance buildings. At the same time the modular building industry offers the best strategies for construction waste management, material efficiencies and superior air quality.

Tom Hardiman is the executive director of the Modular Building Institute based in Charlottesville, Virginia. Founded in 1983, the Modular Building Institute is the only, international, non-profit trade association serving non- residential modular construction. To review a complete copy of the white paper, Modular Building and the USGBC’s LEED™ Version 3.0 2009 Building Rating System, visit www.modular.org.

1Modular Building and the USGBC’s LEED™ Version 3.0 2009 Building Rating System. Author, Robert J. Kobet, published by the Modular Building Institute, June 2009.

2Report conclusions for all categories taken directly from Modular Building and the USGBC’s LEED™ Version 3.0 2009 Building Rating System. Author, Robert J. Kobet, published by the Modular Building Institute, June 2009.