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’s) 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.

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 following LEED prerequisite and credit categories: Sustainable Sites, Water Efficiency, Energy and Atmosphere, Materials and Resources, Indoor Environmental Quality, and Innovation & Design2.

The power of modular construction.
Pictured above is a completed renovated modular project.
The before picture is shown below.
The entire shell of the mobile office was reused.

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 buildings are fabricated offsite and delivered by a variety of 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 is one of the hallmarks of high performance green buildings and one area where modular building can enjoy the same benefits as conventional construction. Rain water harvesting systems can be integrated into modular building designs. Ecologically sensitive landscaping, intelligent plant selection, integrated pest management 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 over conventional construction in this category:

• Modular construction can produce relatively high R values and low infiltration rates if fabricated and constructed with good quality control;

• Steel and aluminum stud frame construction can also produce energy efficient units if care is taken to insure proper installation techniques and air sealing;

• High performance windows contribute to the pursuit of high performance building envelopes in each case, as do proper air sealing procedures and quality entrance systems.

Modular building manufacturers can also point to 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
One of the significant economies associated with modular construction is the ability to manage construction waste. LEED rewards construction waste management at the construction site by being able to account for the materials, by weight or by volume, that are diverted from landfills. This includes all non-hazardous materials excluding cut and fill and organic material removed from the site. One direct benefit of reducing the overall waste stream is the simplification of construction waste management at the site and the attendant reduction in dumpster costs and hauling fees. In the case of modular building, overall construction waste generated at the site can be reduced significantly.

Facility managers and architects are becoming
increasingly aware of the sustainable benefits
of the modular construction process.

Indoor Environmental Quality and Modular Building
Superior indoor environmental quality is one of the most desirable and important attributes of high performance. The modular building industry 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 challenges. Several modular building providers have won competitions for their buildings that demonstrate superior indoor air quality is possible with informed design and construction choices and quality construction.

This category also looks to the proper IAQ 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 to provide acceptable working conditions.

Innovation, Design Process and LEED
Perhaps the best feature of the LEED building rating system is the invitation to be innovative. It underscores the 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.

Modular capitalizes on the ability to move
product in controlled conditions with tight
inventory control and project schedules.

An Industry Building Green
Facility managers and architects are becoming increasingly aware of the sustainable benefits of the modular construction process. With greater numbers of government agencies and end users requiring facilities to meet energy efficient performance standards, such as LEED™ or CHPS™, modular construction can offer significant advantages over stick-built construction. In fact, many companies in the modular industry recycle entire buildings for different applications. “Renovated reuse” describes a module or modules that have been renovated to make up the core space of a new facility, offering significant material and waste savings.

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, nonprofit trade association serving non-residential modular construction. For more information, visit www.modular.org. Robert Kobet, AIA, is president of Sustainaissance International Inc., a multifaceted architectural consulting firm specializing in sustainable design and development and environmental education. Beginning in 1977, Bob has specialized in environmentally conscious architecture and allergy free non-toxic design for a variety of clients evolving a practice with projects in eight countries on five continents. For more information, visit www.bobkobet.com.

1 Modular Building and the USGBC’s LEED™ Building Rating System. Author, Robert J. Kobet, published by the Modular Building Institute, June 2008.

2 Report conclusions for all categories taken directly from Modular Building and the USGBC’s LEED™ Building Rating System. Author, Robert J. Kobet, published by the Modular Building Institute, June 2008. For the detailed assessment of each prerequisite and corresponding credits, please download the entire report from modular.org.

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