MBI and BD+C Modular Advantage | Spring 2011
Does the Offsite Construction
Process Equal Green?
Due to recent advances in technology and consumer awareness, there is a growing acceptance of the environmental advantages of offsite, prefabricated, and modular building systems.
Think of modular construction as a construction process rather than a type or style of building. The difference between offsite and traditional, onsite construction comes from where the building is built, not how. Sixty to 90 percent of commercial buildings are built offsite in a factory-controlled environment and transported and assembled at the final building site.
Due to the quality-controlled process, modular construction by nature is material and resource-efficient and allows for the following green benefits:
To earn one AIA/CES learning unit, read this article and the test questions, then submit your answers by clicking the Submit Test Answers link at the bottom of this page.
1. Understand that due to the
process used modular has
inherently green benefits.
2. Recognize what the green
benefits of modular
3. Learn about green, efficient,
innovative modular projects
that have been successfully
4. Learn how using controlled
environments to construct
buildings is not just
inherently greener, but also
healthier and safer.
1. Less construction waste
2. Design for deconstruction
3. Repurposing buildings for secondary locations
4. Fewer site disturbances
5. Improved indoor air quality
6. Reduced construction schedules
Less Construction Waste
Offsite construction makes it possible to optimize construction material purchases and usage while minimizing onsite waste. Since modular builders work in a factory controlled environment, they can have many construction projects underway simultaneously in one location, so they are better able to re-inventory materials that may have been allocated to one project, for use in another. With site built construction, a general contractor would send any overage to the recycle bin or to the dump.
Bulk material deliveries sent to the manufacturing facility are also stored in a protected environment safe from theft and exposure to the environmental conditions of a job site.
Design for Deconstruction
Modular buildings are also more readily designed for deconstruction. The fact that the modular building is assembled in modules means that it can be disassembled at the end of its useful life. Buildings can be reused by simply reversing the process in which they were installed on site.
One of the most sustainable concepts for the building industry is remodeling and reusing existing modular buildings instead of building new ones. Relocatable buildings have a useful life of approximately 20 years if properly maintained and permanent modular buildings can last over 60 years. Capital improvements can also extend the useful life of these buildings. Once the buildings have served their purpose in one location, they can be moved or reassembled to accommodate the next use.
Fewer Site Disturbances
Because of the unique offsite construction process, modular construction workers report to work at the same manufacturing facility rather than commuting to and from various construction sites. Once a project is completed in the factory, the building components are then transported to the site for installation. This process greatly minimizes the traffic from workers, equipment, and perhaps most importantly, suppliers. Rather than making multiple deliveries to the site, modular manufacturers buy in bulk with fewer deliveries.
Improved Indoor Air Quality
Many of the indoor air quality issues identified in new construction result from high moisture levels in the framing materials. Because the modular structure is substantially completed in a factory-controlled setting using dry materials, the potential for high levels of moisture being trapped in the new construction is eliminated.
Reduced Construction Schedule
With modular construction the site preparation and construction take place at the same time. This allows for most projects to be completed 30 percent to 50 percent sooner. This streamlined and efficient work process results in few labor hours needed per project, thus fewer trips to the site per project. Earlier occupancy of a building also allows for faster revenue generation.
Case Study Examples
High Tech High
Chula Vista, CA
The charter school had to meet strict indoor air quality, site design, renewable material and energy efficiency building standards in order to meet USGBC LEED®, Collaborative for High Performance Schools (CHPS) and ENERGY STAR® requirements. Building also had to be limited to certain areas of the site to reduce noise, pollution and habitat destruction. In addition, there was a tight budget and completion schedule for the project.
Various green materials were used to enhance classroom acoustics, day-lighting and energy efficiencies. The modular units feature various high-performance products including, dual pane windows with low-E coatings, acrylic skylights, light fixtures with motion controlled sensors and low volatile organic compound paint. The project also incorporated renewable and recycled materials such as sealed lightweight concrete floors, Homasote 440 Sound Barriers, which are high-density fiberboards made from recycled newsprint that help to control acoustics in walls, and a sprayed polyurethane roof. All the materials, with the exception of the interior casework, were available locally, further reducing the carbon footprint of the project.
The entire project was completed in only five months and the project includes 59 modular units totaling 32,807 square feet.
Photos courtesy Williams Scotsman
Pirate's Cove Restaurant & Bar
Prior to being utilized as a restaurant and bar, this building was originally an office complex used by the City of Burbank. This unit was built in 1975 and remanufactured in 2008 bringing it to current standards and modernization. Prior to the customizing of the unit, the interior was gutted and the building was taken back to an open shell which allowed for renovation.
The interior was completely renovated and all new finishes were applied. The building was designed to fit in well with the “beach like” scenery that surrounds it. Approximately 240 boaters dock at this location.
Once delivered, this building was ready for occupancy in three weeks. A site built unit would have taken four months from the time the jobsite was prepared and ready. The cost of a stick built unit would have been more than double the cost. The doors and dual pane windows are large and allow the right amount of sunlight in during the day which helps conserve electricity. The wall mount A/C units were removed and new higher efficiency roof mounts were installed.
Photos courtesy Pac-Van, Inc.
(Top left) photo courtesy Project Frog (top middle) courtesy ModSpace (top right) courtesy Britco Structures.
AIA Continuing Education Test
1. The term “modular” refers to a type or style of building.
2. Typically what percentage of commercial modular buildings
are built in the factory?
A. 20 to 30 percent
B. 50 to 60 percent
C. 60 to 90 percent
D. None of the Above
3. Which of the following are green benefits of offsite
A. Less construction waste
B. Repurposing buildings for secondary locations
C. Improved indoor air quality
D. All of the Above
E. None of the Above
4. Modular builders can have many construction projects
underway simultaneously in one location, so they are better
able to re-inventory materials that may have been allocated
to one project, for use in another.
5. Relocatable buildings have a useful life of approximately 60
years if properly maintained.
6. Once modular buildings have served their purpose in one
location, they can be moved or reassembled to
accommodate the next use.
7. Modular construction can have fewer site disturbances due to:
A. Fewer deliveries being made to a site
B. The amount of recycling that takes place on site
C. The proximity of the factories to a site
8. Rather than making multiple deliveries to the site, modular
manufacturers buy in bulk with fewer deliveries.
9. Because construction of the building can occur
simultaneously with the site work (or even before the site
work), the traditional construction schedule is significantly
compressed using modular.
10. In the High Tech High case study, which of the following
building standards did the charter school have to meet?
A. Strict indoor air quality
B. Site design
C. Renewable material and energy efficiency standards
D. All of the Above
E. None of the Above
In order to maintain high-quality learning experiences, please access the evaluation for this course by logging into CES Discovery at www.aia.org and clicking on the course evaluation link on the left side of the page.
SUBMIT TEST ANSWERS HERE
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