The need to decrease energy usage and subsequent emissions from the building sector has been at the forefront of U.S. green movement. Not only has energy reduction been viewed as a step for improving the environment, it has financial benefits for companies and homeowners.
To address this, researchers at the Massachusetts Institute of Technology’s (MIT) Concrete Sustainability Hub conducted a life-cycle assessment (LCA) study to evaluate and improve the environmental impact and study how the “dual use” aspect of concrete – its ability to offer a durable structure while providing thermal mass benefits for energy loads – affects the environmental footprint of the structure.
"Methods, Impacts, and Opportunities in the Concrete Building Life Cycle" provides a comprehensive analysis that advances three key areas relevant to the buildings LCA field: methodology, benchmarking, and impact-reduction opportunities. The study is a major development for construction-related life-cycle assessment because it thoroughly examines all phases of the complete life cycle of a building – from acquisition of materials to construction, the use of the building, and finally demolition and end of life.
“Most environmental assessments do not move beyond the construction phase and only provide a partial picture of the full impact a particular material can have on a building. This is short-sighted,” David Shepherd, director of sustainable development for the Portland Cement Association (PCA) said. “The heating, cooling, and general operations of buildings and homes in the United States accounts for approximately 70 percent of national energy consumption each year and an accurate LCA needs to include the operational phase.”
Concrete, essential for the construction of buildings and homes, has largely been chosen as a building material for its structural properties rather than its energy-saving properties. Although sustainable builders have known the thermal mass attributes of concrete significantly reduce heating and cooling needs, the energy consumption required to produce its key ingredient, cement, has raised questions about its environmental viability.
In its environmental assessment, MIT researchers found concrete homes produce lower greenhouse gas emissions than current best practice code – compliant wood-frame residences throughout a 60-year service life.
Concrete homes did have a higher embodied global warming potential (GWP) associated with the pre-use phase of LCA when raw materials are harvested and turned into construction materials, transported to the site, and assembled into the finished home. However, this phase accounts for only about 2 to 12%of the overall global warming potential for the life of the home. For the 60-year period of the study, houses constructed with insulated concrete forms have 5 to 8 percent lower GWP than current code compliant light frame wood houses, based on greater thermal mass and higher R-values. Researchers found similar results when evaluating multifamily residences.
Commercial office buildings built with a concrete structural frame produce slightly less greenhouse gas emissions over a 60-year service life than commercial structures built with steel frames, based on the results of the comprehensive MIT assessment.
MIT researchers then evaluated strategies to lower a concrete building’s carbon footprint and overall environmental impact. A major advancement was the incorporation of a cost-impact analysis to determine whether or not a given environmental reduction strategy made economic sense. Among the strategies evaluated, the two that reduced embodied emissions – increased fly ash and reducing the thickness of concrete walls from a 6-inch to a 4-inch concrete core – were found to be both economical and effective ways to reduce emissions. BD+C
Related Stories
| Nov 7, 2014
Prefab helps Valparaiso student residence project meet an ambitious deadline
Few colleges or universities have embraced prefabrication more wholeheartedly than Valparaiso (Ind.) University. The Lutheran-based institution completed a $27 million residence hall this past summer in which the structural elements were all precast.
| Nov 7, 2014
World's best new skyscraper: Sydney's vegetated One Central Park honored by CTBUH
The Jean Nouvel-designed tower tops the list of 88 entries in the 13th annual Council on Tall Buildings and Urban Habitat Awards.
| Nov 7, 2014
NORD Architects releases renderings for Marine Education Center in Sweden
The education center will be set in a landscape that includes small ponds and plantings intended to mimic an assortment of marine ecologies and create “an engaging learning landscape” for visitors to experience nature hands-on.
Sponsored | | Nov 6, 2014
To build your strongest team, don't hire clones
To attract and keep talented individuals who are different than you, Entrepreneur magazine suggests a few foundational principles. SPONSORED CONTENT
| Nov 6, 2014
Hines planning tall wood office building in Minneapolis
The Houston-based developer is planning a seven-story wood-framed office building in Minneapolis’ North Loop that will respect the neighborhood’s historic warehouse district look.
| Nov 6, 2014
Studio Gang Architects will convert power plant into college recreation center
The century-old power plant will be converted into a recreation facility with a coffee shop, lounges, club rooms, a conference center, lecture hall, and theater, according to designboom.
Sponsored | | Nov 6, 2014
Drilling deeper: On the ground insights from the Marcellus Shale region
The Marcellus Shale region is expansive, stretching from upstate New York through Pennsylvania to West Virginia. It’s an exciting time to live and work in the area. SPONSORED CONTENT
| Nov 5, 2014
AEC firms leverage custom scripts to bridge the ‘BIM language gap'
Without a common language linking BIM/VDC software platforms, firms seek out interoperability solutions to assist with the data transfer between design tools.
| Nov 5, 2014
Survey: More than 75% of workload takes place without face-to-face interactions
With the rise of technology, much of the workday—even the most productive morning hours—is spent corresponding via email or conference call, according to a recent survey of corporate workers by Mancini•Duffy.
| Nov 5, 2014
The architects behind George Lucas' planned Chicago museum unveil 'futuristic pyramid'
Preliminary designs for the $300 million George Lucas Museum of Narrative Art have been unveiled, and it looks like a futuristic, curvy pyramid.