Concrete's Energy Efficiency, Durability Lauded
BOSTON — Concrete was used as a sustainable material by more than three out of every four design professionals recently surveyed about their preference of materials for sustainable design.
According to a market research study conducted by the Portland Cement Association (PCA), 77 percent of surveyed architects, designers, engineers and other design professionals said they chose concrete as their sustainable material for recent projects. Respondents ranked concrete favorably for its energy efficiency, durability, and reduced maintenance.
"There are few, if any, construction materials that offer concrete’s wide range of sustainable and environmental benefits," said PCA President/CEO Brian McCarthy. "This survey shows the design and building community recognize that concrete can address the issues most important to their sustainable development activities."
Survey respondents ranked the level of importance of 22 attributes when selecting building materials. Energy efficiency was perceived as the most important attribute when selecting a building material with a mean rating of 4.5 out of five, followed by durability (4.4), and aesthetics (4.2).
When asked which building material they preferred to meet those attributes, concrete was the most common response for energy efficiency and durability.
"Buildings with exterior concrete walls utilize less energy to heat and cool than similarly insulated buildings with wood or steel frame walls," McCarthy said. "The superior insulation, air tightness, and mass of the walls can reduce energy for heating and cooling by up to 40 percent. Plus, smaller, more efficient heating and cooling equipment can be installed."
Concrete’s role went beyond energy efficiency however. After measuring the mean ratings of the attributes and evaluating how concrete, wood and steel were ranked against those same attributes, an index was developed to score how each material ranked, overall, as a green material. Concrete’s green factor was 4.20, wood was 4.03, followed by steel with a green factor of 3.85.
"Not only are architects and designer choosing concrete, they are spreading the word on its effectiveness. Sixty-three percent were very likely or likely to recommend using concrete for a sustainable building design, compared to 54 percent that would recommend wood and 53 percent for steel," McCarthy said. Additionally, 42 percent agree or strongly agree that predominately cement/concrete structures provided greatersustainability than other materials.
The questionnaire, conducted in early 2008, was sent to architects, designers, engineers, and environmental planners and managers. More than 500 respondents answered a blind survey, presented in an internet survey form from a third-party Web host. Respondents were asked to answer the questions based on projects they had worked on the most during the last year.