Focus on Energy Efficiency

It might be materials that build the world, but today the design and construction industry is turning its gaze upon energy efficiency, the measure by which all new structures are now appraised as part of the evolving sustainability movement. If the greenest materials around don’t result in a low-energy structure, why build with them?

That’s where concrete comes in: “There is no other more energy-efficient building material known to man,” explains Brian McCarthy, president of the Portland Cement Association (PCA). As a baseline, “Buildings with concrete external walls use up to 40 percent less energy than wood frame buildings,” he says.

According to market research recently conducted by PCA, 77 percent of surveyed architects, designers, engineers and other design professionals say they chose concrete as their sustainable material for recent projects. In fact, energy efficiency was perceived as the most important attribute when selecting a building material, followed by durability and aesthetics.

This focus on energy use is part of a bigger effort by the building industry to step back and view sustainability as a big picture issue. “In a very practical sense, sustainable development means looking at the total life cycle,” says McCarthy. This necessitates conducting more life-cycle assessments (LCAs) for materials and processes. “We have to expand our definition — it goes beyond cement, into concrete,” he says.

The industry is making strides in reducing its energy use and emissions. “We still have to make changes in the manufacturing process, and the industry has committed to voluntary targets,” says McCarthy, “but true sustainable development does not begin and end with one component.”

New Technologies and Policies

It’s not just the design community’s focus on energy efficiency that’s driving change in the construction industry; new legislation — from the federal level down to the smallest municipalities — is demanding more sustainability when it comes to repairing and building new infrastructure. In Chicago, for example, an ordinance enacted in January 2008 creates more stringent requirements for stormwater management, spurring the use of pervious concrete pavement throughout the city in alleys, parkways, roadways and parking lots.

Ready mixed concrete companies are innovating, too, creating new products to solve fresh challenges posed by the sustainable movement. In Colorado, Recycled Materials Company created Biota from recycled concrete runways at the former Stapleton Airport in Denver; the uniformly graded concrete rubble is used as a protective layer to keep rodents from burrowing into entombed environmentally sensitive material on neighboring land.

And where concrete itself can’t be improved upon, firms like Dukane Precast in Naperville, Ill., are finding other ways to go greener, like using bio-based foam — that partially substitutes castor or soybean oil for petroleum products — in its precast double wall system.

Cement’s Forecast

Given the snowballing sustainability movement, the cement industry is currently engaged in a $6 billion capacity expansion to accommodate the growing need for concrete. Ed Sullivan, chief economist for PCA, says that in the short term, some of this expansion will be postponed because of the current economy.

But he stresses that the cement industry is ready. The next couple years will be challenging, and then “strong growth rates in cement consumption are anticipated beyond 2010,” Sullivan says in his most recent forecast.

“All that expansion is being built for a reason…by 2030 we’re still looking at a 180 million ton market,” says Sullivan. Demand will be driven by a large expected U.S. population increase: “Sixty-three million more people will be living in the United States in 2030 and they will need homes, schools, hospitals and roads. This construction will boost demand for cement to record levels.”

In the residential sector alone, expected growth (to more than triple today’s numbers) in the use of insulating concrete forms (ICFs) to build energy-efficient homes will have a major impact: “If these green conditions materialize residential concrete construction will add roughly eight million metric tons to the cement intensities in 2030,” Sullivan says.

Sidebar: Small Town Takes Concrete to the Extreme

Photo courtesy of Logix ICF

In Greensburg, Kan., concrete is literally the building block on which the town stands. Or will stand, that is — on May 4, 2007, a massive tornado ripped through the small town, devastating nearly everything and leaving a lone concrete silo standing in its wake.

It took only a few days for Form Systems, a nearby insulating concrete form (ICF) manufacturer, to move in and help kick off the rebuilding of Greensburg, starting with the home of then-Mayor Lonnie McCullom, using its Logix brand of ICF.

little more than a year later, the town is fully committed to building green all the way, with the help of companies around the nation and under the watchful eye of the press. (Leonardo DiCaprio has executive-produced a TV series, “Greensburg,” documenting the town’s progress for Discovery Networks’ new station Planet Green.)

Almost 25 structures in greensburg are currently being rebuilt with Logix ICFs, and the next two years should see many more, says Scott Rudd, operations manager for Form Systems.

Daniel Wallach, director of Greensburg Green Town — a nonprofit helping manage the town’s reconstruction — says formidable concrete structures are just what the townspeople need right now. “There is a lot of common sense to it,” he says. “When you’ve lost your home to a tornado, concrete sounds pretty good.” And as a bonus, says Rudd, those new ICF homeowners will cut their HVAC systems’ initial costs by a third and easily enjoy a 50 percent savings on energy bills.