“You got to plan for it,” MacNeel says. “You can't automatically think that you are going to be able to run down to the Home Depot to get some high-strength steel.”

One engineer not involved with the study says he prefers use a lesser-known alternative, specifying midgrade 75-ksi rebar.

“It's been around for years, and there is no complex math involved,” says Cliff Schwinger, vice president of Harman Group Inc.

Over the past 10 years, the King of Prussia, Pa.-based firm has been designing with 75-ksi rebar, which saves up to 20% in weight.

“There is only a 5% cost premium,” Schwinger adds.

Most mills can produce the mid-strength rebar; however, they typically require a minimum order of 100 tons for each bar size. In addition, sizes below No. 9 are usually not offered in 75-ksi strengths.

“You don't just make all the steel on the job grade 75,” says Schwinger, who is hopeful that its use will increase.

“I think eventually grade 75 is going to replace grade 60.”