A 72,000-square-foot chateau being built on 550 acres in the Missouri Ozarks is doubling as a laboratory for a concrete forming system whose manufacturer and the home’s owner believe could have broader applications for disaster-resistant and energy-efficient construction.
The concrete colossus, called Pensmore, is located in Highlandsville, Mo., between Branson and Springfield and near Joplin, which last May got leveled by an E-5 tornado. The house, which has received extensive press coverage, is the brainchild of 60-year-old Steven Huff, who made his fortune selling software for medical, defense, and intelligence applications.
Huff wants the home—where his family will live once it’s completed in 2013—to be nothing less than a model demonstrating the value of long-term durability and life-cycle cost effectiveness. He is collaborating with a number of green construction companies, one of which is TF Concrete Forming Systems in Green Bay, Wis., a 17-year-old manufacturer that Huff acquired and serves as chairman.
For this project, TF developed a form system called TransForm, a hybrid between insulated concrete forms (ICF) and removable forming systems. What makes TransForm unique, explains TF’s CEO Kirk Brown, is that it fully insulates the outside of the concrete wall with a thick layer of foam while coating the inside of the wall with only a ¾-inch layer. “This exposes the thermal mass of the concrete to the inside of the structure while isolating it from the outside temperature extremes,” Brown says.
He adds that the thermal mass of the concrete acts as an “energy storage battery” resulting in “extreme reductions in energy consumption.” And a water/antifreeze mix running through tubes embedded in the concrete allows for “active core management using geothermal and solar for primary heating and air conditioning.”
The house has internal walls over 30 feet tall held in place by plastic studs and external walls over 80 feet tall held up by steel frames. Those heights, says Brown, aren’t achievable with block-based ICF systems. Helix wire fibers, provided by a company called PolyTorx, fortify the concrete mix while making the walls more pliable and resistant to earthquakes, blasts, and tornadoes.
Construction, which began in 2008, is taking a long time to complete because Huff is only employing a single crew and “has been experimenting with different things,” says Brown. He notes that the recent construction of an 8,000-square-foot church in Nevada took only two weeks to lay in the TransForm walls.
Brown is reticent about costs, but estimates payback from energy bill savings to be in the five-year range, and the annualized return on investment after 10 years at 10 percent to 15 percent.