Plastic Building Products Make New Chateau More Energy-Efficient

A chateau currently under construction in Highlandville, Mo., will be one of the largest homes in the United States—72,000 square feet, even larger than the White House—when completed in 2013.

But what really makes the Pensmore chateau unique is its design. Pensmore’s owner set out to design an exceptionally energy-efficient building that is durable enough to last hundreds of years—a prototype for more sustainable future buildings. To accomplish these goals, Pensmore’s designers are making use of two innovative technologies made possible by plastics: insulating concrete forms (ICF) and cross-linked polyethylene (PEX) pipes.

ICF is a system for building walls with concrete and plastic foam. At Pensmore, concrete is cured between two layers of polystyrene plastic foam—and these layers remain in place as part of the wall system. The plastic foam provides excellent insulation, helping keep the house cooler in summer and warmer in winter and reducing the amount of energy required. And according to Pensmore’s designers, the ICF system will make the building up to 10 times stronger than a traditional wood-framed structure. The plastic also is less susceptible to damage from moisture or insects than wood, making it an excellent choice for a long-lasting, weather-resistant structure.

The designers of Pensmore are also relying on another innovative plastic building product to improve energy-efficiency: PEX pipes. Made with extra-strong polyethylene plastic, PEX pipes are flexible and resistant to temperature extremes. The pipes are installed throughout the building’s structure, and then antifreeze is circulated through them, extracting solar energy from panels on the roof during the winter and geothermal energy from under the ground during the summer. This allows a relatively stable temperature to be maintained year-round throughout the house with minimal energy costs. Because the PEX plastic is resistant to biological attack from soil or weather, the plastic “HVAC” system can perform effectively for many years without needing to be replaced.