HIGHLANDVILLE, Mo. — Steven Huff of Virginia is building a second home in the Ozark Mountains. At 72,000 square feet, it will be one of the largest residences in the United States, with 13 bedrooms and 14 bathrooms.
Huff’s house will be bigger than William Randolph Hearst’s castle in San Simeon, Calif., Bill Gates’ mansion in Medina, Wash., and the White House.
It’s more than just a big house, Huff said. When finished in 2013, it will be a showplace, an example of how large commercial structures can be built using a concrete forming system that he developed. Huff said the house will be energy efficient and able to withstand an EF5 tornado.
He calls the building Pensmore, from the French root word for “think” and the British root word for “more,” translating to “a more thoughtful way to build.” It is a combination of French and British architectural styles, resembling a French chateau, on a hilltop between Branson and Springfield, Mo.
While building a concrete barn at his home in Virginia three years ago, Huff became interested in the ancient construction material.
“My background, I’m more of the eccentric geek,” he said.
Huff had sold his software company, Overwatch Systems, but was still doing some consulting for the company. With two physics degrees, Huff saw ways he could improve on the system that was being used to form the concrete walls of his barn.
The concrete walls are built using interlocking blocks made of polystyrene foam or other materials, often stacked together vertically with concrete poured into the hollow part. Reinforced steel bars are added to make the walls stronger.
But Huff saw consistent problems with the traditional method of concrete wall building.
For one thing, the insulation was too thin, contributing to frequent “blowouts”that occur when the poured concrete then breaks the wall of the insulation. Huff fixed that by using polystyrene insulation that is from 4- to 8-inches thick on the outside of the wall, which also helps with energy conservation and keeps the concrete from getting wet. On the inside of the concrete form, Huff uses a three-quarter-inch layer of rigid insulation to hold the concrete in place.
Also, Huff incorporated a rigid rail system to keep the blocks aligned and the walls straight.
“Pensmore is, architecturally speaking, the perfect test site for the product because it will offer various heights of walls from 4-feet to 32-feet tall,” according to a document from Eva Van Brunt of Los Angeles, Pensmore’s spokesman. “The building has multiple different-angled corners, arched windows and even different styles of walls.”
The walls, which have already been constructed, look fine, Huff said.
Huff’s barn was being built with a vertical concrete system from TF Concrete Forming Systems Inc. of Green Bay, Wis. Since TF Concrete hadpatents on part of the process, Huff decided to invest in the company so he could help improve on its system.
He worked with Gerald Spude at TF Concrete to come up with the forming system he’s using at Pensmore. It’s called TransForm. Huff became majority owner of TF Concrete and chairman of the company’s board.
Huff decided to make the mansion a laboratory.
“I was planning the house anyway, so I decided to design it around the new system,” he said. “I wanted to prove that the system would apply on a commercial scale. It’s easy to build a small home out of it.”
Huff said local building regulations made it easier to construct Pensmore in Missouri than Virginia.
It costs 5 percent to 10 percent more to build with concrete, but the structures will last “forever” and the energy savings will offset the construction cost, Huff said.
Huff began construction on the Pensmore project two years ago. First, Huff had to build a road to the site and a bridge over Woods Fork Creek.
After a year, construction began on the house, but by then rumors were flying. Bloggers theorized that there was a bunker underground already, but there’s not, Huff said. He had kept the project secret for as long as possible because of patent applications for the concrete forming system.
“They filed a building permit in 2008,” said Lena Cheney, code enforcement officer for the Christian County,Mo., Planning and Zoning Department.
Originally from Brunswick, Mo., Huff wanted to build a second home in the Ozarks, and he wanted it to be able to withstand tornadoes. Huff bought the 550-acre site four years ago.
Two smaller structures have been built in Virginia using TransForm: an addition to Huff’s house and a fellowship hall for Bethel Orthodox Presbyterian Church in Leesburg. Each was about 8,000 square feet.
Pensmore will harvest solar heat energy during the dayand store it within the steel-reinforced concrete shell of the house, Huff said. Inside the walls will be plastic tubes full of antifreeze that will transmit radiant heat.
Pensmore will be able to store approximately 65 million British thermal units of energy while the sun shines and slowly release that heat into the interior at night and on cloudy days, Huff said.
“It’ll give up its heat to the inside of the house,” he said.
The reverse effect can be used in the summer by running cool liquid through the tubes.
Arkansas, Pages 17 on 10/23/2011