This massive home is a landmark in the town of Princeton, Texas, located about 25 miles northeast of Dallas. With 15,600 sq. ft. of indoor space on six levels and an octagonal tower rising more than 70 feet above the footers, it is truly a milestone project.

The owner, who also served as general contractor, designed the home for durability and efficiency, while maintaining a high level of luxury.

“The home is a unique and completely custom design, done in large part by the home owner,” says Cameron Ware, who did the ICF install. “This project presented several unique challenges presented by the enormity of the project, the geometry of the home, and the heavy loads accumulated by the concrete floors.”

In total, the home used more than 16,000 sq. ft. of Nudura ICF forms—2,000 as interior walls—and an additional 10,000 sq. ft. of Insuldeck EPS floor decking. The arched arcade surrounding most of the first floor was cast-in-place with removable forms.

It supports approximately 2,000 sq. ft. of outdoor patio formed with Insul-deck. A clever thermal break, designed by the homeowner, isolates all external concrete decking from the interior concrete floors.

Each segment of the U-shaped home extends approximately 100 feet, long enough to cause concerns about floor deck shrinkage. Since an expansion or movement joint was undesirable, special consideration had to be given to floor cracking in the reentrant corners as well as ensuring that deck shrinkage did not cause excess eccentricity of the walls.

In total, the home used slightly more than 1,000 yards of concrete.

The home includes six floor elevations, all concrete: Sump room, storm shelter/safe room, first (ground) floor, second floor, attic floor and tower levels. Calculating load paths for the tremendous weight of the floors and interior ICF walls was a major engineering feat, especially since the floor plan required that some of the second floor columns and ICF walls be offset from those below. Jerry Coombs, the engineer, used transfer beams and cantilevers within the floor deck to collect the floor loads and carry them to the foundation. These beams varied in size from 36”x20” to 24”x17” and all were poured monolithically with the Insul-deck wall system.

Because of poor soil conditions on site (expansive clay), the foundation sits on 98 concrete piers each extending 25 feet into the soil.

Radius floors and landings in the tower were poured monolithically with the walls. All arches in windows and doors were built out of ICF and poured.

The observation deck is the highest point of the building, created with ICF fully around its perimeter, and supported at the attic level. Since a portion of the walls were supported on the perimeter wall of the house, and the other on the Insuldeck, the engineer also had to resolve concerns about differential deflection.

With this degree of complexity, it’s little wonder that it was visited regularly by engineers, architects, and homeowners interested in ICF. The builder discussed the project in detail in an on-line ICF forum which received more than 50,000 views.

The interior is well appointed. A broad spiral staircase connects the various levels, beginning near the basement safe room and extending past a 10-foot-diameter stained glass dome that’s well over 100 years old, to the octagonal observation tower that stands nearly 50 feet above the rolling hills that surround it.

The finished home is remarkably efficient. It utilizes a geothermal heating/cooling, which takes advantage of a lake on the property in lieu of the typical well system. The average heating/cooling cost is an amazing $90 per month for more than 10,000 sq. ft. of conditioned space. Ware comments, “These are extraordinary numbers for a home this size in the Texas heat.”