When a poured wall contractor finishes a basement this huge and remarkably complex, he can only do one thing: submit it to the Concrete Foundations Association’s Basement of the Year competition.

This year’s solid competition made for tough judging by fellow contractors. But the 50,000-square-foot basement of the Pritt residence stood above all the rest in more ways than one. The winning basement belongs to the most expensive home currently on the market in the U.S., listed at $75 million. Built by Ekedal Masonry and Concrete, Inc., Newport Beach, California, this two story basement near the ocean in Corona Del Mar, California, caught 50 percent of the votes this year as the “most visually intimidating entry.”

The basement used 3,879 yards of concrete and 215 tons of steel in the walls. The job racked up 780 lineal feet of wall, with heights ranging from four feet to 45 feet. Wall thicknesses range from 8 inches to 36 inches.

Ekedal used caissons in rock to overcome geological conditions and lengthy shoring specifications. The company kept a full time CAD operator on site in order to master the angles, radiuses and the intricate tops. Adding more complexity, a tunnel leads from the house to the ocean. In addition, the project includes a waterside, pool and multiple block-outs.

“Even though projects like this are common to our company, we had to be aware that this

home is surrounded by $20 million homes and was very high profile,” says Ryan Ekedal, vice president, Ekedal Masonry and Concrete. “We had to take extra precautions on everything from monitoring ground vibrations and shoring walls to overall liability concerns. We knew that because this job was receiving major exposure we were under the microscope and everyone had to give an added 100 percent to the work and concentration they were already applying to the project.”

The second place winner in the 5,000-square-foot, single family category is Custom Concrete, Westfield, Indiana, with a 15,500-square-foot basement in Martinsville, Indiana. Wall heights range from 3 to 15 feet with a total of 20 angled corners. The footings measure 2 and 3 feet wide by 12 inches deep with two rows of No. 6 continuous rebar. Even the lot was a challenge. Sitting on the top of a steep hill, it took 2,000 tons of gravel for the atrium.

The foundation measures 953 linear feet and includes 270 cubic yards of concrete for the walls, 100 cubic yards of concrete for footings that contain 2,000 linear feet of rebar. The job included a reinforced safe room and an aquatic center within the basement area.

“This was one of the most challenging jobs our firm has tackled,” says Brian Kincaid, field manager, Custom Concrete. “The different size and heights of the walls, complexity of the footings and job access made this a very unique project.”

The third place finisher is the 16,000-square-foot basement of the Prescott Residence in West Bend, Wisconsin, built by Coello & Associates, Inc., Waukesha, Wisconsin. The foundation wall is 10 feet high and includes two faces of steel rebar. Coello used more than 9,000 lineal feet of steel rebar in the wall. One challenge in forming the wall was a double ellipse on the rear of the house. Squaring up this portion of the foundation was extremely complex because of its odd shape, 10-foot height and the location of two ellipses back to back.

To cope with the poor soil conditions Coello built the footings 18-inches thick ranging from 20 to 42 inches wide, containing almost 700 yards of slurry mix. The reinforcement in the footings includes rebar in both directions and L-shaped steel bars.

Winner in the Commercial/Multi-Family category is a 10,700-square-foot basement for the Briar Creek Golf Club, Johns Island, South Carolina, constructed by Sunburst Builders, LLC, of Charleston, South Carolina. The project has double matted No. 6 rebar encased in No. 4 stirrups, placed 24 feet on center. The walls are 16 inches wide with two octagonal decks and arches between columns. The golf club is located in a storm surge zone, dictating 4-foot-deep footings, which sit below the water table. Due to the footing depth and heavy rainfall, the project required constant de-watering. Coello used aluminum forms, wood forms and Styrofoam shapes to form the 24-inch by 16-inch columns connected by arches.

The 348 linear foot foundation contains 188 cubic yards of concrete and 8,460 pounds of steel in the walls and 252 cubic yards of concrete and 12,820 pounds of steel for footings.

The winner in the single family 2–5,000-square-foot category is another project built by Coello & Associates, the 4,500-square-foot Koepke residence, Dundee, Wisconsin. Featured on the television show Extreme Makeover: Home Edition, this home has a full 8-foot-deep basement, unlike most homes featured on the program. To meet the speed requirements—a finished foundation in 12 hours or fewer—Coello used a fast setting concrete mix design to reach 3,000 psi after just four hours and 8,000 psi at 28 days. Coello beat the clock, finishing the job in 10.5 hours, donating all the labor and equipment for the project.