Solid As A Rock

When it comes to John and Pat DeGroot’s commanding architectural masterpiece located on a quiet street in the heart of District 66, it’s more about what lies beneath than what visitors and passersby can see on the surface. That’s because buried underneath the entire home lie some one million pounds of granite.

That amount translates to roughly 490 tons. The granite, quarried in Missouri and transported on flatbeds for the DeGroots’ dream home, comprises a heating storage system designed to control the residence’s ambient temperature.

Devising novel ways to store energy is an endeavor that has interested John since the early 1970s, when an oil embargo prompted fuel rationing. “We were going through quite an energy crisis,” he recounted. “It made people realize that we should be looking at alternatives and not be so dependent on just one way of meeting our energy needs.”

It would take several decades until the DeGroots, who will celebrate their 60th wedding anniversary in May, found the perfect alternative. In 2003, they began working with architect Eddy Santamaria, now of Contrivium Design + Urbanism, to construct a home that would meet both their aesthetic and energy demands. 

Above all, John wanted to be intentional about how to meet the home’s energy needs. “It was a challenge to be more efficient users of energy. We looked at different possibilities,” he said, noting that at the time solar panels were cost-prohibitive and less energy-efficient than they are today. Still, the building site boasted optimal southern exposure, making it ideal for the kind of alternative that John, whom Pat calls “the visionary” in the marriage, envisioned. 

 After careful consideration, the couple settled on using granite as the perfect vehicle. “Different materials capture the benefit of the sun’s energy and work as different storage mediums,” John explained. “The nature of granite is that it has a very high value in terms of being able to store energy. You want a combination of hardness, something that does not break down over time or give off dust, and something you can use in various sizes. You need to create pathways for air to circulate.”

This means using an enormous volume of rock that includes larger slabs, which form the conductive arteries through which air passes, and smaller pieces, which are more effective at storing energy.

The DeGroots enlisted SL Jensen Construction as their contractor, and the company created a concrete-lined pit for the granite, which the company also had to power wash before placing it, an arduous process that necessitated using a crane.

“He was the contractor who was willing to do this,” Pat remembered. “Some of them shied away from this—and the neighbors all thought we were building an indoor swimming pool. Everyone thought that!”

As for the architecture itself, Pat had very specific ideas in mind. “I kept saying to Eddy, ‘I love Georgian architecture, however, I love curves, and I love the movement of the buildings,’” she shared. “‘The regular English Georgian is very stiff. It’s like a salt box. But I still love Georgian. I’m still attracted to it, but I loved something a little bit softer.’ He said, ‘Oh! I’ve got it!’ And he started telling us about this Italian architect [Andrea Palladio, who designed villas, palaces, and churches during the 16th century], and we went from there.”

Those curves also served a purpose. They conceal a labyrinthine ductwork system and allow air to circulate more easily.

“The trick is to be able to hide ducts,” John explained. “You don’t want to sacrifice the things you want to have in a residence just to be able to get the benefits of the solar design.”

The DeGroots finally took up residence in 2005, and over the years, they’ve added seven geothermal wells to augment the granite, making heating and cooling independent of exterior sources.

An unexpected but luxurious benefit?

“We never run out of hot water,” Pat sighed with a smile.