Last September, builder Mark Johnson was looking for an innovative way to generate customer interest for a spec home he was planning in Wilmington, N.C.

Nine months later—after a crash course in high-performance building techniques—Johnson not only had produced an innovative home, but an award-winning LEED-H Platinum dwelling constructed with insulated concrete forms (ICFs) that will save $2,200 on utility bills and more than 100,000 gallons of water a year.

“We weren’t initially planning to build a green home,” says his brother, Kevin Johnson, director of business development for Mark Johnson Custom Homes. “But we knew it needed to be something a bit different, because the market was starting to slide.”

The brothers’ leap into green building began at a concrete symposium in Charlotte, N.C., where they learned of the environmental and storm-resistant benefits of concrete-built homes. They felt that building with ICFs, which boast a wind rating of up to 250 mph, would be just the thing to get buyers in their coastal city to take notice.

Soon afterward, they attended a one-day training session with ICF manufacturer Logix  and selected a consultant to walk them through the project’s major concrete-pouring phases.

Building with concrete forms for the first time was exciting but nerve-wracking, Kevin Johnson says. “The day we drove up to our jobsite and they were pouring concrete it was very exciting,” he says. “But, if you make a mistake in traditional framing, you can re-do it; you don’t have that option with a concrete wall full of rebar. It requires detailed planning to make sure you’re doing it right.”

The Logix system, which features many recycled materials, including the foam panels and the webs that hold the rebar, delivered 26 LEED points. The home’s exterior walls were built 1 foot thick with 6 inches of concrete sandwiched by 2 3/4 inches of Logix foam panels on each side, providing R-50 insulation, Johnson says.    

For all the futuristic-looking building materials that went into it, the finished product is a beautiful, traditional four-bedroom home, which is currently on the market for $599,000. “The only thing different about it that people notice is that is has very deep windowsills,” he says.


Meeting LEED requirements for the first time also was a learning experience for everyone involved, including suppliers and subs, Johnson says.

“We needed to explain the process to them, and why we were doing it,” he says. “We told them, ‘There’s a lot of inventory out there right now, we need to do something different to get buyers’ attention.’”

The Johnsons and their trade partners learned about certified-green building side by side on the jobsite with a few mistakes along the way.

“Suppliers were quoting me LEED points toward the Platinum rating that were inaccurate,” Johnson says. “They were confused between LEED for Homes and the commercial version of LEED and were quoting me six to seven points for my cabinets when that was the number for a commercial project, not for residential, which is two points.”

Still, Johnson found the USGBC-administered program to be flexible and when he made a case that the home’s TED energy-monitoring system should be eligible for LEED points, USGBC officials agreed and granted one point in the Innovation and Design section of the program.

“The USGBC recognizes that there is more than one way to do things, and you can make a case if it’s not on the checklist,” he says. “We made that argument because at the end of the day, true conservation is about changing consumer behavior, and that’s what an energy-monitoring system does.”

It worked out well that the company’s first third-party-certified home was built on spec, because it took longer and cost more than most other projects, he says. Johnson estimates that building the home to LEED Platinum specs added about 9% to the cost.

“It’s a tough process up front, we never could have done this on a homeowner’s dime,” he says. “The next one will be that much easier.”


Now that the builders are familiar with both ICF construction and the LEED process, Johnson says future sustainable homes they build should cost less and take less time. They are committed to having any future sustainable projects certified.

“It’s the only way to really know if the builder has done what he’s said he’s going to do,” Johnson says. “If a builder puts up a house with one compact fluorescent light bulb is that really a green home?”


Also helping to rack up LEED points is the 2,750-square-foot home’s miserly use of water. The Bosch dishwasher uses less than 6 gallons on a standard cycle, and low-flow bathroom fixtures and dual-flush toilets keep water use to a minimum.


Outside, a buried 1,800-gallon rainwater collection tank collects 98% of roof runoff for watering the yard. A Netafim underground drip irrigation system saves as much as 1,600 gallons on each watering compared to a traditional sprinkler system on a same-size lot. Rain sensors guard against overwatering.


A Rinnai tankless water heater, Energy Star appliances, energy-efficient windows and doors, and a 17-SEER Trane HVAC system with an energy recovery ventilator round out the high-performance features. The estimated cost of electricity and gas to operate the house is $1,763, a projected savings of $2,276 a year.

The cedar shake roof was an aesthetic requirement for the neighborhood, Johnson says, adding that local covenants prohibited the use of solar panels except in certain situations.

“There’s really nothing groundbreaking in the home--there’s no solar, no geothermal,” he points out. “We realized we’re just scraping the top of the iceberg; there’s so much more we can do next time.”


Now that Johnson has built the first LEED-Platinum dwelling in Wilmington, he has an equally difficult challenge ahead of him: marketing it. He has prepared a slide presentation about green home building for local real estate agents, many of whom are not familiar with the benefits of a certified home.

“I have been meeting with local real estate agencies explaining the subjectivity of green building, letting them know that there is no one right way to do it,” he says. “I don’t really call it a ‘green’ home anymore, because people don’t know what that means. I phrase it as ‘energy efficient’ or ‘water conserving.’”

Johnson says when he gives tours he always brings along a concrete form to show how the technology works. “We’re fighting against short sales and foreclosures and other homes on the market that are bigger than this one selling for the same or less money,” he says. “We have to make the case to show the life-cycle costs are less expensive in this home.”

Jennifer Goodman is Senior Web Editor for EcoHome.