Concrete results: New house’s efficiency is a stunning surprise for builder, who predicts 75 percent decrease in utility expenses

The right idea at the right time?

John Craft, owner of Kaw Valley Home Care, stops along the stairway of one of his recently built homes at 1417 Prospect Ave. Craft believes that the home is the most energy efficient in the area, primarily because of its use of concrete walls and floors, which keep the interior at a near constant temperature.

John Craft was mad when he walked into the new East Lawrence home he was building.

He’d been gone about a week, and when he walked in from the 100 degree heat, he was greeted by a cool 78 degrees. He was upset his workers had left the air conditioner on.

Then he realized: They hadn’t.

Despite a week of triple-digit temperatures, the temperature in the home remained below 80 degrees.

“I think you may be looking at the most energy-efficient home, maybe in the state, but I’m pretty sure in the area,” said Craft, owner of Kaw Valley Home Care.

Cooling concrete

That’s not by accident. The home at 1417 Prospect Ave. is unusual. For starters, its walls are concrete – eight inches of cement sandwiching four inches of Styrofoam.

And the floors in the house – up and downstairs – are concrete. That allowed Craft to heat the home entirely with radiant heat, a system of tubes piping hot water through the concrete floors. Instead of a traditional furnace, the house is heated with a 50-gallon, high-efficiency water heater.

Craft predicts utility bills will be about 75 percent less in this home than in a traditional house, though he won’t know for a while because construction was just completed.

“I think most of the time, the utility bill will just be the minimum charge that the utility companies make you pay,” Craft said.

The key to it all, Craft said, is the concrete.

“There’s so much concrete in here that it keeps the house at a nearly constant temperature,” Craft said of the 1,500-square-foot home. “Basically, once you get the concrete at the temperature you want it, it stays that way for a long time.”

But do people really want to live in a house with so much concrete? Craft is betting some do. He built the house on speculation, meaning he built it without a buyer. He just finished the home this week and plans to put it on the market for a little less than $200,000.

With soaring energy costs, builder John Craft thinks houses like this 1,500-square-foot one at 1417 Prospect Ave. may be the wave of the future. He plans to put it on the market for a little less than 00,000.

He’s already planning on building more of the homes, and he thinks concrete housing will become more popular across the country.

“I absolutely think people will start building homes more like this because the public will start demanding it,” Craft said. “Maybe utility prices aren’t high enough now to spur it, but just wait a year or two and I bet they will be.”

Cusp of change?

But new neighborhoods of concrete homes probably won’t happen anytime soon, according to Shery Hoellwarth, a consultant with Stockton, Calif.-based ConSol. The company provides technical assistance to builders wanting to construct homes with an eye toward energy efficiency.

“It is a slow industry to change,” Hoellwarth said.

Builders prefer to do what they’re comfortable with, and they haven’t had much reason to change.

The home is heated by hot water tubes running through the floors and controlled by this high-efficiency water heater.

“Up until now, builders have been able to sell pretty much everything they’re building, so there hasn’t been anything pushing them to change,” said George James, project leader of Building America, a Department of Energy program that partners with home builders to promote energy efficiency.

But times and attitudes may be changing. James said the National Association of Home Builders has been preaching energy efficiency to its members, and there is a different breed of home buyer slowly emerging.

“A lot of the younger folks are very interested in green energy and sustainable practices,” James said. “My hope is that in 10 years the building industry is substantially different. But what’s more important than my hope is that I’m starting to see some signs of that.”

Craft is even more confident. A combination of warmer temperatures, higher utility prices and the role oil is playing in world politics has him convinced more and more people are ready for a different type of home.

“I have to say that I have a problem with us being in a war that I think is pretty much about petroleum,” Craft said. “It just seemed to me that this was a good time to build this home because with what I see in the world, I don’t think petroleum or energy prices are ever going to go down.

“I’m really excited about what we’re doing because it seems to be the right idea at the right time.”

Tips for building an efficient home

George James, of the Department of Energy, said concrete is a good way to build an energy-efficient home. But there are other ways, too. Some examples:

¢ Metal roofs. John Craft used a white metal roof that reflects the hot summer sun.

¢ Lots of southern facing windows. These allow sun during the winter to shine into the home and provide natural warmth. Craft said this is particularly useful when combined with heat-absorbing concrete floors.

¢ Window awnings or overhangs. The overhangs protect the southern-facing windows, and others, from summer sun.

¢ Thicker walls. You don’t have to use concrete to beef a home’s walls. Builders can use 2 by 6 lumber to frame walls rather than the traditional 2 by 4. This provides more room for insulation. James thinks this will be one of the more popular trends in building because contractors are discovering they can safely use fewer pieces of the wider lumber to support the home, thus saving on lumber bills.

¢ Tighter duct work. Shery Hoellwarth, a consultant with Stockton, Calif.-based ConSol, said making sure duct work is tightly sealed is one of the easiest improvements a builder can make.

“Most people have no idea how much air conditioning is going up into the attic where they don’t care whether it is cool,” said Hoellwarth, whose company helps builders construct energy-efficient homes.

¢ Better quality windows, doors and appliances. The federal governments sponsors a Web site – – designed to help consumers select energy-efficient appliances and materials.

$avings within sight

Through the Department of Energy program he oversees, George James has watched Habitat for Humanity build homes that cost their owners only 23 cents per day in utility bills.

But each of the homes was equipped with $25,000 worth of special solar panel cells, a financially unfeasible alternative for most people. Eventually, though, the price of solar panels – like all technology – likely will come down, and James’ Building America project is researching other energy-saving possibilities all the time.

“The goal is that by 2015 we’ll have solid research done that shows people how to design a house to save 40 to 60 percent of its energy without adding much cost to construction,” James said.

Lawrence builder John Craft, who this week completed a new concrete home, also is optimistic. He estimated the 1,500-square-foot home cost him 20 percent more to build than if he had used traditional methods. But once he becomes more familiar with the building process, he expects the cost difference to drop to about 10 percent.

He thinks that price difference will be worth it for owners wanting a more efficient and durable home.

“This concrete, because it is stained, never has to be painted, and you never have to worry about termites,” Craft said.

Concrete may not be right for everyone. For example, Craft uses concrete on the interior of the house, too, meaning walls don’t have that traditional drywall look. Also, since the home uses concrete flooring with radiant heat, wall-to-wall carpet may not be the most practical.