By the warmth of the sun: Montrose man building first-of-its-kind “green” home

Correction Appended

MONTROSE — On a side street off Main, Montrose-native Sven Krebs is deep in an experiment involving sunlight, recycled materials and loads of concrete.

A construction worker by trade, Krebs has been more of a scientist lately. He’s piecing together “green” ideas in the building of his home — a 1,100-square-foot, two-bedroom, two-bath abode— on an unlikely plot in the middle of town.

“It’s an experimental house,” he said. “I tried all the different things I wanted to try out.”

Krebs, working with Lynn Baird of Wildcat Construction, hopes the project will be finished by Thanksgiving. He estimates it costing roughly $100 per square foot.

The biggest experimental leap in the project is the use of a relatively new thermal wall system (introduced a few years ago) using forms from Missouri-based company Western Forms.

“It’s the reverse of the foam block,” Krebs said. “It’s really thermally efficient ... It improves the function of the insulation by encasing it in the concrete.”

Four-inch foam boards are suspended between aluminum forms on either side. These forms create pockets into which concrete is poured. The forms are removed the next day leaving just the concrete walls.

These walls provide a more continuous layer of insulation, rather than being separated with structural studs, which draws heat in and out of homes. In the end, the masonry material will save Krebs money on finishing products. Except for a bit of earth-colored stain, he plans to leave the walls bare, giving them an industrial, modern look.

Krebs’ home will probably be the first in the city to use the method; poured-in-place basement walls and tilt-up panels, also using concrete, have been previously used, said Montrose chief building official Frank Mesaric. The most challenging thing about building the home from this method is ensuring vent locations are correct, he said.

Locating the right equipment for the project also proved difficult. Forms used in this particular system weren’t readily available for use. Krebs lucked out and found a contractor in Rifle to rent them from. Baird said the wall system’s method is time consuming but relatively easy to do.

Although passive solar wasn’t perfectly suited for Krebs’ parcel, it did drive the home’s design.

A long and skinny, south-facing building is ideal for passive solar but wasn’t possible on the site. Krebs made best use of the space and concept with an L-shaped home that makes room for windows and solar gain.

“It’s gonna work very well for him (Krebs) because he’s thought long and hard about sun angles,” said Mesaric.

Structural Insulated Panels or SIPs, which would add to the energy efficiency of the home, are being used for the roof.

“Everyone is starting to pay attention to energy costs,” said Krebs. “I designed this house to be used with as little energy as possible. This new wall system was really compatible with passive solar and the two together are going to create a house that will both heat and cool without much energy at all.”

Passive solar is a home design method based on a fundamental law: heat moves from warmer materials to cooler ones until there is no longer a temperature difference between the two, the U.S. Department of Energy noted.

Using heat-storing and heat-moving mechanisms, homeowners can make use of solar heat to keep the temperature of a building relatively constant, improving comfort and energy efficiency.

Sunlight comes through windows and is absorbed and stored by masonry floors and/ or walls. At night, as the room cools, the heat stored in the thermal mass (in this case concrete) convects (heat circulates) and radiates into the room.

“We would certainly encourage people to try to use more solar, especially passive solar and we try not to discourage that,” said Mesaric. The city hasn’t had an increase in people using passive solar but has seen more conversions of patios into sun rooms.

Blaine Nye is concrete home product manager at Western Forms. He said more people are using above-grade-cast-in-place-concrete-wall systems because of their energy efficiency and disaster resistance, which lowers insurance costs, especially in places like Florida.

When asked about the product’s drawbacks, Nye said, “The challenge is just the fact that it’s new,” which requires the education of contractors involved in the project.

Costs are comparable to conventional home building materials but depend on a number of factors, such as site location and needs, Nye said. There are also the added benefits of insurance and energy cost savings.

Another notable perk is the system’s green building method.

“We’re not using trees. This is a sustainable material. They’re (walls) going to be around for generations,” he said. If the concrete walls were torn down, they could be crushed and recycled back into aggregate for use in new concrete.

As Krebs began working on his home, he also constructed a piecemeal workshop made of salvaged wood from the adobe home that used to be on the property. The metal roof sheltering the workshop came from nearby Recla Metals.

Krebs said he wants others to know about his project because energy issues are changing perspectives on living and consuming.

Contact Lisa Huynh via email at lisah@montrosepress.com

This article has been revised to reflect the following correction:

In Wednesday's article about green home design, SIPs panels are Structural Insulated Panels, not Solar Insulated Panels as incorrectly stated in the story. The Daily Press regrets the error.