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Case Studies  > Concrete "Envelope" Sets Alliant Energy's PowerHouse Example Home Apart From Others
Patent-pending Technology Reduces Heat Loss in Winter and Heat Gain in Summer
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Alliant Energy, headquartered in Madison, Wis., is an energy holding company serving more than three million customers worldwide. Alliant Energy's PowerHouse is an award-winning educational television program designed to help encourage viewers to improve the energy efficiency, safety and comfort of their homes.

The PowerHouse Home was the success of a team of companies, many of them with Iowa ties, working together to help teach homeowners about the value of energy efficiency. In doing so, many different concrete products and technologies were used and aided in the project’s success.

Insulated concrete forms (ICF)

The foundation walls of the PowerHouse Home are made of TF Insulated Concrete Forms (panels made of expanded polystyrene).

The EPS panels were fitted together using steel I-beams and C-shaped channels. Installers reinforced the forms with steel rebar and then filled the area between the panels with concrete. Electrical and plumbing lines were concealed within carved channels cut into the EPS panels.

The ICF system in this home has an insulating value of R-32.5 and the ability to eliminate air infiltration. This translates into very low heating and cooling costs for the PowerHouse Home.

Wall panels
The PowerHouse Home framing includes rigid expanded polystyrene panels, as part of the patent-pending ZeroNet envelope system.

These panels were custom-cut using computer-aided design with an embedded compressed wood frame. A fiberglass-reinforced concrete was then applied to the interior and exterior of the panels, creating a super-strong, super-efficient wall structure with a nominal R-value of 40 in the walls and a nominal R-value of 60 in the roof. EPS underslab insulation with an R-value of 10 was also used on the PowerHouse Home.

Fiber-reinforced cement was applied to the home’s expanded polystyrene wall and roof structure. Maher Products also created the columns in front of the home and the decorative trim around the outside windows. Nippon Electric Glass supplied the glass fibers which were used to reinforce the concrete coating applied to the interior and exterior sides of the expanded polystyrene panels which form the walls and roof of the PowerHouse Home.The fiberglass-reinforced concrete formed a super-strong, super-efficient wall and roof structure.

Because the roof of the PowerHouse Home is made of concrete, it was not possible to nail traditional asphalt shingles to it. Instead the home features flat, concrete tiles. The tiles are virtually maintenance free, won’t fade or break down and will even stand up to hail. The polyfoam adhesive used to adhere the tiles to the roof was supplied by Polyfoam Products, Inc. Because of the combination of roof panels, the polyfoam adhesive and the tiles, heat that is absorbed through the tile is prevented from moving into the house.
Project Team:
Owner: Alliant Energy for its PowerHouse educational program
Architect: VGI Design
Energy Efficient Patent-pending Technology: ZeroNet Envelope, LLC
General Contractor: Schroeder/Leverington, Inc.
Contractor: Bos Construction
ICF Manufacturer: Heartland EPS
Roofing Manufacturer: Vande Hey Raleigh, Inc.
Fiber-reinforced Cement Manufacturer: Maher Products