A married couple in Wisconsin becomes the first to participate in a sustainable-homebuilding initiative sponsored by regional utility WPPI Energy

Tom and Verona Chambers bought an acre of land on west-central Wisconsin’s Black River. It is, by any standard, a scenic spot, and the house they built on the property has big north-facing windows that offer a spectacular view of the Northwoods.

It turns out, though, that the big windows, and their placement, are among the very few design features of the Chambers’ house that might compromise the home’s energy efficiency. After celebrating the completion of their house during Earth Week, the couple and regional power company WPPI Energy, whose GreenMax Home program helped offset the costs of efficiency upgrades during construction, commenced fine tuning the home’s energy use to bring it to net zero.

The GreenMax program, which also is available to architects and builders, provides funding to help defray the incremental upgrade costs of building or remodeling projects aimed at bringing a home to net zero. WPPI Energy also offers technical assistance and measures the newly built or remodeled home’s energy use and environmental impact.

Upgrade costs and incentives

The upgrade costs for the Chambers’ home – which totaled $89,000 for a building with 3,100 sq. ft. of conditioned space and 1,800 sq. ft. of finished space – were further offset by incentive funding from Wisconsin’s Focus on Energy program, as well as federal tax credits.

The cost of improvements to the shell came in at $13,000. They include a 2×8, 24 in. on-center exterior wall system, which accommodated R-25 batt in the wall cavity. The shell is covered on the outside with R-5 insulation. And, aside from those on the north face, most of the windows are horizontal and high up on the walls, allowing daylight to wash across the interior of the home and compensating in part for the fact that the home does not have overhangs.

Of comparable cost ($14,000) is the home’s ground-source heat pump system, although the biggest ticket on the upgrade bill ($57,100) was for the 5.76 kW ground-mounted PV system.

As an incentive for GreenMax program participants to walk the green walk in designing their home and managing its energy use after construction is complete, WPPI, through regional customer-owned power distributors, offers them a special buy-back rate of 30 cents per kilowatt hour. With the standard utility rate set at 10 cents per kWh, a net zero home using and producing 10,000 kWh of power annually stands to earn about $2,000 a year.

The Chambers submitted their design proposal to GreenMax Home in October 2007 and broke ground on the project in July 2008. Because their house is the first built under the GreenMax program, the Chambers have become its de facto ambassadors. Tom, a high-school principal, and Verona, a middle-school teacher, say they’re eager to use the house as a showcase for green building techniques and green living strategies.

“The best part of this process is certainly how much we have learned,” Verona said in a WPPI press release. “We have already begun to share our experiences, showing our house and discussing it with others. We are excited for tours and open houses to continue, as we hope to educate many people about this project.”