What's new at the Minnesota State Fair Eco House? Zero, as in energy usage.

This year's demonstration dwelling, designed by SALA Architects, boasts a net-zero strategy, meaning it can produce as much electricity as it uses. The house, approximately 2,200 square feet, includes three dozen solar panels and a geothermal heat pump. It's designed to work with the existing electrical grid, drawing from certified green energy sources at night and on cloudy days, and feeding energy back into the grid on sunny days, said architect/project leader David Wagner. It's also carbon-neutral, using no fossil fuels. And if you want to build a replica for yourself, you can. This year's Eco House is not just a showcase but an actual prototype, with plans available for purchase.

The Eco House is long and narrow, designed to sit on a standard city lot, Wagner said, and its solar panels are integrated with the house in a clean, contemporary way, to look at home in an urban neighborhood.

"We're trying to put forth the idea that this [net-zero energy usage] is possible," Wagner said. "The technology is here today." It costs a little more up front, but reduced operating costs make it cost-effective over the long run, he added.

Other green features include electrical appliances, super-insulated 12-inch-thick walls, and eco-friendly finishing materials, such as wheatboard interior walls, recycled glass tiles and a kitchen countertop made of crushed walnut shells in resin. The house will include a carport (designed to house a plug-in electrical car) with a green roof and a demonstration rain garden. Visitors can tour the house free of charge as part of the Eco Experience in the Progress Building. The Minnesota State Fair runs tomorrow through Sept. 7.