Bill Newman's kayak buddies love to tease him about his new house in Brooklyn Center. It's too big for just one person, they say. It's a McMansion. And it's way too nice for him.

Newman just laughs. He erased his guilt about the home's size (more than 3,000 square feet spread over three levels) by packing it with sustainable features, including solar panels, geothermal heating, super-insulated walls and rainwater collection systems.

"I wanted it to be energy-efficient," he said. "I geeked out on the engineering aspects. Then it started getting out of hand."

His house, which he nicknamed the Eco Freak McMansion, is bigger, better and, yes, way nicer than what he's used to. Even though he's lived in his new house for several months, "I feel like I'm house-sitting for some rich guy," he said.

For 13 years, Newman lived on the same site in an eccentric 1940s cabin that had been dubiously "improved" by previous owners. "It was an odd little house," he said. "It had dark paneling, brown and orange swirl carpeting, and the front door [opened] directly into the master bedroom."

He bought it for its lot, which boasts 140 feet of Mississippi River frontage across from an island wildlife preserve. And he got a deal, which was good because he'd just been laid off, he said. "I was poor. I took my severance and started a groundwater cleanup business."

Newman added a few modest improvements to the house, making it "almost normal," he said. But his focus was on building his business, Remediation and Natural Attenuation Services, which he runs out of a detached garage/solarium next door.

Eventually the business was doing well enough for him to build a new house filled with green technology. He hired architect Pat Mackey of Mackey Malin to design a home that made subtle use of that technology.

"Most people's beef with solar panels is that they're not particularly pretty," Mackey said. "Bill is very interested in technology but not in wearing it as a coat." The 40 solar panels, each directly linked to a computer that Newman can monitor from his office, lie flat against the metal roof, which is set at the optimal angle for solar collection.

Originally, Newman was going to build a smaller one-story home with a finished basement. But he added another story to make the most of his river setting. "The second story is all about the view," he said. "It's definitely big for one person, but it's a great party space for hosting unruly kayakers. I have a great room downstairs, and an even greater room upstairs."

Mackey brought in Chuba Co. as general contractor because the firm had a track record working with SIP (structural insulated panel) construction, he said. (The 6-inch SIPs have an R-26 insulation factor.)

The new house has three times the finished square footage as the cabin, but it's three to four times more energy-efficient, Newman said.

It's also a lot more stylish, thanks in part to designer and kayak buddy Jackie Kanthak, who helped him pick out finishes, fixtures and colors, aiming for locally sourced and green materials whenever possible.

"He says he doesn't know about this stuff [design], but he has definite opinions," she said of Newman.

He wanted clean lines and neutral earth tones. The palette is designed to evoke the rocks that paddlers and campers see in Minnesota, Wisconsin and Canada, she said.

According to Newman, his directive to Kanthak was to keep things "Scandinavian blond and bland. There's not a lot of color or knickknacks. The focus is on the landscape."

That landscape is as eco-friendly as the house itself. It includes pervious pavers, a 3,000-gallon underground rainwater-collection system, a rain garden to capture runoff and no-mow fescue to reduce the need for watering and mowing. "I want zero runoff to the river," Newman said.

His Eco Freak McMansion will be open to the public as part of Saturday's Solar Tour, in part to show that sustainability can be beautiful, he said. "People think that, to be energy-efficient, you have to live in a berm and herd goats into the house."

Kim Palmer • 612-673-4784