Steve Tuckner admits he failed.

His goal: To build an “affordable” net-zero home.

So he picked an affordable neighborhood: St. Paul’s North End. Sold the spacious three-bedroom abode in Roseville where he lived for decades. Moved with his wife and two dogs into an apartment — and hired builders. That was over a year ago.

“Is what we did financially sensible? Hell, no. I’m gonna lose a ton of money on it. … We’re likely gonna die there, because we won’t get the cost back,” Tuckner admits. “I did it because I believe in it. What we did is on the bleeding edge of what you can do.”

Now, the 1000 block of Loeb Street will have a home worth three times the cost of anything next door, across the street or down the block. It’s 1,060 square feet, a single story with no basement — and all for the low, low cost of $400,000, not including the lot. It likely will be the North End’s first “net-zero” home.

“I was surprised when I got an address out of them,” said Ryan Stegora, an Apple Valley builder working as a consultant on the project. “All right, add the North End to the areas where there are high-performance homes.”

“Net zero” is energy-efficiency parlance for eating what it produces; maybe a little less. With a 4-kilowatt solar farm on the roof, 15½-inch-thick walls of poured concrete and foam, a 9-square-foot battery, high-performance air exchangers and a sealed plastic “smart vapor barrier,” Tuckner thinks it’ll be up for the job.

He — if not his wife, initially — got on the “net-zero” kick years ago, after visiting the renowned “House in the Woods” in North Hudson, Wis.: a spare-no-expense home built for more than $1 million.

That home had a symphony of bells and whistles. Solar panels that tracked the sun, weather-resistant exterior shades, wastewater heat recovery, you name it.

The owner of the house, Gary Konkol, had been reluctant to release the hard costs of his build — worried he would scare away less-affluent energy-conscious families.

But he needn’t have worried with Tuckner.

“We’re a three-Prius family,” Tuckner laughs. That is, he and is wife share a Prius between them, and his daughters, of course, each have one.

All joking aside, as a software engineer, “I like the idea of building something that is inherently very efficient. It’s not about adding a lot of solar,” Tuckner says. Sure, Konkol’s home was expensive — adhering to a more extreme, certified standard of energy efficiency called a “passive house” — but at least it answered a big question: Could you build a furnace-free home that could brave northern winters?

As the years went by, another question arose: How cheap could you go?

Tuckner’s wife, Angela Jerome-Tuckner, had been reluctant to find out. Sure, they were empty-nesters living in an increasingly vacant house, but the opening debates had been about upgrading. Not moving. The Roseville house they occupied for 19 years had always had everything they wanted: multiple upstairs bedrooms, a fenced yard, an attached garage. The new house, it would later turn out, has none of those.

But the cost to retrofit the Roseville home, adding appliances, new windows and insulation — including digging around their foundation — ran between $100,000 and $150,000.

“A hundred fifty to live in the same house,” Tuckner says, shaking his head.

Jerome-Tuckner admits a shake-up of that size was easier to stomach, since they had so many recent changes — her husband’s (now in remission) cancer diagnosis, their daughters’ graduations and her mother’s death.

After all that, “No, no, I really do like the idea,” Jerome-Tuckner now says.

Their goal was to find inexpensive land in the city, and a Ramsey County foreclosure auction turned up the North End lot for $13,000.

It was scary at the start, after some additional costs with an architect. They eventually decided to go without one, relying on builders and a consultant with a track record for net-zero builds.

And there were surprises. Even though they went without a basement, it would’ve cost the same to have one. The house that had been torn down on the lot left some shaky land, and they ended up having to pour concrete eight feet deep in places. That was $30,000 they could’ve saved.

Now, the frame is up, the walls are poured and wrapped, and Tuckner hopes the project will be done by February.

As for bells and whistles, “It’s about as bare-bones as I’ve seen. The solar is probably their one big expense — but if you want net zero, you have to have it,” building consultant Stegora says.

Still, the primary reason for the hefty price tag lies in the walls themselves: 6 inches of poured concrete, surrounded on each side by nearly 3 inches of insulated, Lego-like “concrete form” foam, with another 4 inches of foam inserted in the middle for good measure. No wooden two-by-fours. All that wrapped by a semi-permeable plastic barrier.

“The concept is very simple: highly insulated, and sealed up tight,” Tuckner says.

“It’s virtually an indestructible structure. It’s inert to moisture. … And these homes are super quiet. Once people live in them, they don’t want to live in anything else,” Stegora said. “The ones that go through with the build are typically not first-time homebuyers. Middle-aged, grown kids, owned more than one home.”

Without exception, neighbors admit to having as much sticker shock as the Tuckners did.

“How much?” asked an agog Judy Berg, who’s lived across the street from the Tuckners’ lot for 46 years. “All they did is raise our taxes!”

“I thought (Tuckner) was kinda crazy because of that,” said Angel Stettner, who lives next door. “But if you’re gonna live there until you die, it’s the quality not the quantity, I guess. If you’re comfortable.”

Stettner said she thought about buying the lot herself, but is happy to have the Tuckners as neighbors. “It sounds perfect for empty-nesters. Watching it being built is super interesting. They have foam, like Legos, in the walls.”

Joe Bowman, owner of Minneapolis-based Conscious Living Institute, the general contractor on the build, said the Tuckners could’ve saved a little on the walls — maybe $10,000, with a less expensive product that arranged the foam differently.

But all in all, if you take out the $30,000 the Tuckners lost on the extra work for their foundation, his net-zero low-ball estimates are about the same.

“It might be between $350,000 and $375,000, depending on the square footage, for a two- or three-bedroom with a basement,” Bowman said when asked the minimum a net-zero house might cost.

Those wanting net zero, he noted, don’t always have to go to such extremes with the walls.

“If you throw enough solar at it, you can get to net zero without doing any of the performance stuff,” Bowman said.

But Stegora said most of his clients are more concerned about resiliency and efficiency — not so much the fact that a home is pumping wattage from the sun.

Yes, Tuckner says, he failed in his goal.

“Our goal was to build an affordable net-zero. We didn’t do that. But we tried.”

And — given his anxieties about climate change — he’s comfortable living in that failure for the rest of his life.

“I’m not saying it’s going to save the world. It’s a stupid idea, it’s an obsession, all that, whatever. But one thing it will be is resilient,” Tuckner says. “It’s the kinda house that, given what’s coming, it’s the best thing for me, and my wife.”