Mike and Jackie Sperr anticipate that when they finish building their 2,000-square-foot, earthship-style home next year, it will cost them practically nothing to live there.
Mike said, “Nothing will be standard.”
Jackie said, “We’ll be able to live off the grid.”
This makes the third summer they’ve worked on their home on 149th Street in Bock, and they think the finish line is in sight for next year. They’re working on walls and a roof this fall.
The young couple has documented their build on the Facebook page, Gifted Home Construction. They derive the concept from renowned, Arizona-based builder Mike Reynolds of Earthship Biotecture, which describes its homes as “radically sustainable buildings.” Earthship-style homes are technically defined as an off-the-grid home made from an earth berm and oriented for passive-solar heat.
The Sperrs said the homes typically cost between $775,000 and $1 million to have built. Since they’re doing all the work themselves, they expect the total building cost for their home to be in the neighborhood of $100,000.
One of the features of the home is the berm passersby barely notice from the road. Mike said they created the berm and then used the dirt they dug out to pack into old tires. The berm wall runs the length of the home and contains more than 750 “belted rubber forms,” aka used tires.
Jackie said, “There are basically four-to-six wheelbarrows of dirt in each one (tire).”
Mike explained, “You basically set them down like bricks,” and the couple attests they spent nearly all of the first two years collecting and situating the tires, which are set in concrete.
The front wall, said the Sperrs, will be 80 percent glass, containing 12 sheets measuring 4 feet by 8 feet. They built the berm so that the front of the home is oriented toward the south and east in order to maximize passive-solar potential. They said the earthship-style home heating systems have proven successful in Russia, so they’re confident they’ll stay warm.
The front of the home will essentially have a greenhouse-type buffer that will remain a constant 50 degrees and will surround another greenhouse where they’ll be able to grow everything from vegetables to tropical fruit.
The dirt walls serve as insulation on the home and hold in both warm and cool air. Mike said they won’t need a furnace, but the home will have one to meet code. Cool air generated in the shady areas of the home will be pulled in through tubes that are eight inches in diameter and about 20 feet long.
Interior walls of the house will also mostly be made the same way as glass-block walls, except the glass pieces are round. Each one is made from two bottoms of a large bottle that are put together so the bottoms are on either end, and the piece achieves that somewhat-obscured view seen through glass-block walls.
Jackie said they’ve collected, cut and assembled possibly thousands of bottles so far and that all their friends and family are excited to tell them they’ve collected more bottles for their house walls. She laughs that the couple doesn’t drink but has quite a collection of liquor and wine bottles.
Mike and Jackie said they installed three, 2,500-gallon water cisterns and anticipate that Minnesota rainfall will be more than enough to keep them full. The self-sustaining home treats the water from the cisterns to come in as drinking water. All the homes gray water will be rerouted to become water for the greenhouse plants and to fill the toilets. They said all the water coming into the house will be used five to six times except for what’s flushed out to the septic from the toilets.
Mike and Jackie agree they like their showers and basically planned a system that would enable each of them (in theory) to take an hour-long shower every day.
Path to an earthship home
Mike earned an architecture degree and graduated from college in 2008 as the housing and building market collapsed and recessed. He got a job delivering pizzas for Dominoes in St. Michael. Jackie works there, too, and they both like the flexible schedule and said the job works well for them to have time for building their home.
The two reflected quite a bit on what had happened with the housing market and marveled at how expensive it was to maintain a home. They visited with a financial advisor, who told them the two most expensive parts of retirement are housing and eating.
Mike said he then found the house that would cost nothing after it was built. It was a house that would take care of them instead of the other way around. He and Jackie said eventually, they’ll only have to work if they want a vacation.
They used to live in Brooklyn Park but sold their house there and live on their new home site in a camper-type vehicle. When the weather turns really cold, they stay with her brother in Milaca or with one of their parents.
Asked where they got all the tires for their home,
The “belted rubber forms,” as they’re called in building, came slowly at first then a friend of theirs had several truckloads of used tires dumped onto their property. The Sperrs were able to take 300 of the tires off their friend’s hands.
The couple has busy, sweaty, back-breaking days on their new home site but said they’re excited to have completion of the build in sight. They plan to hold some kind of open house when they’re finished to share the milestone with friends, family and community.
Jackie said, “When you see these things when they’re finished, they’re really quite magical.”