Housing Resources Guide
Strong, quiet, and energy efficient
By Roz Kohls, Staff Writer
Allan and Becky Sorenson of Cokato discovered a new and increasingly popular type of construction for the dream home they are building in the country.
Their five-bedroom Craftsman style home is built with Insulating Concrete Forms, ICF.
“They stack in sections like Legos,” Becky said.
The forms are 2 1/4-inch slabs of insulating polystyrene foam “sandwiched around the concrete,” Allan said. “Air can not get through,” giving them high energy efficiency.
Becky said that they will be able to get R-50 from this house, which is under construction in the Bear Lake area southwest of Cokato. An R value is how insulation is measured. The higher the number, the better the insulation is.
Each stackable unit of ICF starts with two upright slabs of foam facing each other like two slices of bread in a sandwich. In between are plastic strips that run perpendicular to the planes of foam insulation, she said.
“They put rebar down in there before they put the concrete in for strength. They put really strong bracing around it before they fill it with concrete so it holds its shape,” Becky said.
“It’s extremely energy efficient. No tornado is going to take the house down,” Allan said.
“They are exceptionally quiet,” Becky added. She told a story about a drunk driver who was careening down a city street and crashed his vehicle into an ICF home. The couple sleeping inside never heard the roar of the vehicle’s engine nor the crash. They slept through the entire incident, she said.
The Sorensons’ new home also features a walkout basement.
“It (ICF construction) also creates a basement area that is much more livable,” Allan said.
Energy efficiency is important to the Sorensons because they intend to retire someday in this home in the country and be able to afford fuel on a limited income. Becky works for Meeker Co-op Light and Power Association and sees on a regular basis the cost of energy is rising, she said.
“Even if we go to alternative (power generation) it’s not going to do anything with the price,” she said. “We want some control over our monthly costs.”
ICF basements are not new. Homeowners have been using the forms in basements for the past 10 to 15 years. That is how Allan found out about the energy efficient units. He noticed a contractor was filling ICFs in a basement under a home near Cokato Elementary School and was intrigued with how flexible the forms were for construction.
The contractor, Roy Marttinen of Blue Fin Builders of Buffalo, is the same contractor the Sorensons hired to do their new home.
“You have to be very careful of the contractor, though,” Becky warned. The Sorensons were checking out the work of other contractors using ICFs and not all of them erected the forms into straight walls.
‘You can’t straighten it out after-the-fact,” Allan said.
ICF construction presents a challenge for electricians because the conduits have to be placed perfectly before the concrete is poured. “You have to do some preplanning,” Becky said.
However, the forms come with strips to which drywall can be attached, she added.
“The construction of ICF homes is growing about 30 percent a year. You can use them anywhere,” Becky said.
Becky estimated their new home is two-thirds done. The Sorensons installed moss green cement board siding. “It’s absolutely very low maintenance,” she said.
The cement board siding is guaranteed to last 50 years. Becky calculated they saved $20,000 not using stucco, she said.
“My husband has wanted to live in the country ever since we moved to town 15 years ago,” Becky said.
Allan grew up on a farm and was attracted to the site’s woods and nearby water, he said.