The MAC Federal Credit Union in Wasilla, Alaska, is a prime example of how insulated concrete forms (ICFs) can be used to create a beautiful, energy-efficient, and resilient building. Completed in July 2021, the project was the Light Commercial 2nd runner up and People’s Choice Winner in the 2023 ICF Builder Awards. The MAC Federal Credit Union project used Nudura ICF blocks, with a total of 8,883 square feet of ICF used in the building, split between 8- and 10-inch core blocks over two floors, each 4,050 square feet. The ICF system was crucial to the project’s success, not just as a building medium, but also as a means to resolve many of the site’s challenges. ICF provided structure and a lower retaining wall, allowing on-grade access to two floors. The ICF system also surrounds a central interior elevator shaft, offering safe, quiet, and fire-safe operation. Overall building safety, including the bank’s vault, was inherently enhanced using ICF.
This building was designed to be the Wasilla branch and corporate offices of MAC Federal Credit Union, originally based out of Fairbanks, Alaska. “Through its design, the client wanted to evoke the sensation of coming home in the rustic setting that is Alaska,” says Seth Kroenke, Owner of Remote Alaska Solutions, the project’s general contractor, ICF installer, and form distributor.

Sustainability
The project maximizes the advantages of ICF construction by incorporating sustainable design elements. The lower floor has 2-inch rigid foam insulation below the slab with an integrated radiant in-slab heating system. The main level has a 5-inch thick slab on metal pan deck with an in-slab radiant system as well to amplify energy efficiency. Large, energy-efficient windows along the south wall provide many benefits to employees and guests alike. The windows utilize passive solar for heat gain in the winter as well as bring daylight into the building. Employee offices line the south wall and have large windows looking into the lobby as well. This allows all the daylight to pass through the offices and into the main lobby from the south. Simultaneously, large windows on the north side of the building let in ambient daylight directly into the lobby year-round.

Significance
The MAC Federal Credit Union is meant to be easily accessible for residents, built along one of only a few highways in the state of Alaska. Its highly visible location meant that the general public could follow along with its construction, and its speed of construction highlighted the practicality of ICFs in winter and also showed that there are no limitations to the architectural style or purpose that is capable of being achieved with ICFs. “Perhaps most importantly, it demonstrated that even small commercial entities can visualize ICF’s significant long-term value, thermal prowess, built-in seismic resistance in an area known to receive high-magnitude earthquakes, and the ability to withstand natural disasters,” says Kroenke. “In fact, its strength and wind-load resistance properties were literally put to the test less than six months after the building’s grand opening.” The Wasilla MAC Federal Credit Union building resides in a wind corridor and was affected by a catastrophic wind storm that hit the Matanuska Valley the first winter after the building was completed. The storm produced severe winds lasting close to a week, with sustained gusts reaching more than 100 mph in early January 2022. The state of Alaska even declared the area a “state of emergency” because of the extensive damage across the area. “The only damage to the building was that its commercial roadside signage was torn apart by the ferocity of the winds,” says Kroenke. “Otherwise, the ICF structure weathered the storm completely unscathed.”

Kroenke says this project is a beacon for ICF construction throughout their region. The MAC grand opening event was well-attended, with local media and the Chamber of Commerce helping to spread the word about the new building. The CEO of the credit union says a lot of people stop in just to see the inside of the building and find out what it’s all about.