Arctic foundations of the future

With coastal erosion and permafrost thaw accelerating across Alaska, forcing homes and entire communities to relocate, one of the great challenges is building foundations on unstable ground. CCHRC has worked with villages, permafrost researchers, and housing authorities to help design foundations for these dynamic conditions.

On the North Slope, CCHRC worked on a skiddable foundation that allows the house to be moved to a new location if needed. Most homes in this region rest on wood pilings driven into the ground, which accelerate permafrost thaw by conducting heat into the frozen ground. As permafrost thaws, the ground around it settles, making the home less and less stable. These changes forced the regional housing authority to begin installing cross-bracing to homes’ pilings to prevent them from leaning and shaking.

The skiddable foundation ensures homes are ready for more of this kind of movement in the future. It includes a pier and pad system that not only elevates the building from the ground but can also be adjusted to respond to seasonal settling or permanent changes. Telescoping steel posts attached to the pads can slide up and down, and the beams supporting the home double as skids. If the house needs to be moved, it can be lowered to the ground and towed to a level spot.

A different type of adjustable foundation was used in Mertarvik, the first full community relocation in Alaska due to climate change. CCHRC worked with the village to design an energy efficient, resilient home that could be built in stages and moved as community infrastructure was developed. This required foundation that could be moved across the tundra and possibly ice. The resulting “Triodetic” foundation consists of a very rigid aluminum frame that sits on top of the soil and keeps the building level in the event of shifting or settling. With a multipoint framework, it can adjust in many directions to counter any moving ground. The aluminum frame rests on three ski-like tracks that allow the house to slide across ice or tundra.

The first demonstration home was built in 2016 and was moved to its final location in 2019, when roads, lots, and initial infrastructure were completed. The same year, 13 additional homes were built incorporating many of the technologies used in the prototype home.

While there is an urgent need to develop resilient buildings and infrastructure in the north, the concept of moveable homes is nothing new in Alaska.  In fact, First Alaskans lived for thousands of years by migrating seasonally and adapting to changing conditions. The western approach of fixed infrastructure that has has been adopted in the past century is not always the best fit for a place that changes as dramatically and as quickly as Alaska. To continue to build permanent infrastructure in this environment requires a long-term view and an eye toward resilience, and also adds cost and complexity to building projects.