Three reasons not to build on permafrost
- Permafrost is unstable and no matter how much gravel and insulation you put under the house it is still likely to move or sink as the permafrost thaws underneath causing expensive repairs.
- Permafrost seems cheaper than good, solid, well drained ground but its not. You get the ground for a lower price but the development of the land is expensive. Septic systems for permafrost soils are expensive and prone to failure.
- Permafrost is a bad investment because in the end the structure you build may not be worth what you put into it, be hard to sell because everyone knows the permafrost is melting, or it might just fail.
Read more about problems building on permafrost below…
IF you are going to build of permafrost here are some of the additional costs associated with the cheap land you bought. You will need to purchase Typar fabric roll out under the potential hundreds of yards of gravel you will need for a driveway and building pad. One hundred feet of driveway will cost $2000-3500 if your land is relatively flat and dry. An average large cabin footprint is 16′ x 24′. A good building pad for this structure would be 36′ x 44′ so you can have flat, dry ground to work on and help keep the ground frozen. The pad should be compacted tailings to at least 3′. This is an additional 30-40 yards of material costing $8,000-10,000. Now you build your cabin and in five years are calling around looking for someone to level it even though you took all the good advice about building on permafrost under advisement. A simple cabin leveling or foundation adjustment in Fairbanks, Alaska will cost $1,800. An expensive cabin or home leveling can cost upwards of $20,000. Once, you get your house leveled it will slowly creep back into the swamp causing frustration and more money wasted as you get it leveled again. This scenario is common enough but let’s think about your house now.
Running water in a home built on permafrost requires a septic system and a water holding tank. There are basically two options for septic systems on permafrost in Fairbanks, Alaska: a mounded system above ground or an engineered water treatment system. Both options are bad. The DEC approved, mounded septic is built to fail. I can honestly say that I never hear about these system unless they have failed. No one has ever said that they work for more than a handful of years and even if it lasted ten years, you are still looking at replacing it at a price tag of $10,000-15,000 X 2 (X 3…..). The engineered water treatment system for a 2-4 occupancy home costs $20,000 and up not including the gravel pad and related preparations. Now there is another thing to consider when your home built on permafrost starts sinking back into the ground- the connection to your septic. That connection is inevitably spray foamed. The spray foam needs to be cut away and then pipes re-connected. Second, your septic may sink too or flood so it’s not functional. When you see a remember house that was a cabin and now has an addition that holds a water tank and bathroom that the heavy addition will sink at a different rate than the house. Do a little math and building on permafrost adds up to an investment that will likely go sour, cause frustration and even heartbreak when your little home in the valley becomes a nightmare that you try to sell to someone else.
With hotter summers and warmer winters we are seeing rapid changes in Goldstream Valley and other low lying areas in and around Fairbanks, Alaska. It’s just a bad idea to build on permafrost. Think twice before you buy that land that is ice laden or poorly drained. Don’t take my word for it, ask the neighbors and friends nearby to where you are thinking about buying. I have a lot more photos of homes that need leveling or are sinking into permafrost but I’m not posting them because I want to protect the privacy of people having these issues. Anyway, I have been asked about building on permafrost over and over by friends, neighbors, and clients who want to build on permafrost in Goldstream Valley so I created this page for the community I don’t know. Good luck out there!