We have some friends who have a vacation cabin in the Yukon. It is very… rustic, to say the least. It has been passed down from great grandfather to grandfather to her dad and five uncles. The only access is by boat across a very large lake. There is no power or plumbing. The entire property has been built up from materials they have sourced from the surrounding forest. This is the Yukon Territory in Northwest Canada. In other words it is cold. Very, very, very cold. Normally they spend one summer month up there every year. However, her goal is to spend an entire year on the property with her husband. Yes, they want to do the whole Henry David Thoreau thing.
I think this “Solar Furnace” looks like a low tech solution that may be a possibility for their cabin’s heating needs. Very few materials are needed for the project to be completed. It is so simple and easy to make. Take a look at the video for instructions. Looking for more info on solar heating? Mother Earth News has another one for you to check out.