Our solution for this was to construct a 6m geodesic dome, cover it and create a greenhouse. However, the cover does not offer enough protection on the freezing nights…Time for another solution.
Rocket Mass Heater!
The solution to combat the cold, we built a Rocket Mass Heater(almost) to heat the greenhouse. This is not an exact copy of the original as we want to keep as much room for plants.
We started with the firebox. This was dug into the ground to about 50cm to use the earth as a heat source.
Then the exhaust chamber and the chimney, and finally covered it in clay.