I'm planning on building a greenhouse and was thinking of building a subteranean greenhouse as it should reduce heating requirements in the spring and fall. From the research I've done they should be oriented with the long side running east west and a berm should be built up on the North wall. What I'm envisioning is a 12' wide 20' long greenhouse with an 8' wide 4' deep trench in the middle. I'd have a 2' wide ground level shelf at the back of the greenhouse with a 4' high back wall against the berm, 2' wide walkways on either side of a 4' wide raised bed in the middle and another 2' wide ground level shelf at the front (S side) I'm hopeful a propane powered greenhouse heater will be sufficient to allow us to start growing in mid to late March and harvest into mid October.
Cursious if anyone else has built such a greenhouse and if there are any lessons learned specific to use in AK.