Building A Different Kind Of Walipini - Year Round Gardening Anywhere (video)
A greenhouse with a reciprocal roof frame, made by the students of the Creative Garden Wageningen, no video of inside just yet as it requires more work and will be made into an aquaponics paradise this season!
At a total cost of about $4,000, it's not too bad, and worth the yields that are to come. It will be long lasting, and brings in lots of light, while taking advantage of the subterranean climate control.
Being dug-in to the ground means when it's hot outside, the below ground temperatures keep it cool. When it's freezing outside, the ground and sun act as warmth, so the plants keep growing, and forget that it's winter. Here's a good source for your heirloom organic seeds to get ready for the Spring!