Robust and cost efficient greenhouse construction for garden


Hello Open Agricultures,
I am in Hungary with about 2000hrs. of sun and 0 … 115 degree fahrenheit over the year. I would like to build a green house construction for my home garden at a size of 3-5m2 which should feed one person with vegetables and some berries all over the year. Actually the construction is one of my biggest challenge: It should be easy to build, robust and not expensive and consume only little energy. Maybe in winter time only corn salads, carrots and beets are possible to harvest.

I have been thinking about a hexagon facing 3.5 sides to south with 3 levels of 5 flower boxes inside. On the north side, there would be a door with the computer, valves, ventilation, LED and a smartphone mounted on it taking pictures and control the whole greenhouse. I am planning also to dig a water basin under the ground, maybe 5-10 feet deep to heat in winter time and cool in summer time.

Did someone already such a project? Could you help me with ideas, sketches?