Planting peas tomorrow. Glee! And I got my bareroot trees shipped in and planted per Tilted Irish Kilt’s instructions, so I am totally blaming him/her if they die.
We have a defunct swimming pool about fifty feet from the garden, and I am eyeballing it with thoughts of creating a sunken greenhouse for tropical plants in 2018.
I am assuming that the defunct pool is subterranian.
If so, I would cover it with 6 mil plastic over a conventional truss system ( ie: "MM)that is sligthly elevated for rainwater drainoff to determine if glassing later is worth it,
also, with a truss framing, plastic could be removed and replaced with "shade cloth" for summer heat.
Also, a truss 'tent-like' structure at surface level would provide ease of installing ventilation at either end since heat rises to the highest point
If subterranian, you should have access to a drain pump to avoid accidental excess moisture that otherwise could lead to 'dampening-off', mildew, and fungus control issues.
Sorry to hear that I wasn't there at the time of the planting to supervise or participate - P.S.: that voids the "T I K warranty"