Hi @cardoprimo. I really like this post. And your cold frame seems to be one of the most professional ones I have ever seen. Evnen looks mor like a micro Chinese Solar Greenhouse. Well played and can't wait to read more about your Permaculture journey in clod Pyrenee Spain.
Happy you like it !
I like the design of those greenhouses too,we were thinking about a similar design from the terrace wall but changed because we don't have a direct south facing slope and we have to deal with some periods of heavy snow.
Hopefully see you around here too,
Salud