Actually, a brick bottom cold frame.but yes, a sort of greenhouse. "You don't always need to build a big green house, why not try a mini greenhouse made from recycled bricks & windows"
Beautiful greenhouse / potting shed inspiration
Shop Cold Frames made of Cedar. Farmer D Cold Frames are made in USA. Extend your growing season with gorgeous cold frames from BlueStone.
Farmer D's Cedar Bed on Legs : Remodelista
"Old windows Greenhouse Idea" Super smart!