The following resources show how to create a model greenhouse using dowels, 3D printing, and landscape plastic. This model is too big for the sustainable city model. Plans for this year include making it with 1/8" dowel rather than 1/2" . As such, the connectors made in Tinkercad will need to be shrunk down to accommodate this modification.
Link to Celeste's post - https://www.celestemoreno.design/post/diy-mini-greenhouse
Tinkercad File - https://www.tinkercad.com/things/6xlkpBI3ehp