The Green Door is a door you can build (the Hearth kit).
In-game description
A green plank door with iron straps and a little heart cut out. E opens and shuts it.SHOWN IN THE BUILD RING
Building it
It costs 3 
Wood, 1 
Cotton Grass, 1 Water 1 Wind spirits. Take it down with DISMANTLE to get its cost back (see Building).
