My guess is crafting will first be available in the Tower of Trem as the Masters Lab quest would indicate that a crafting station will be located behind the doors on the second floor.
From there, I'm sure each town (N.G. craft station might be very near your house) will have some access to crafting, with various NPCs being able to craft/teach you how to craft unique items.
BTW, the house will end up being one of 'locked' door in N.G. if you want an idea of where it may end up, with the tower being a guide to what may be inside, as stated above.