I'm just getting into bookbinding. It requires surprisingly few tools and not a ton of space (though like all hobbies it can always grow to consume whatever space is available). Its a good option if you have access to a printer with free or cheap prints.

Balcony gardening can be satisfying but might not be what you're looking for.

If you already have a project (or lots of them) in mind, a 3d printer can be great to have around. Depending on your fillaments of choice (determined by what you want the print to be able to do) you might need good ventilation or an enclosure. If you have a spare bedroom that's a good start.