We use about 1100' spread out on our property.
Had been just the double garage 500', dubbed the garagio (I know real original). Just added and bringing online a 300' free standing studio with a cedar deck along the front for spring/summer drying. The business has also absorbed two bedrooms for another 300' for office and staging/photo/packing and shipping.
I will be adding a brick patio 'kiln' area housing a pit, raku and gas kiln and will be adding and additional 200' building, finished out and used initially for stock and inventory.
It does take over the place but wow it saves a fortune when compared to renting 1200-1500 feet of studio space and paying monthly rent, triple net and utilities.
We live in a neighborhood of 1 acre homes sites so we are not much bother to our neighbors. The new kiln area will be about a football field from anyone's house (except ours :-) so I am hoping it will continue to not bother anyone. Most of our firing will remain cone 6 electric so this should work.