If you're gonna do any thing that fumes - resins, casting metals, etc - you'll wind up outside! Then, wish you had a separate shop! A mate in NZ is building his new place as a 3 story - ground floor is his shop then the first and second (above the shop) start off on a 12 inch concrete and rebar slab. The BEAMS in the shop ceiling are MASSIVE 14 inch I sections) - but he's got a lotta gear to move around - cars etc. He figures the concrete will do most of the sound barrier then he's plans on putting a flooring and insulation above that too. So far he's just got the shop done! Guess thats his priority - they're still living in the temporary house! If you're in the right spot of the US consider adding passive solar or slab heating to cut heating costs of you shop.
:cheers: Jim
Experience is the BEST Teacher. Is that why it usually arrives in a shower of sparks, flash of light, loud bang, a cloud of smoke, AND -- a BILL to pay? You usually get it -- just after you need it.