What kind of workshop? If woodworking, you may find a lot of sawdust will migrate upstairs. If painting, finishing, etc, provisions will have to be made for ventilation.

randy427... Thanks for the feedback. Yes, there would be some woodworking. So a ventilation/exhaust won't be enough? Is there a way to make a woodworking workshop work in the basement?

Having had a basement workshop for years (woodworking and metal working) the biggest problem was always getting larger pieces of material in and out.

Dust control is not all that hard with a decent cyclonic dust collector system (luckily metal chips do not tend to go very far anyway, though cutting oil can smell).

Large pieces of wood (like 4x8 foot sheet goods) are a real PITA to move in, and even larger lumber pieces can be a problem (I cannot imagine moving a 16 ft x 44 inch x 4.5 ft mahogany plank down a staircase).

I now have a basement shop, but have a floor level door that exits to a walk out garage (and the really large pieces are still a little bit of trouble).

I often end up chopping raw materials down in the garage to more manageable sizes.
. The other issue with a basement shop is humidity.

Metal working tools (lathes, mills, shears) can be kept oiled easily enough, but wood working tools are a little tougher to protect without running the risk of contaminating materials and producing finishing problems.

A hear gun, paste wax, and buffing can put a hard wax coat on woodworking tools (table saw tables, band saw table, drill press tables and columns, etc.) to protect against rust. I end up doing mine about twice a year.

Microfine sawdust almost invisible to the naked eye can wreak havoc in your HVAC system

"Microfine sawdust almost invisible to the naked eye can wreak havoc in your HVAC system"

If it is that fine it goes right though.