Huge 2600sqft Basement! - Seeking Value Add Recommendations

Hey BP Community!

I've been fortunate enough to secure a 4-plex in the Midwest from an investor that has excellent figures; cashflow is 12%+ as is. All units (2/1 and 1/1s) are on are on the main level and everything is virtually on auto-pilot. Then there is (**drumroll**) 2600sqft Basement!  We've obviously considered additional apartments (most expensive) all the way down to storage which is basically free.

What would you do with all this space to create value and incremental profits?

- Basement is concrete block, in great shape

-  Lots of clearance, probably 8.5ft

- No egress windows

- Small town of 700, median income 53K

- 1 bed 1 bath rent is $550