Hey there! I'm considering finishing a section of my basement to convert it into an office/gym area since we are running out of space in the small condo while everybody is working from home.

It's a 1920 built victorian house with fieldstone foundation. Though the upstairs have been nicely finished in 2010, they did the bare minimum for the basement. Concrete floor + mortar over the fieldstone.

I'm thinking of putting up drywall against the wall and ceiling (Professionals), add recessed light up in the ceiling (Professionals) and put down some vinyl plank flooring or carpet tiles (DIY) down to cover up the cave/hospital vibe in there, making it a bit more livable. (We have not had a flood in the basement as I know of, and we just changed the pump for HVAC last year. It does gets a bit humid down there in summer, but we had a humidifier, seems to get the job done.)

It doesn't have a separate entrance which means it can never be converted into a bedroom, thus I want to control the budget under 5k renovating this ~190 S.F. area.

1) Is this realistic?

2) For fieldstone foundation/basement, is using blue board and regular insolation acceptable?

3) Any gotchas that I am missing?

Many thanks to any suggestions!