Room rental / House hacking in Montgomery County Md.

[Kathy C.]

Looking at possibly buying a home to live in as a primary residence. I'd also like to reduce my mortgage costs each month as much as possible. Seems like plenty of homes coming on the market have basement rentals with full kitchens. Are these legal? If not, how would I make it legal? Are permits required to rent out a bedroom or two if I went that direction? Thank you