Should I add a room to each side of my 1/1 duplex?

[Shane R Smith]

Should we add a room? Background: We are in contract on our first duplex. It's a 1/1 each side with a full basement. We are looking to add some value to the place and we were thinking of how we could add a room. So my thought was add an ingress/egress basement window and make a bedroom downstairs. Next steps: Seems a bit unique so I'm not sure how much I could bump the rent. Does it count as a 2/1 rental or somewhere between? Need to get a decent ROI on the add if I go through the work. Thoughts and advice would be greatly appreciated! Thanks!