Has anyone added a sunroom to increase the value of a home for the purpose of refinancing?

Looking at buying a 600sq foot 2bd 1 ba home.

I think you aren't getting answers because it isn't clear that doing that would actually increase the value. Does it increase the number of official square feet on the home? My guess is no, if it isn't heated, but I really don't know. Talk to a realtor or two who know that neighborhood and can tell you what does and doesn't increase value.