According to American Institute of Architects adding an outdoor living space is in high demand by people looking to purchase a home. So adding an out door living space would definitely increase the value of your home.
While going over the article I noted there were features that were the most requested. Comfortable seating, kitchens, bars, and fireplaces all made top of the list, along with decor that shows your personality.
Check out this article at Southeastsun.com for more details.
Check out HGTV outdoor designs pages for more ideas on your ooutdoor space.