When considering add ons, remodeling, upgrades, please consider doing what you want to your home for you first, and as an investment or "adding value" second. I am pretty sure I donâ€™t need to tell you, most Americans are upside down in their homes, so if you are going to live there, enjoy it and so what you want. Trying to add value at this point, to a property that has most likely lost value for anyone who has bought it since 2005 (really depends on where you are, your local market and etc) it really will not help much. As a general rule, upgrades & remodel to kitchen and bathrooms have the most/best chances of gaining the most for your dollar.
All that being said, you live there, and if that helps you enjoy the property, gather at least 3 separate bids from licensed and bonded contractors and go for it. Best of luck.