A second story would be a good move economically if you home is relatively small for the neighgorhood, and if the costs to complete the addition are such that you don’t end up with the biggest most expensive home around. Also keep in mind this project will make you home unlivable for a period of time, and it involves demolishing the roof and potentially upgrading the foundation. Sometimes its a better idea to move to a bigger home unless the property is especially valuable.
Try to find building plans for your existing home, especially foundation details for your existing home. A second story addition will require a minimum size footing to support the structure. If you existing foundation does not meet this standard, it may be possible to tie in additional depth and width of footer, but it does complicate matters. You will need complete plans and permits to proceed. A good starting place would be your local building department where you can get a copy of building and plan requirements. From there you can decide if an addition is worthwhile, or if perhaps it is time to sell and move to a larger home.
