Any improvement can increase the value of your home. However, remember that the value of your home is really dictated by the market/buyers. For that reason, it's important that 1) the improvement is one buyers will recognize and be willing to offer more for and, of course, 2) it is a worthwhile upgrade (i.e. the roof needed to be replaced). A buyer may very well be willing to offer more for your home as compared to a similar home in need of roof repairs.