The return on investment on a mid-range bath modernization is 102% of its cost. Kitchens can add about 90% of their costs to the home's value.

Another home improvement that can pay off is window replacement. Not only does this job return about 90% on investment when the house is resold, it saves on energy bills every year.

As a rule, upscale improvements pay off at lower rates than mid-range or inexpensive ones. And making a house bigger and more luxurious that those of your neighbors will also cost a lot more than they'll return when the house is sold.