Source: Go Banking Rates —
When overnight guests visit your home, you want them — and the rest of your household — to be comfortable. If your current situation isn’t ideal, resulting in your visitors or your kids sleeping on the couch, you might be thinking of adding a guest room onto your house. Of course, you want to make sure it’s a sound investment.
Since property values vary greatly across the U.S., it’s hard to put an exact dollar value on the amount you should spend. Many factors go into this cost, including property values and demand in your local area.