French doors are doors which include transparent or translucent window panels. They are an interestign option to spruce up your home with either inside or out. French doors can be hung as a single door or in pairs. There is a wide range of doors on the market including mass produced and handmade ones. To have a basic door installed by a professional expect to pay on average $200 per door. Don’t forget about additional costs such as casings, wood trim and paint which can add another $100 to your project.