Thanks for taking the time to contact us at 3 Blind Mice! In response to your questions, custom shutters can generally be mounted both inside or outside the sill depending on how much the window sill depth is.In this picture, the shutters are actually mounted inside the sill but the wood frame wrapping around makes it look like it's mounted on the outside. By using a Z-Frame shutter, you can accommodate most recessed window sills. Thanks again for the great question.

If you need any more information or are interested in exterior coverings, please feel free to contact us directly. www.3blindmiceusa.com