We never recommend installing double-sided (keyed on both interior and exterior sides) deadbolts. Some homeowners desire double-sided deadbolts when there is glass in the door or in close proximity that would allow a potential intruder to break the glass, reach in, and unlock a single-sided lock. But double-sided locks also present a possible hazard to the homeowner. In case of fire or other emergency, they can interfere with the evacuation of the home. Quite simply, if the smell of smoke awakens you in the middle of the night, you do not want to worry about finding or using a key just to get out of the house. This is especially true when there are children or visitors in the home. Other than the fact that a key must be used to unlock the door from the interior, double-sided locks provide no greater security than a single-sided one.