HAAG Certified Reviewer

The correct answer is that exterior doors typically come with two holes drilled for the placement of hardware. This design is primarily due to the additional security features that outdoor door installations demand. Exterior doors are often equipped with deadbolts and doorknobs or lever handles. These require separate holes – one for the primary locking mechanism and another for the handle or knob. In contrast, interior doors usually require only a single hole for the latch mechanism because they do not need the same level of security as exterior doors. Sliding doors often have different hardware mechanisms that do not necessitate the same drilling pattern, while French doors, while they may come with hardware holes, are often designed to accommodate multiple locking systems that differ from standard exterior door setups. Thus, the requirement for security and functionality in exterior doors justifies the typical two-hole drilling for hardware placement.