A threshold, also known as a doorsill, is a functional component installed at the base of a doorway. It bridges the gap between flooring materials and provides a smooth transition from one room to another. For instance, a raised piece of wood, metal, or stone situated directly underneath a door exemplifies this architectural detail.
This element serves several crucial purposes. It prevents drafts, water, and debris from entering a structure, thereby contributing to energy efficiency and maintaining a comfortable interior environment. Historically, these features have been integral to building design, offering both practical utility and aesthetic enhancement to the entryway.