clerestories

A clerestory is the upper part of a building's wall that contains a band of windows elevated above eye level to admit light, typically situated above an uninterrupted interior space such as a nave. The term is most commonly used in church architecture, but can also describe high windowed walls in secular buildings.

In medieval and especially Gothic architecture, clerestories sit above the arcade and any triforium, providing daylight to the central space and often housing stained glass. The design evolved to maximize daylight while maintaining structural support for the roof, with windows grouped to form tracery and vertical emphasis.

Function and impact: Clerestories illuminate interior spaces, reduce the reliance on artificial lighting, and contribute to spatial perception and color quality through glass. They can also aid ventilation when windows are operable. The amount of light is shaped by window size, glazing, and the overall roof geometry.

In modern architecture, clerestories remain a common device for bringing daylight into large rooms, often with energy-efficient glazing and operable sections. The concept also appears in vernacular forms and contemporary designs, where the clerestory line may be lowered or integrated with skylights for varied light control.