Using the concept of the window, which is the interface between theinterpenetrating interior and the exterior of a building, the article showswindow joinery as an independent architectural detail with aesthetic valueexpressed in an artistic form. The author discusses the changing function ofthe wall opening and emphasises its timeless role: bringing light and air intothe building. Analysing successively the design assumptions of creators fromantiquity to modernism, the article illustrates the integrity of windows and thefaçade of buildings, which influence the visual perception of the developmentin a broader cultural, artistic and historical context.