Glossary Glossary of Architectural Terms Facade: The front face or exterior of a building, often representing its architectural style and character. Atrium: An open central space within a building, typically featuring a large skylight or glass roof, providing natural light and ventilation. Balustrade: A row of small columns topped by a rail, often used as a decorative barrier along balconies, staircases, or terraces. Cornice: A decorative molding or projection that crowns the top of a building or separates the walls from the roof. Dormer: A structural element projecting from a sloped roof, typically containing a window and providing additional headroom or ventilation to an attic or upper floor. Eaves: The lower edge of a roof that overhangs the walls of a building, providing protection from rainwater runoff. Fenestration: The arrangement, design, and proportion of windows and doors on a building facade. Gable: The triangular portion of a wall between the edges of a sloping roof, often featuring a window or decorative element. Lintel: A horizontal structural element, often made of stone or concrete, that spans an opening such as a door or window to support the weight above it. Mullion: A vertical structural element, typically made of wood, metal, or stone, that divides the panes of a window or supports a series of windows within a single frame. Parapet: A low protective wall or railing along the edge of a roof, balcony, or terrace, typically serving both functional and decorative purposes. Pilaster: A flattened, rectangular column or projection attached to a wall, often used for decorative purposes or to provide additional structural support. Portico: A covered entrance, typically supported by columns or pillars, leading to the main doorway of a building. Quoins: Decorative masonry blocks or stones that emphasize the corners of a building, often used to provide visual interest or structural stability. Sill: The horizontal bottom portion of a window frame or the base of a door frame, often made of wood, stone, or metal. Transom: A horizontal bar or structural element that separates a door from a window above it, often allowing additional light and ventilation into a room. Vault: An arched ceiling or roof structure, typically made of brick, stone, or concrete, used to cover a space such as a hallway, room, or chapel. Wainscoting: Decorative paneling or woodwork that covers the lower portion of a wall, typically installed to protect the wall from damage or to add visual interest. Xystus: An ancient Greek architectural element, consisting of a long, colonnaded walkway or covered portico, often used for exercise or leisure activities. Ziggurat: A stepped pyramid-like structure, often associated with ancient Mesopotamian architecture, used as a temple or religious center.