A bay window is an enclosed projection on a façade that extends outward at ground floor or upper-floor level — examples appear in almost every architectural style from the Middle Ages to today. Bay windows enlarge the living space, bring in more daylight and break up the flat plane of a façade. Here are the best-known types through history.
Medieval oriel
In medieval timber-framed buildings an upper storey often projected slightly over the ground floor — an early form of the bay window. Examples can be seen in Tudor towns such as Chester, Shrewsbury and York. The projection was usually supported by carved corbels or brackets.
Renaissance bay window
In the Renaissance (16th century) the masonry bay with stone surrounds appeared. Examples:
- Late Tudor and Jacobean manor houses
- Stadhuis (city hall) of Den Bosch (Netherlands)
- Patrician houses along the Dutch canals
Characteristics: cross-mullion windows, stone surrounds, ornate parapets.
Victorian bay window
During the Victorian era (1837-1901) the bay window became iconic in British terraced and semi-detached houses:
- Square bay — rectangular plan
- Splayed bay — chamfered corners at 45°
- Bow window — gently curved
Often two storeys high, with stone or brick pilasters and decorative pediments above.
Edwardian bay window
In Edwardian houses (1901-1910) bay windows became simpler and more spacious:
- Wider, taller bays
- Plainer detailing
- Often only on the ground floor
Bay windows in Art Nouveau and Amsterdam School
Around 1900 bays appeared with curved forms and stained glass:
- Often with leaded lights or stained glass
- Decorative brickwork with floral motifs
- Flat or pointed roof to the bay
- Found in continental European Art Nouveau and Dutch Amsterdam School architecture
Mid-century and modern bays
In post-war housing developments cleaner bay forms appear:
- Post-war housing — simple rectangular projections
- 1960s-70s — concrete with pebble-dash or timber cladding
- Contemporary architecture — minimalist glass cubes, sometimes cantilevered on steel or concrete
Structural examples
How is the bay window supported?
- On its own foundation — simplest, separate foundation
- Cantilevered — fully suspended, carried by beams or corbels
- On steel beams — modern solution for wide openings
Related terms
- Oriel window
- Bow window
- Cantilever
- Stone surround
- Mullion
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