A traditional roof window is the historic, often craftsman-built form of a window in the sloping plane of a pitched roof. In modern construction the prefabricated roof window (such as Velux) dominates; the traditional roof window is mainly found in listed buildings, historic loft conversions and older specifications. The window follows the slope of the roof and provides light and air to the loft.
Difference between a traditional roof window and a modern roof window
Although the terms are often used interchangeably:
- Traditional roof window — timber frame, single or double glazing, often with glazing bars and small panes. Suits the original architecture of tiled, thatched and slate roofs
- Modern roof window — prefabricated, well-insulated unit (such as Velux or Fakro) fitted between rafters and connected to the roof covering with a standardised flashing kit
In heritage and listed-building work this distinction matters, because a modern roof window is often not consented in a listed building or conservation area. There a heritage-pattern roof window or a special conservation model is used.
Historic roof window types
Classic roof windows come in several forms:
- Leaded-light roof window — simple timber or metal frame with thin glazing bars and small panes
- Cast-iron roof window — 19th-century factory roof light, often used on warehouses and industrial buildings
- Pivot light — manually rotating window offering both ventilation and sky view
- Roof hatch — small hinged opening for emergency egress or maintenance
Application in new build and renovation
In new build, insulated modern roof windows are almost always used today because single glazing does not meet building regulations and listed-building rules set requirements for U-value and air tightness. In the restoration of listed buildings, original roof windows are often restored or replicated in a heritage pattern, frequently with concealed secondary glazing to improve the U-value.
Related terms
- Roof window
- Roof light
- Skylight
- Listed building
- Dormer window
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