A lunette is a semicircular or segmental panel above a door or window — the field between the straight lintel and the arch above it. The word comes from the French lune, moon, referring to the crescent shape. The same term is used in fortification for a small free-standing outwork with the same characteristic form.
In roofing the word is also used for a small subsidiary roof set at right angles to the main roof; that meaning is covered in a separate entry.
Meaning 1: the panel in the facade
An arch can be built over a rectangular door or window. The area created between the lintel and the arch is the lunette. It is usually given a treatment of its own:
- Fanlight — a semicircular or fan-shaped window bringing daylight into the hall; typical of eighteenth and nineteenth century town houses
- Relief or sculpture — on churches and public buildings
- Fresco or mosaic — in the Italian tradition
- Plain masonry or rendered panel — the simplest, solid version
Structurally this is more than decoration: the arch over the opening carries the load of the masonry above and passes it to the reveals. The lunette is the relieved area within the arch — it carries nothing, and can therefore be made light and open.
Meaning 2: the fortification
In fortification, a lunette is a small independent defensive work placed in front of the main rampart:
- Two faces angled forward, meeting at a point
- Two short flanks at the sides
- A gorge at the rear, usually open or closed only by a parapet or a wall with loopholes
That open gorge was deliberate: if the enemy took the lunette, it gave them no cover and they could be fired on from the main rampart. Lunettes were built as outworks of a fortress or as links in a defensive line.
Related terms
- Tympanum
- Bastion
- Moat
- Battlement
- Facade
- Window frame
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