A trefoil arch is a type of arch whose profile is built up from three intersecting smaller arcs, together forming a clover-shaped (three-lobed) opening. The trefoil arch is a typical Gothic element used in windows, niches, door portals and blind arcading.
Construction
The trefoil arch is constructed by selecting three centre points:
- Two lower arcs at each side — the ‘ears’
- One upper arc in the middle, positioned higher
- The three arcs meet with small cusps
This creates the characteristic clover-leaf shape. Variants include:
- Pointed trefoil arch — upper arc pointed, side arcs round — high Gothic
- Round trefoil arch — all three arcs round — Romanesque or Moorish
- Multi-foil arch (cinquefoil, septfoil) — variants with more lobes
Applications
The trefoil arch is used above:
- Windows — often in churches, cloisters and chapels
- Niches — to frame statues or sacrament cupboards
- Doors and portals — as a refined opening above an entry
- Blind arcades — in masonry as decoration without an actual opening
- Sedilia — three seats for clergy in the chancel
Symbolism
Like the trefoil ornament, the trefoil arch carries the symbolic meaning of the Holy Trinity. In churches it was therefore used systematically in liturgical spaces and entrances to remind visitors of the holy three-in-one.
Structural aspects
- Statics — all three arcs must rest on a supporting element
- Construction — often carved from a single stone block, sometimes assembled from several voussoirs
- Arch filling — often filled with tracery or trefoil decoration
Examples
- Westminster Abbey — trefoil arches in cloisters and choir screens
- Cologne Cathedral — in blind niches of the clerestory
- Many 19th-century neo-Gothic churches — trefoil arches as a leitmotif
Related terms
- Trefoil
- Arch
- Gothic
- Tracery
- Pointed arch
- Cusp
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