Choir Clerestory and Triforium Tracery (Durand)
The work of Renaud de Cormont in the 1250-60s. Renaud favored the trefoil--a form already used by his father Thomas in the nave triforium. Here, below, you see the reverse side of the choir triforium which is glazed, providing abundant light for the interior of the choir. In the clerestory, above, Renaud has elaborated his trefoils with trilobed cusping and capped the entire window with a gable, lending a "post modern" jagged look to the exterior.