West side of the upper south transept

The dark triforium with its generously scaled trilobe framed in a thin slab of stone (plate tracery) and topping three pointed lancets is the work of Thomas of Cormont, 1240s: the triforium and the sumptuous foliate band below continue without change from the nave. The clerestory windows above are by Master Renaud, c,1250, as are the exterior flying buttresses (invisible here).