Replacement, in three phases, of 360 steel windows installed in 1917 by new steel window replicas with recuperation of brass hardware.

Restoration of stained-glass windows of the Bishop's Chapel, registered historical monument since 1993.

Reconstruction and restoration of stained-glass bishops' coats of arms in public and private apartments.

Addition of stained-glass painted banderols with descriptions of coats of arms.

Maitre-verrier: Detlef Gotzens.

Completion: 1998-2004