The exclusive deep GRP cill is available as standard on the Vintage sash window is a beautiful feature designed to achieve the authentic appearance of an original 3” timber, useful for use in a Conservation Area.

The deep 56 mm cill is indistinguishable from the other PVC-U sections because all are bond wrapped in the same Renolit foil to maintain the appearance of timber.

The deep cill is 16.8 times stronger than a regular cill and this strength allows larger and unusual windows to be replicated more authentically, for instance where required in seafront hotels, renovated/converted former schools, industrial buildings, and ecclesiastical buildings.