The story I often see is that of old janitor closets being converted into reconciliation rooms.I think this is probably right on. Perhaps the hidden away Reconciliation Rooms were the result of bad renovations in the wake of Vatican II. They tried to use an existing space to create something. Newer churches, built from the ground up, have thoughtfully integrated Reconciliation Rooms and Confessionals into the design from the beginning.
I live on the west coast where even 1970s churches can be considered “old”. (Please Note: This uploaded content is no longer available.)