Originally, Michelangelo planned for a skylight, but Clement VII believed that it would cause the roof to leak, so clerestory windows were incorporated into the west wall.
Asalnya, Michelangelo merencanakan suatu lubang cahaya, tetapi Klemens VII percaya itu akan menyebabkan atap akan bocor, sehingga jendela-jendela clerestory digabungkan ke dalam tembok sebelah barat.