Padua's city council previously postponed a plan to build a new auditorium 150 yards from the chapel because an expert survey concluded that it posed a risk to the building. Prof Frugoni said: "We know from that survey that the sub-soil is extremely fragile, so that digging the foundations for the skyscraper will affect the drainage and may cause subsidence to the walls of the chapel. Both could ruin Giotto's paintings. How could anyone contemplate taking that sort of risk?"