The Palace was built using Anston limestone because it was cheaper and ideal for elaborate carving. However, the stone quickly began to decay and little was done to prevent its decline during the 19th century. Pollution has accelerated damage to the stonework. Some stone cleaning and restoration work was carried out in the 1980s and 1990s but there is still a huge amount of vital work to be done. Much of the scaffolding around the Palace today is there to protect people from falling masonry. In 2018 a chunk from a stone angel fell off the Victoria Tower and landed in Black Rod’s garden. Nobody was hurt.