On 20 November 1992, a fire broke out in Windsor Castle, the largest inhabited castle in the world and one of the official residences of Queen Elizabeth II. The castle suffered extensive damage and was fully repaired within the next few years at a cost of £36.5 million, in a project led by the conservation architects Donald Insall Associates. It led to the Queen paying tax on her income, and to Buckingham Palace, the Queen's other official residence, being opened to the public to help pay for the restoration work.