The castle has almost dried out, only 5 per cent of the 1.5 million gallons of water poured over it remains, and the delicate stage of recreating the state apartments is under way.
Alan Frost, one of the team of architects, said: "This is the largest castle in the world still occupied; it's the Royal family home; it's the national banqueting hall; and it's also open to the public as a place of heritage. There has been nothing like it on this scale this century."
More than 100 rooms, out of 1,000, were destroyed by the fire in November 1992. Nine state rooms were left unrecognisable, including St George's banqueting hall. The restoration, led by the Duke of Edinburgh, will be completed on time in 1998 and on budget, pounds 40m.