However Palace aides insist that a longer opening period is not feasible as it would interfere with official business
Some £32 million of work is needed on the royal estates, which include Holyrood in Edinburgh – the Queen's official residence in Scotland – Balmoral, her summer base in the Highlands, and Clarence House, the home of Prince Charles.
The state rooms at Windsor Castle and Buckingham Palace have not been painted since the monarch came to the throne 57 years ago, while the electrical systems at the Palace have not been updated since 1948.
Meanwhile, £3 million of work is urgently needed at the magnificent burial site of Queen Victoria and her husband Prince Albert at Frogmore House, near Windsor Castle.
Completed in 1871, the mausoleum has been awaiting restoration for 14 years and is on English Heritage's buildings at-risk register.