Balmoral is to be turned into a centre of public memorial for the late Queen, under plans to welcome visitors into royal residences for more of each year.
The Scottish home, where the Queen spent her final summer before her death on Sept 8, is to be further opened up to the public with ambitions to make it a hub for visitors to reflect on the Queen's life.
The plans could see the house used for exhibitions with a permanent space to honour of the Queen's life and legacy.
The King will not use it as his main Scottish residence, preferring to stay at nearby Birkhall on the estate. Birkhall, where he has already spent the period of royal mourning, once belonged to his grandmother the Queen Mother, who described it as her "little big house".
The Royal family are expected to continue the late Queen's tradition of spending summer holidays together at Balmoral, at which point it would be temporarily closed to visitors. Recent years have seen it open only partially from April to July.
New model for residencies
The King is understood to hope to use the Scottish home as a blueprint for a new model of using royal residences, which would see visitors welcomed in even when he is staying there.
Sources said he hopes to repeat the success of Dumfries House in Scotland, where he works in rooms above the front door as tourists come and go, and Highgrove in Gloucestershire where he is regularly in situ as the public explore the garden.
As the King explores how best to use the portfolio of private homes and official royal residences already belonging to him and inherited from his mother, a source said "legacy and celebrating the Queen" would be one of the guiding principles.
Balmoral is currently running on a special schedule reflecting the Queen's death. It will be open to the public from October to December with no admission fees, with no guided tours of admittance to the castle itself "as a mark of respect".
A spokesman said: "Visitors will be able to visit the grounds and gardens, where they can enjoy the peace and tranquillity of this special place and pay their respects to Queen Elizabeth II."