[This article is not just patently ridiculous, it is just plain old STUPID!
That house and ground belong to the Dutchy of Cornwall and one MUST be a DUKE OF CORNWALL to own it!
Actually “own” isn’t really the correct word...it’s the Duke’s to LOOK AFTER!]
Cornwall is a Duchy, the land and building belong to the Duke of Cornwall, whomever that may be, and so, is CROWN PROPERTY.
It's not the same, but akin to claiming that King Charles III has sold BUCKINGHAM PALACE; which, of course, is an absurdity.