A campaign has begun to get Grade I listed status for the former Surrey home of Sir Arthur Conan Doyle, the author behind Sherlock Holmes.
Sir Arthur Conan Doyle lived at Undershaw from 1897 to 1906
The Victorian Society has asked English Heritage to upgrade Undershaw from its current Grade II status.
The "urgent application" has been made because of moves by Undershaw's current owners to redevelop the building.
A second planning application is due to be lodged next week for Undershaw to be converted into separate homes.
A previous application for 13 dwellings at Undershaw was rejected by Waverley Borough Council on 8 May.
The new revised proposal is for fewer dwellings at the property, which was most recently used as a hotel.
Christopher Atkins, from RDA Architects, speaking on behalf of Undershaw's owners Fossway Ltd, said: "It might have been his [Conan Doyle's] home once, but it's been through a number of different versions since.
"If it's left alone it will fall to pieces.
"The developer's intention is to provide a number of houses within the existing building, and that will then provide the funding to enable it to be restored to its original position as far as possible."
But the Victorian Society, working with the Sherlock Holmes Society of London, wants to protect Undershaw's heritage by ensuring it is safe from development.
It has requested Grade I listed status because "any scheme for subdivision could be hugely damaging".
Dr Kathryn Ferry, an architectural adviser with the Victorian Society, said: "This house has local, national and international significance as the home of one of the best-known authors in the English language."
The society said Conan Doyle commissioned Undershaw in 1896, living there for almost 10 years during which time he wrote such classics as The Hound of the Baskervilles.