Hugh MacDiarmid is acknowledged as the central figure in the nation’s literary renaissance during the first half of the 20th century.
MacDiarmid, best known as a poet and political commentator, lived there for 27 years until his death, aged 86, in 1978.
Now urgent work is needed to upgrade Brownsbank Cottage so it can be retained for visitors and as a residence for up and coming Scottish writers.
The Class A listed building has lain untouched since the death of the writer's widow, Valda Trevlyn, in 1989.
In a report outlining refurbishment plans, LDN Architects said: "The restoration project is a critical moment in the life of the cottage.
"It is full of furniture, art and personal objects belonging to Hugh MacDiarmid which are at risk of damage if conditions are not improved.
"The building is unique due to its association with MacDiarmid and forms a fascinating part of Scotland' s history."
MacDiarmid's Brownsbank Trust, which is appealing for public donations, says a six-figure sum is needed for "urgent" work to make the rain-damaged cottage habitable again.
It is intended to reopen to visitors and provide accommodation for writers in residence.
A number of Scottish authors and poets were in residence at Brownsbank until 2011.
Trust chairman Denham Macdougall said: "As well as the refurbishment, this is about raising awareness of MacDiarmid's work and re-establishing the writer in residence position with an eye on contemporary Scottish literature."
Author James Robertson, a former writer in residence at Brownsbank, is backing the fundraising campaign.
He said: "Hugh MacDiarmid was my great literary hero.
"Brownsbank changed my life. It allowed me to give up full time employment and begin to make a living as a writer.
"That wouldn't have happened without my two years at Brownsbank."
The trust has now applied to South Lanarkshire Council for planning permission to carry out repairs.
It hopes to begin work in the summer and have the cottage habitable early next year.
The restoration project has already received funding from SSE Clyde Windfarm Fund, Architectural Heritage Fund and William Grant Foundation.