Repairs are to be carried out on the listed home of poet Hedd Wyn to mark the 60th anniversary of Snowdonia National Park.
A new roof will be installed at Yr Ysgwrn, Trawsfynydd, which is open to the public as a memorial to the bard who died in World War I.
He was posthumously awarded the chair at the Birkenhead Eisteddfod in 1917.
The ceremony was held with a black cloth covering the chair, which the park has named one of its 60 wonders.
Work is scheduled to being on Monday and to take four months.
About 3,000 people a year visit the house, where the chair is kept .
Records show the farmhouse, which is east of Trawsfynydd, dates back to before 1849 and is listed as Grade 11*.
Emyr Williams, Snowdonia National Park Authority's director of land management, said: "It has been on the list of endangered buildings for some time... it's wonderful that we as an authority, with substantial financial support from Cadw, can safeguard the roof of this significant building".
A tent will be placed over the building to protect the inside of the house while the old structure is removed and the new roof is built.
The poet's nephew, Gerald Williams, who owns the building, said he was grateful for the park authority's help, and that of Cadw, the body responsible for preserving ancient monuments in Wales.
"The condition of the roof has been a worry for me for some years," he added.
"It's going to be interesting seeing the tent covering the house when the men will be working on it."
During the work, the building will be closed to the public unless previous arrangements have been made.