The new owners of Lissadell House in Co Sligo, which opens to the public next week, are planning to spend €5 million on restoring the building to its original state over the next five years.
Barristers Mr Edward Walsh and his wife Ms Constance Cassidy also say they will convert part of the building into a shrine to Countess Markievicz and W.B. Yeats.
The couple have already paid €3.75 million for the estate and an additional €800,000 on buying much of the furniture and fittings.
Members of the public will get their first chance to see the house since the new owners moved in last December with their seven children aged from one to 11 years on Tuesday, June 1st.
Many of the 72 rooms will still be empty when the first visitors pay their €6 entrance fee.
However, rooms of main interest are already well on the way to resembling the state they were in when construction of the house was completed in 1833 for Sir Robert Gore-Booth, the fourth Baronet.
He had ordered London architect Francis Goodwin to design a dwelling "worthy of the status of his family".
The new occupants aim to recapture the splendour of those days.
"We want to restore the house to the state, or as near as possible, that Francis Goodwin designed. The idea is to take away nothing and to restore what was originally here, or would have been here," said Constance Cassidy.
Major restoration work has been under way in recent months. Magnificent gasoliers which lit the house with a supply from a gasometer a quarter of a mile away are being carefully restored, as are the tall columns in the great hall matching in colour the Siena marble of its famous fireplace.
Faded billiard room walls are to be re-covered in the same brilliant claret colours of the original paper. Mr David Skinner, an expert on the wallpapers of the Great Houses of Ireland, has been recruited for the task.
The 192-year-old organ in the Great Hall made by the Hull company in Dublin is being lovingly restored by a leading organ restorer, Dr Desmond Armstrong.
From June 1st visitors will be greeted close to the imperial staircase in the Inner Hall by receptionist Ms Angela Leonard from Ballinfull. They will then be taken on a guided tour by Ms Clare O'Gara from Strandhill, Co Sligo, and Ms Sue Gadsby from Dromahair, Co Leitrim. Both guides worked there for previous owner Sir Josslyn Gore-Booth.
One of the rooms on the itinerary for visitors is the bedroom where W.B. Yeats slept during his visits to Lissadell.
At present, the room contains just a single bed with modern duvet. But the family plans to turn it and an adjoining room into a shrine to Yeats.
They have already commissioned a sculpture of Yeats sitting, as he used to with the young Countess Markievicz and her poet sister Eva - on a bench facing the sea and with his back to the house. On either side will be one of his poems.
Still in Lissadell after 100 years is a sign of a touch of vandalism by the young Constance. One of the window-panes in the ante-room between the drawing room and dining room has graffiti scratched into it. Beneath the date "1898" is scratched Constance's signature, Con Gore Booth.
Beneath that, her sister Mabel wrote M G Booth.
According to Edward Walsh it could take up to five years before all of the work that is planned on the house is completed.
However he said he did not regret buying it, or refusing the advice of people who suggested he should turn the estate into a holiday park or build apartments on it.