Brian O'Driscoll and Amy Huberman have finally been given permission to revamp their €1.8m home.
The high-profile couple were granted planning permission by the city council in June, but their neighbours lodged an appeal with An Bord Pleanala.
The former Ireland rugby captain and his actress wife will now extend the side and rear of their home in Rathmines.
They will also reconfigure the front wall and gate.
The couple bought the Victorian house for €1.8m in 2016, less than half the €4.3m the previous owners paid for the protected property in 2006.
The house is split into three flats, but Brian and Amy want to return it to a one-family home.
Neighbours on the exclusive tree-lined road in Rathmines wanted An Bord Pleanala to refuse planning permission for the extension, or at the very least restrict the extent of the development.
Consultant Brian O'Donnell had said that, in simple terms, the adjoining property was particularly vulnerable to excessive development.
However, in an An Bord Pleanala report seen by the Herald, it said "the proposed development would not seriously injure the residential amenities of the area or of property in the vicinity".
An Bord Pleanala also said the revamp "would not have a negative impact on the character and setting of a protected structure or the conservation area and would not endanger public safety by reason of traffic hazard".
"The proposed development would, therefore, be in accordance with the proper planning and sustainable development of the area," it said.
Brian and Amy plan to move a public parking space to make room for their new entrance.
An Bord Pleanala stipulated that the developer must contact the city council's area traffic engineer regarding alterations to the pay-and-display space.
"All works shall be carried out at the developer's own expense," it added.
A conservation expert needed to be appointed to ensure adequate protection of the building's "historic fabric", An Bord Pleanala said.
Brian and Amy married in 2010 and have two children together, daughter Sadie (4) and three-year-old son Billy.