Financier Dermot Desmond has secured planning permission from An Bord Pleanála to carry out works on a property at Merrion Square in Dublin.
The board had refused permission in 2003, but Mr Desmond took a successful High Court action to quash the decision.
It is understood the proposal was passed on the casting vote of An Bord Pleanála's Chairman, John O'Connor, after members were evenly split five votes to five. The planning inspector's report had recommended granting permission.
In July 2002, Dublin City Council had refused permission for the development, which comprises retention and completion of a dumb waiter and electrical riser at basement, ground, first, second and third floor.
An appeal taken by Illium Properties Limited, on behalf of Mr Desmond, has now been upheld by An Bord Pleanála, subject to one condition, in part because the changes would be entirely reversible.
