ESB will replace its headquarters with a new building styled after the historic houses it bulldozed to make way for it.
The State-owned power company has finally revealed plans for the building - which it had refused to disclose in recent years - in the heart of Dublin's Georgian quarter.
The winning design for their replacement flagship offices, by Irish architects Grafton Architects and O'Mahony Pike Architects, bears a remarkable resemblance to the streetscape that was levelled to make way for the current building.
Three years ago, ESB refused to disclose shortlisted designs for the redevelopment of the Fitzwilliam Street site, citing a confidentially clause under EU procurement law.
The construction of the existing headquarters sparked protests by conservationists in the 1970s over the demolition of 16 Georgian houses.
But planning permission was granted and the historic homes were razed to the ground on what was Dublin's "Georgian Mile" - from Mount Street to Leeson Street.
In its place was erected a modern precast concrete facade, designed by Arthur Gibney and Sam Stephenson. ESB later opened a Georgian museum at Number 29, in which visitors can see what a house from the era might have looked like.
ESB said the latest design " re-interprets but at the same time respects the surrounding architectural heritage".
A spokesman added: "After careful consideration of the Georgian streetscape, the proposal is to deliver a building that is respectful to its history, sensitive to its surroundings and representative of its own time."
The power company said the redevelopment would pay for itself through energy and maintenance savings, income from renting out part of the expanded space and other savings.
An ''expert jury'' of six people - three ESB chiefs and three architects - shortlisted designs for the latest redevelopment of a ''world class headquarters and offices''.
Eight designs originally shortlisted in the contest were each awarded 30,000 euro, while the top three entries got an additional 30,000 euro each.
Plans to replace the front of the office block with a Georgian facade as a Millennium project a decade ago were scuppered because of problems due to floor levels.
Although ESB said the latest redevelopment would be self-financing, a spokesman said it was not possible to give an accurate cost.
The figure will be available when it applies for planning permission next year, with work expected to begin in 2016, according to the company.