Alexandra Palace's derelict offices will be revamped thanks to a £550,000 grant from Historic England.
The project is part of a full scale restoration for the Grade II listed north London venue.
Work on the North East Office Building will be the next phase of the East Wing restoration project.
The offices are next to the East Court where the building's Victorian theatre which re-opened in 2018.
CEO of Alexandra Park and Palace Charitable Trust, Emma Dagnes, thanked Historic England for a "significant grant in our 150th year.
She said: "The funding will start us on the journey to bring these spaces back for public benefit."
Madonna, Stormzy, Ed Sheeran and the Earthshot Prize have been hosted at the theatre since its 2018 opening, after it had been closed for 80 years.
The trust said the offices are the last remaining truly inaccessible area in the seven acre "People's Palace" site.
They date to 1875 when they were used to house the administrators office, a ticket office, porter facilities, costume room and the Palace's First Superintendent.
This part of the building was also used extensively as television studios by the BBC from 1935 to 1981.
Structural work will start in December and includes removing decayed brickwork and timber, storing historic roof lanterns and installing a new roof covering.
The project funding comes via Historic England's Heritage at Risk programme, which helps significant sites across England pursue restoration projects.
Historic England's chief executive, Duncan Wilson, said: "I've always loved Ally Pally and am delighted to hear that the 25th anniversary of our Heritage at Risk programme has coincided with the 150th anniversary of the Palace in such a fruitful way."
The palace was built in 1873 as a centre for recreation in leafy surroundings near Muswell Hill. It is now home to an ice rink as well as a theatre and gig venue.
