The work on the oldest part of the Grade II-listed building on Millbank was done by architects Caruso St John, taking three years. "We haven't lost anything we loved about this building," Curtis said. "We've peeled away the accretions and taken it back to the simplicity."
The changes follow another major overhaul this year, with the reconstruction of 10 galleries and a rehang of the collection of British art in chronological order. Tate director Sir Nicholas Serota called it an "exciting day" and said the history of the venue was one of expansion and renewal.
"Between 1960 and 1990 people felt apologetic about this building. They felt they needed to reduce the heights of ceilings and introduce false walls," he said. "With accretions and layers of paint we had become rather blunted and almost municipal in character." Referencing criticism from the 1940s and 1950s that the building had no distinctive qualities, Serota said: "Now it does."
One of the biggest changes to the design is a striking new spiral staircase inside the entrance leading to new public spaces on the floor below. The spaces below include the Archives Gallery, which will house temporary displays from the Tate's huge vaults. Among the documents on display are plans for the prison that was on the site before the gallery - as well as a note from plasterers hidden in the original building in 1897.
The Tate was designed by architect Sidney Smith, and opened its doors to the public in 1897 with 245 works in eight rooms.
Following the renovations, Curtis said they had discovered Smith was "perhaps a better architect than many people had realised".
The team working on the three-year revamp has opened the circular balcony in the domed atrium for members and has created a grand saloon for functions. This space has been closed since the flood of 1928, when the Thames broke its banks and flowed into the gallery.
Private donations paid for about 95 per cent of the renovations, with the rest being made up by the Heritage Lottery Fund. Tate chairman Lord Browne said this marked a "triumph for private philanthropy".
Serota said visitors would now experience the building "in ways they had not done in the past".
He added that "the whole experience of coming to Millbank will be changed from simply looking at pictures to an environment that is stimulating to be within. That's what Henry Tate originally wanted."
- Independent