LONDON (REUTERS,AFP) - Britain's Big Ben tower at the Houses of Parliament was more badly damaged by German bombs during World War II than originally thought, experts said on Thursday (Feb 13), as the bill for its restoration rose by nearly £20 million (S$35 million).
The 177-year-old tower has been swathed in scaffolding for the past three years as craftsmen refurbish its stonework and famous 12 tonne clock.
Being able to get close to the 96m tower has allowed them to spot other problems like damage caused by pollution and asbestos.
The House of Commons and House of Lords Commissions said they had been told that to restore the tower to its previous splendour, the budget would need to rise from £61.1 million to £79.7 million.
Mr Ian Ailles, director-general of the House of Commons, said the task of restoring the tower had been more complex than anticipated.
"With a 12m square footprint and a prime location right in the middle of a busy working Parliament, understanding the full extent of the damage to the tower was impossible until the scaffolding was up," he added.
Among other problems, bomb damage inflicted on the tower during the World War II had been found to be more extensive than first thought.
Although the tower survived Nazi bombing, its roof and dials were damaged in a May 1941 air raid which destroyed the main House of Commons chamber.
The work is to repair the clock faces and mechanism, cracks in the tower's masonry and corrosion in the roof, as well as to restore the edging around the clock faces to its original 19th-century colour.
A lift will also be installed as an alternative to the steps up the tower, and the lights illuminating the clock will be replaced by low-energy LEDs.
The latest refurbishment of the structure, during which its 13 tonne Big Ben bell has been largely silenced, is expected to be finished next year.
Work on the structure - renamed the Elizabeth Tower in 2012 - is separate from the planned full-scale restoration of the Palace of Westminster which has been estimated to cost £4 billion and is due to start in the mid-2020s.