A team of experts who were hired to assess the fabric of the Houses of Parliament have found crumbling stones, cracking ceilings and warped and sagging stained glass windows in the 181-year-old building.
They spent thousands of hours examining 2,343 rooms and spaces in the Palace of Westminster during the summer recess and the three weeks of the party conference season.
Their report lists thousands of cracks in stonework, widespread water damage and millions of pounds’ worth of work needed to update electrical, mechanical and drainage systems.
The leader of the House of Commons, Jacob Rees-Mogg, said: “The Houses of Parliament building is recognised the world over as a symbol of our nation, but this building requires a considerable level of care to keep it working and needs an essential programme of restoration work.”
Mr Rees-Mogg said: “We must be able to justify this project to taxpayers. That's why it’s so important to understand and map out the restoration work needed to protect the building - so that the focus is on those essential works necessary to preserve the Palace for future generations.”
The Palace of Westminster has housed the British Parliament since 1707 and was home to a form of democracy in England since 1295.
A sketch of the Ladies' Tea Rooms in the Palace of Westminster
© Photo : Houses of Parliament / Ladies' Tea Rooms
Among the quirks of the building are candle and gas light fittings, which were turned upside down when Parliament got electric power more than 100 years ago.
The Palace also contains what may be the oldest gas lighting system still in use anywhere in the world.
In 2015, a report by Deloitte Real Estate estimated the cost of the refurbishment work at £3.5 billion if MPs and peers vacated the building for six years and said the alternative of builders fitting in with the Parliamentary timetable would mean the work taking 32 years and costing £5.7 billion.
But in January this year Meg Hillier, the chair of the House of Commons public accounts committee, estimated the true cost could be closer to £12 billion.
SNP MP Pete Wishart said described the estimated cost of the work as "eye-watering."
In 2018, MPs voted by 236 to 220 to decant from the Palace of Westminster during the refurbishment, although the earliest they would move out would be 2025.
A workman taking measurements in the House of Lords' chamber of the Palace of Westminster
© Photo : Houses of Parliament / Workman in House of Lords
The then-Leader of the Commons, Andrea Leadsom, said they could not "patch and mend" any longer.
Mrs Leadsom said the building faced "critical risks" and there had been 60 occasions in recent years where a serious fire almost broke out due to its antiquated electrical wiring.
Among the places mentioned as a temporary home for Parliament during the repair work is Richmond House, a building in Whitehall which currently houses the Department of Health, or the Queen Elizabeth II Conference Centre.
The Houses of Parliament has undergone a massive structural assessment survey
© Photo : Houses of Parliament / Man checks door at Palace of Westminster
With mounting speculation over the size of the job Parliament hired 50 engineers, architectural surveyors, acoustics and lighting specialists, and ecologists to pore over the Palace of Westminster and come up with the most comprehensive report in its history.
More survey work will be done over the winter and MPs and peers will eventually vote on a detailed restoration plan in 2023.
Sarah Johnson, CEO of the Houses of Parliament Restoration and Renewal Sponsor Body, said: “The essential programme to restore the deteriorating Palace of Westminster will protect our world-famous Parliament for generations to come. These critical and complex investigations are already informing our detailed restoration plan, which will for the first time set out a true sense of the costs and timescales of the much-needed work.”