All your questions about the Elizabeth Tower and Big Ben works answered

Frequently asked questions about the conservation of the Elizabeth Tower and Big Ben.

To ensure that the UK’s most famous clock continues to keep time, specialist teams carry out regular maintenance and adjustments to the Great Clock. However, the Elizabeth Tower is suffering from problems common in buildings of a similar age. The last time significant work was carried out to the Victorian Tower was in 1983-85. The conservation works will:

  • Repair problems identified with the Elizabeth Tower and the Great Clock, which cannot be rectified whilst the clock is in action.
  • Conserve significant elements of the Tower, as designed by Charles Barry and Augustus Welby Pugin.
  • Repair and redecorate the interior, renew the building services and make improvements to health and safety and fire protection systems.
  • Improve energy efficiency to reduce the Tower's environmental impact.
  • In order to provide a better means of emergency evacuation, and to improve accessibility for a wider range of people, a lift will be installed within the existing ventilation shaft of the Tower.

The last significant conservation work was completed in 1983-85. This involved the cleaning and repair of the stone, painting and gilding works and repairs to the cast iron roof. The structure was stabilised in 1995/96 as a result of works carried out to the Jubilee Line. Parts of the clock mechanism were serviced in 2007, but other areas haven’t been overhauled in over 25 years.

There is a risk that the clock mechanism may fail or that long term fabric degradation to the building will occur.

This project was agreed by the Commons Administration Committee on 12 October 2015, the Administration and Works Committee in the House of Lords on the 2 November 2015 and the Commons Finance Committee on 14 October 2015 and 4 November 2015. The revised costings were noted by the House of Commons and House of Lords Commissions on 6 and 13 September 2017 respectively.

Much of the work is straightforward repair but any alterations or additions will be subject to listed building consent granted by Westminster City Council in consultation with Historic England.

The last time significant work was carried out to the Tower was in 1983-85. The current proposals will address the overdue maintenance of the Tower and prevent further decay. As with other buildings of the same age, future maintenance will be required in order for this iconic building to remain in good condition and to safeguard it for future generations.

We are undertaking key internal and external conservation and refurbishment works, including waterproofing and addressing severe condensation problems as well as modernising the building to improve standards in safety, access and visitor and workspace facilities. The project includes:

  • Work to prevent the clock mechanism from failing, as it is currently in a chronic state.
  • Addressing urgent problems caused by decay to the fabric of the building, both internally and externally.
  • Health & safety and fire safety improvements, including installation of a lift.
  • Enhanced energy efficiency through modern lighting of the tower face and other measures.

Overall the project’s aim is to repair and conserve the Tower, upgrade facilities as necessary and to ensure its integrity for future generations.

The contract for the work has been awarded to Sir Robert McAlpine Ltd. The Pre-Construction Service Agreement and the scaffolding contract were previously awarded to Sir Robert McAlpine in November 2016. The clock mechanism repairs will be carried out by our internal team where possible.

Work began in early 2017.

The programme of works is expected to complete by 2021.

The total budget for the project, including VAT, risk, contingency and optimism bias is £79.7m.

Further information

The money to fund this project is coming from the Medium Term Investment Plan of the Parliamentary Estates.

A range of options were considered, taking into account benefits, ongoing cost and capital costs. The option offering best value for money and the most benefits to the public and to Parliament was chosen as the recommended option.

Yes. Specialist scaffolding is required in order to provide access to the external parts of the Tower. We will aim to ensure that one working clock dials is visible for as long as possible during the works.

The scaffolding will be visible for the duration of the project but the upper section of the Tower will be uncovered as the project progresses.

It will be necessary to cover the clock dials whilst carrying out repair work and maintenance to the glass, and metalwork, and whilst removing the hands. We will aim to cover the dials in succession, each one for as short a time as possible. Throughout the project we will aim to ensure at least one working clock face is visible.

On Monday 21 August 2017 following the 12 noon chimes Big Ben’s bongs temporarily ceased. While vital restoration work takes place, the Great Bell’s world famous striking and chiming was paused until 2021 to ensure the safety of those working in the Tower. Parliament’s specialist clock mechanics will ensure that Big Ben can still bong for important national events such as New Year’s Eve and Remembrance Sunday.

The bells did not chime for a period of around nine months when the clock underwent a major overhaul in 1976. Significant conservation work was carried out between 1983 – 5, and the bells were silenced for a time during this period. In 2007 the bells were stopped for a period of 6 weeks, whilst essential maintenance works were carried out.

Yes. One working clock face will be visible throughout the works, the hands of  which will be driven by an electric motor. However, the clock mechanism itself will be stopped at times during the works in order to repair the hands, bearings, gears and drive mechanism. 

The clock mechanism was dismantled in early 2018 and removed for conservation work. However, one working clock face will be visible throughout the works, the hands of which are driven by an electric motor.

The Ayrton light has been removed for repair, and a substitute light has been installed whilse the work is carried out.

One of the aims of the project has always been to conserve the Victorian Tower, as originally designed by architects Charles Barry and Augustus Welby Pugin. Extensive historical research by the Architecture and Heritage team in Strategic Estates at Parliament, as well as expert paint analysis, revealed the original colour scheme of the clock face, which over time had been transformed by pollution and overpainting.

The Great Clock’s hands and the surfaces of the cast iron frame have now been stripped clean and repainted in a deep Prussian blue. The stonework has also been stripped of black paint, and the corners of the dial painted a vibrant Cobalt blue, with an extensive application of gold leaf. Temporary clock hands have been attached in place of the originals, which are undergoing conservation along with the rest of the Victorian clock mechanism.

324 pieces of glass in the North Dial were removed as part of the conservation, and replaced with new, expertly made pot-opal glass to match the Victorian original.

The former black and gold paint around the clock dials was applied in the 1930s.

Further information:

No. All works have been planned and designed with collaboration and input from the Parliamentary Security Department.

The scope of the project includes replacing the flood lighting infrastructure so there may be a period of time when the Elizabeth Tower cannot be lit. The project team will work with the contractor to minimise the period of time that the Tower is not lit.

There is a risk that the clock mechanism may fail, also if concerns about the fabric of the tower are not addressed now it may lead to further more serious damage to the tower in the future.

Elizabeth Tower is 96 metres tall. At clock face level – that is 55 metres above ground level – it is out of plumb (i.e. does lean,) by 220 millimetres towards the northwest. This results in an inclination of about 1/250 (0.2 degrees), making it just about discernible to the casual onlooker. Natural settlement and work to both the underground car park and the Jubilee Line tunnels have contributed to the lean. While the lean does not present any concerns, monitoring does take place on a regular basis.

At present there is only a single spiral staircase with 334 steps. Emergency evacuation from the Tower is currently carried out using a complex abseiling rig. To improve safety and to help reduce the time it takes to evacuate an injured person from the Tower in the event of an emergency, a lift will be installed in one of the existing ventilation shafts. The lift will also provide improved access (though not full access due to constraints of the space) for some disabled people who are currently unable to use the stairs, and will improve access to the clock for maintenance purposes. It will have no impact on the external appearance.

No. Part of the visitor experience of the Tower is climbing the 334 steps and the installation of a lift is not intended to change this. However, the lift will provide improved access (though not full access due to constraints of the space) for some disabled people who are currently unable to use the stairs. The lift will also reduce the time it takes to evacuate an injured person from the Tower in the event of an emergency. In addition, it will improve both security and access to the clock for maintenance purposes. The lift will be installed inside one of the existing shafts in the Tower and will have no impact on its external appearance.

No. The lift is being carefully designed to ensure the safety of passengers, whilst at the same time having no impact on the structural integrity of the building.

No. The lift will be installed inside one of the existing shafts in the Tower and will have no impact on its external appearance.

Yes. During the works, it will not be possible to run tours of the Elizabeth Tower. Tours will be suspended for the full duration of the project. Final tours took place in December 2016.

It is anticipated that tours will resume once the works have been completed.

Tours of the Elizabeth Tower are available free of charge to UK residents and British Citizens. They must be booked via your local MP or a Member of the House of Lords. Further information is available on the website. To accommodate these renovation works, tours were suspended from December 2016.

These are essential repair works and are not intended to increase the capacity of the Tower to host tours. However, they will improve the visitor experience and make the running of the Tower easier for both maintenance and Tower staff.

There are currently no plans to start charging for tours. This would be a decision for MPs.

The Elizabeth Tower conservation project is not part of the wider Palace of Westminster Restoration and Renewal Programme. The feasibility study of the Tower showed that this work cannot be delayed and it now requires urgent attention. If this work is not undertaken, there is a risk that the clock mechanism will fail, and that significant damage will happen to the fabric of the building.

In addition, Regulatory Reform Order 2005 (RRO) requires Parliament to comply with current fire safety requirements by 2018. At present, the Elizabeth Tower is not compliant and alterations must be made to meet these requirements. There are also a number of workplace health and safety risks which must be addressed in order to ensure the safety of those working in the Tower, or visiting it. This includes implementing a solution to ensure that in the event of an emergency, a casualty could be evacuated from the Tower as quickly as possible.

We do not anticipate the Restoration and Renewal of the Palace having any impact on the Elizabeth Tower directly, and our aim is that the clock will remain fully functional.

Image: Parliamentary Copyright