The historic significance of the medieval complex - comprising one of England’s premier abbeys, a college of canons, and a royal palace, the usual meeting place of Parliament and the Courts and the main seat of Government - cannot be over-estimated, though one doubts that its historically integrated nature is apparent to visitors standing in Parliament Square. The Westminster World Heritage Site and Parliament Square, with the Palace, Westminster Abbey, the Supreme Court, and the buildings of Whitehall, are at the heart of the history of the British constitution; but the Square has become a polluted, congested, inaccessible and unwelcoming roundabout. UNESCO has expressed concern about the amount of traffic and pollution, though the boundaries of the World Heritage Site have not yet been extended to include the Square, despite UNESCO’s promptings.

Then-Mayor Ken Livingston sought partial pedestrianisation of the Square, but his plan was dropped under his successor. In 2011 the Hansard Society published ‘A Place for People: A New Vision for Parliament Square’, which pointed out that the surrounding buildings, representing Parliament, Religion, the Judiciary, and Government, made the square the heart of the nation’s constitution and told its history. It argued that with pedestrianisation the square could become a place for public engagement with talks and events, and where people would be informed of the complex history of the constitution and of the buildings in the whole area. Although north and east of the abbey only Westminster Hall and St Mary Undercroft (drastically remodelled) and part of the cloisters survive, there is abundant graphical, survey, and - increasingly - archaeological evidence to allow the lost structures to be reconstructed on paper and by computer modelling.

Reconstruction of the Lesser Hall from NW derived from survey and graphical evidence. Medieval Palace of Westminster Research Project.

Public interest could also be stimulated by a programme of archaeology. There is rich archaeological potential in Victoria Tower Gardens, site of the medieval abbey mill, and future site of the Holocaust Memorial Gardens. Although the construction of the present Houses of Parliament on a thick concrete raft destroyed much archaeological evidence for the eastern part of the site, other areas still have great archaeological potential - as was amply demonstrated during the New Palace Yard works in 1973, when the underground car park was created and the remains of a magnificent medieval fountain found. The site of the Lesser Hall, which remained standing until 1848 while the new palace was going up to the east of it, is under Old Palace Yard. An excavation here would almost certainly reveal the footings of the hall and, deeper still, possibly Edward the Confessor’s royal palace.

Lessons must be learnt from the mistakes of the past, and the current failure to undertake a serious archaeological investigation while the roof of Westminster Hall is cleaned and repaired. When it was repaired by Frank Baines in 1914–23, meticulous record drawings both of the roof and the associated historic masonry were made, but the roof is still not properly understood and today there are techniques unknown in the 1920s such as tree-ring dating. Full recording would normally be a planning condition of works to any listed building, let alone the finest medieval roof in the world; but to almost all experts’ surprise and despite much discussion, this is not being done. To avoid a similar mistake, before any contract for work on Restoration and Renewal is agreed, an assessment must be made of the archaeological potential of the Palace, and this must mean involving the Government’s expert body, Historic England, at an early stage. A lack of consultation could lead to such simple errors as using Old Palace Yard as a storage depot, making archaeological investigation of the area impossible.

The debate about Restoration and Renewal has so far been narrowly focused on the Victorian Palace, cost, and the pros and cons of the various options for temporarily removing MPs and peers from the estate. But there is an opportunity to take a wider view of the whole of what might be called the wider World Heritage Site, which must involve consulting and giving full weight to the views of all significant parties, including UNESCO and Historic England. The appalling terrorist attack in March 2017 has also meant that the whole site has to be considered and added a security dimension to the already powerful case for pedestrianisation.

The Westminster World Heritage Site and Parliament Square could be one of the world’s greatest public spaces, providing a wonderful, welcoming setting for the public: a place to enjoy and reflect on our history. The creation of a great public space and an examination of the rich archaeological potential of the site need not add to delays, and any costs will be minimal compared with the Restoration and Renewal project. If the country is going to spend billions of pounds on this project, there have to be wide public benefits.

Banner image: Engraving (artist unknown). ‘A view from the River Thames of the Parliament House, Westminster Hall, and the Abby’, c.1725. Medieval Palace of Westminster Research Project MPW 601.