The Worst Stone ever used in the Metropolis: 150 years of Stone Decay in the Houses of Parliament

London’s House’s of Parliament are currently in dire need of restoration and repair. This iconic building is coming apart at the seams due to heavy usage, and quite frankly, inappropriate choice of building materials by men who should have know better 150 years ago. The stone is, of course not the only problem faced by this building; large amounts of asbestos panelling and insulation were installed in the post war period and the whole place desperately needs rewiring. The big decision the government needs to make at the moment, is whether to allow the repairs to go on with minimum disruption to the day-to-day business or to move everyone out for 6 years and turn the building over to the contractors. The first option is estimated to cost £5.7bn and take up to 32 years. The six year plan would probably cost in the region of £3.5 bn. This option sounds like a no brainer, but where would Parliament sit in the meantime?


Following the destruction, by fire in 1834, of part of the Palace of Westminster, Prime Minister Robert Peel launched a competition for architects to submit plans for a new seat of British Government in the ‘Gothic or Elizabethan’ style. Charles Barry, in collaboration with Augustus Pugin submitted the winning design. So far so good. The plans were for a superb Gothic palace to sit on the banks of the Thames. Barry’s costing may also have been influential, as he was determined to do this job on the cheap and as quickly as possible. Nevertheless, he contracted the most eminent geologists of the day, Henry de la Beche and William Smith along with master mason Charles Harriot Smith for assistance in selecting the stone (Lott & Richardson, 1997). This team were subsequently known as the ‘Special Commissioners’.

The ensuing cock-up is a well-known story, and the history of the debacle has been described by Lott & Richardson (1997) and Anon (2003). To summarise, a shortlist of suitable freestones were identified. They were: Portland Stone, Darley Dale Sandstone, Bolsover Stone and Anston Stone. The obvious choice in retrospect, and even at the time, would have been Portland Stone, because this had had widespread use in London for the last two centuries and was clearly bearing up well to the smog and pollution, as testified by the good state of repair of buildings such as St Paul’s Cathedral and numerous other churches. But no. The building stone dream team decided to go for Bolsover Stone, on the grounds that it had ‘advantage of colour’ and strong evidence of its durability as demonstrated by its use in Southwell Church (now Southwell Minster) in relatively unpolluted Nottinghamshire.

It should be noted here that Southwell Minster is in fact built from Mansfield White Stone (Thomas, 2006; Lott & Richardson, 1997).

However on investigation of quarry at Bolsover Moor, it was discovered that the quarry was far too small to furnish the stone, and the stone was of poor quality. Disaster averted?

Both Bolsover and Anston Stone are derived from the Permian Cadeby Formation of dolomites which outcrop from Nottinghamshire to Sunderland in an approximately N-S trending band. Many excellent stones are derived from the dolomitic limestones, but there is considerable variation in facies, texture and durability along strike. Once set on the Magnesian Limestone (as the Cadeby Formation was then known), the Special Commissioners opted for Mansfield Woodhouse Stone and, predominantly, Anston Stone as second choice, and stone started being quarried from these localities for the construction of the Houses of Parliament. The stone was transported to London via barge to the Humber Estuary, then down the east coast to London (Lott & Richardson, 1997).

The building was constructed between 1840 and 1859. It quickly became clear that disaster had indeed not been averted and that the Anston began to decay in London’s polluted atmosphere as soon as it was laid. But to quote John Allen Howe (Howe, 2010) ‘The bad state of the dolomitic limestone in the Houses of Parliament does not prove that stones of this class are worse than other limestones for town use, but that slovenly work will produce the results to be expected of it.

Howe and his colleague James Elsden further elaborated on the levels of slovenliness employed in the Anston Quarries (Elsden & Howe, 1923, quoting a Report of the Government Select Committee on the subject, recorded in Cowper, 1861). Despite most of the stone at Anston being of good quality, there are a number of beds that were known to be poor. But the beds were ‘worked indiscriminately’ and good strata were not followed laterally. Also ‘no supervision of the quarries was provided for and no seasoning of the stone took place. The stone was sent to London within a fortnight of quarrying, even throughout the Winter.’ Soft limestones and dolomites such as these are normally left out to cure in the air for several months before being used. Speed and volume seemed to be of the essence, quantity outstripping quality; ‘So little stone was rejected at the quarries that almost the only waste was that derived from the cutting of the blocks’. Therefore stone of exceedingly poor quality was used along with very sound stone.

Once in London and in the hands of the builders, it was discovered that the stone had not been marked, therefore it was not quarry-laid, i.e. in its strongest orientation. Much of the aslars ‘were sur-bedded – an example of unpardonable slackness’ (Elsden & Howe, 1923).

The author Charles Dickens has already waded in on the subject of ‘unpardonable slackness’ in 1860, writing in a periodical that the Anston Stone used was ‘the worst ever used in the Metropolis’.

Elsden & Howe (1923) write that Anston Stone was used in the whole building except ‘the upper part of the towers and the front towards Abingdon Street’. Tantalisingly, they do not say which stone was used here, though these authors do say that Steetly Stone (also from the Cadeby Formation) from near Worksop was used to a ‘small extent’.


By the 1920s, several blocks of stone had fallen off the building, so much so that members of the Terrace Bar were recommended to sit as close to the river (and as far from the building) as possible to avoid being hit by falling masonry (Anon, 2003). Around 200 tones of stone were removed and replaced in the 1920s. It was commented in the 1960s that the Houses of Parliament resembled ‘Joseph’s multicoloured coat’. A major programme of works cleaning, repointing, replacing and carving stone happened during the 1980s and 90s, using Clipsham Stone and French Anstrude Stone (Anon., 2003). The latter stone is a Bathonian oolitic limestone from Bierry-des-Belles-Fontaines in Burgundy. It came into use when supply of Clipsham Stone could not keep up with demand. Incidentally, this is the stone that was used in the controversial restoration of the British Museum in the late 1990s.

It is difficult to get close enough to much of the Houses of Parliament these days, for obvious security reasons, however one can examine close-up the grand Peers’ Entrance on Abingdon Street. Certainly a golden yellow stone is used here. The foundations and stone used for the arch are paler than the upper yellow stone, and is a coarse grained calcarenite, cross-bedded and packed with ooids, peloids and shell fragments. It is Clipsham Stone, from the middle Jurassic Inferior Oolite Formation. Running repairs have continued at the Palace of Westminster over the last century and a half. Clipsham Stone has been used since 1928, extracted from Medwells Quarry in Rutland (Anon, 2003).


Above: Clipsham Stone at the Peers’ Entrance

William Smith died in 1839 and therefore did not have to suffer the relentless criticism for the poor choice of stone. The full blame cannot be laid at the feet of either Smith or De la Beche, the fault was clearly with the (lack of) quarrymasters and subsequently cutting corners with stone production. The consequences are, nevertheless, that British taxpayers will have to fork out £3-5 bn bill in the 21st Century. Henry de la Beche went on to redeem himself and Anston Stone by choosing this material to build his Museum of Practical Geology on Jermyn Street. However, De la Beche took care in this instance to supervise quarrying and inspect the stone used. This building has subsequently been demolished, so we cannot comment today on whether or not he chose wisely.

The moral of this story is #shouldhaveusedPortlandStone

References & Further Reading

Anon, 2003, (revised 2010), House of Commons Information Office., Restoration of the Palace of Westminster: 1981-94. Factsheet G12 General Series:

BBC News: Parliament restoration plan could cost up to £5.7bn;

Cowper, W., 1861. Report of the Committee on the Decay of the Stone of the New Palace at Westminster.

Dickens, C. 1860. All the Year Round. November Issue. Chapman and Hall.

Elsden, J. V. & Howe, J. A., 1923, The Stones of London., Colliery Guardian, London., p. 132-133.

Houses of Parliament Restoration and Renewal;

Lott, G. K. & Richardson, C., 1997, Yorkshire stone for building the Houses of Parliament (1839-C.1852)., Proceedings to the Yorkshire Geological Society., 51 (4), 265-272.

Restoration & renewal of the Palace of Westminster;

Thomas, I., 2006, Southwell Minster., Mercian Geologist, 16 (3), 220-222.