Anston Stone and the Houses of Parliament

Written by Dr Ben Winpenny, Department of Earth Sciences, University of Cambridge

Anston Stone, quarried in South Yorkshire from Permian dolomitic limestones of the Cadeby Formation, has, perhaps unfairly, gained a reputation as a poor building stone. Its use in London for much of the construction of the new Palace of Westminster (the ‘Houses of Parliament’) in the mid-19th century has led to nearly two centuries of problems requiring expensive remediation.

Problems became apparent with the choice of Anston Stone for the Palace of Westminster as early as 1849, only a few years after construction had begun. The stone, chosen for its ability to be ornately carved and relatively low cost, soon began to decay in the city’s polluted atmosphere. Two eminent geologists of the day, William ‘Strata’ Smith and Henry de la Beche, were criticised for their part in choosing Anston Stone. The problems became widely known: an 1860 issue of Charles Dickens’s periodical ‘All the Year Round’ stated that the stone “proves to be among the worst ever used in the metropolis’. 

But decay from pollution was not the only cause of the problems. It was determined that a lack of supervision during quarrying had led to stone being “quarried and delivered indiscriminately, without regard to the nature of the bed, the lie of the rock in the quarry, or the necessary seasoning of the stone”. At least some of the impact of this careless work could have been prevented: the master mason who was also involved in the stone selection had offered to inspect the blocks of stone at the quarry, provided he was paid £150 a year. But this offer had not been accepted, because of uncertainty about whether the Office of Works or the architect was responsible for his fee.  Had this “unimportant amount” been agreed upon, perhaps the huge bill to the public purse for remediation work over the past century and a half could have been significantly lower.

Despite many lengthy and expensive interventions over the years, including using other stones such as Clipsham stone (which is on display at the Sedgwick Museum), problems remain with the crumbling stonework. The proposed Houses of Parliament Restoration and Renewal Programme notes that 19 “stonemasonry incidents”, including falling lumps of masonry, have occurred since 2016, and more remedial work is required. The problems, and the associated expenses, continue.