Thomas Pritchard suggested building the iron building to the ironmaster, John Wilkinson, in 1773. Prithchard drew up the designs, but he died in 1777 which was a month after the work had begun. Later Abraham Darby the third agreed to finish the project. The construction was completed in 1779,using 378 tons of iron. It was officially opened on New Years Day in 1781. It costed over $9,300.