This was the last remaining industrial building of the former Ivor Iron Works from the pre-British Steel period. The Ivor Iron Works opened in 1839 as an extension to the Dowlais Iron Works, initially with four blast furnaces. British Steel operated a foundry from the mid C20 which closed in 1987. This building was possibly built as a blast engine house but is more probably the sulphate of ammonia plant completed in 1928, as part of the coke and by-product plants constructed 1922-28. Sulphate of ammonia was one of the by-products of coke production, crude benzyl and tar being others. The building was converted some time between 1930 and 1949 to a general and electrical stores. It is red brick with slate eaves roofs and there are two sections both of two-storeys.

Source:- Cadw listed buildings ( NJR 04/03/2008)