Old Pattern Shop

The Old Pattern Shop is a derelict building that dates from the late 18th century to the early 19th century. It features lime-washed shale rubble walls, some brick, slate sills, and timber lintels. The roof is made of grouted scantle slate with gable ends, although some of the roofing has fallen. The building has a long rectangular plan that was originally undivided. In the 19th century, a lean-to straw rope shed was added along the north side.

The structure is two storeys high, with the south side displaying a slightly irregular arrangement of openings, featuring nine openings on each floor. There is a first-floor loading doorway with a pair of ledged doors that is accessed by an earth ramp. Most of the windows, which have vertical glazing bars, are still present, although many have broken panes. The north side has a similar arrangement of openings and windows.

The interior has not been inspected but is reported to be unaltered since the 19th century. The Old Pattern Shop was part of the Perran Iron Foundry, which was established in 1791 and became the most significant foundry in Cornwall, known for manufacturing some of the largest beam engines ever built. Much of the original fabric and features are still intact, but the building was derelict at the time of the survey in 1985.