Foundry terrace in Llanidloes Mid Wales was constructed in the 1860’s by the owners of the foundry to house their workforce. These small cottages in a terrace are fine examples of 19th century cottages of their type and age. The foundry site is still alongside today but closed many years ago. The terrace is a grade 2 listed building and now in the ownership of Powys County Council. Like many buildings of their age they have been retrofitted and treated with impermeable materials. Edwards Hart were commissioned to undertake a full survey and building pathological analysis. This has examined the hygrothermal performance as well as condition and have provided options on how to make improvements with full consideration of historical significance values.