Wytham Estate Manor House was built around 150 years ago. As part of the building renovation process, the clay walls were stripped of their old plasters and underwent minor repair work using steel mesh and lime plaster. In order to enhance the breathability of this heritage building system, our team utilised airPLAST lime plasters to plaster all internal walls. We also applied airCOAT, a lime-based paint, to maintain the breathability of the system. Through this project, we learned that cement should not be used in a heritage breathable system, not even for patching purposes.