Development of a performance indicator for mould growth risk avoidance in buildings

Microbial growth has been known as one of the major problems related to IAQ inresidential and commercial buildings. International and local standards define theupper limits of indoor relative humidity in order to avoid moisture related problems.However, setting limits on indoor relative humidity does not guarantee a mould-freeenvironment. The intention of this ongoing research is to develop a performanceindicator (PI) that can be used to monitor and test the performance of existingbuildings, in terms of the risk of fungal growth.This PI for mould growth risk should be based on a mix of building componentcharacteristics and usage factors as they implicitly determine mould growthconditions. The building components include building envelop systems, HVACcomponents, furniture, occupants and so on. This paper describes the development ofthe PI that is composed of five sub-elements (one for the physical states at interiorsurfaces and four for building situation factors). Each of them may be an aggregatedvalue, not just a measurable simple property.