Mouldy houses - building science lessons from the Wallaceburg Project.

Thirty-nine houses with high levels of biologically active contaminants in Wallace burg, Canada, and twenty houses with low levels of biologically active contaminants, were subjected to field inspections and testing, monitoring of indoor environmental conditions, and simulation to predict the condensation formation potential in winter. Occupant health was evaluated through questionnaires and blood sampling from an index child (closest to age ten) for analyses of T-lymphocyte and B-lymphocyte structure. We found that low air leakage and natural ventilation were not associated with higher measures of mold growth. Analyses found that moisture sources in the houses were a more significant factor in mold and dust mite antigen levels than relative humidity. Visible mold area was not a good predictor of ergosterol concentrations, indicating that hidden mold growth may be a factor. This paper addresses the influence of house and construction characteristics on the levels of mold growth and the building science lessons provided by this project.