This research examined fungi commonly found in damp or water-damaged buildings, focusing on the Chaetomium family. The study revealed there are many more species of these fungi in indoor environments than previously known, with some capable of producing harmful substances that can affect human health. The research provides better ways to identify these fungi and understand their potential risks. Impacts on everyday life: – Helps identify harmful fungi that can grow in water-damaged buildings – Improves understanding of health risks from indoor fungal contamination – Assists in proper remediation of fungal contamination in buildings – Contributes to better indoor air quality assessment methods – Aids medical professionals in diagnosing fungal-related health issues