220 schools. Damage and defects in school buildings SP has investigated more than 220 school buildings between 1978 and 1997, finding damage in most of them. This report describes the damage and defects that we have found in building materials, functions, building services systems and structural parts of the buildings. The report also describes mechanical and biological mechanisms that have contributed to the damage. In general, most of the buildings have exhibited several defects, with the most noticeable damage being caused by moisture. The damage has been caused by defects, but the number and diversity of these defects is striking. The report describes our experience: the text is complemented by no less than 174 figures and diagrams. There are differences between them, with more than one defect being illustrated in many of them. Many different types of faults have been found in the buildings: in general, several faults taken together have led us to the damage that we found. To some extent, the report describes where the faults have occurred: we have found faults that can be ascribed to all stages of the building and use processes, and to all parties involved. Faults have manifested themselves as faults in one or more of the building's functions or features, with the main causes being found in three functions: moisture resistance, airtightness and air handling. These functions are interdependent and can exacerbate each other. Airtightness, for example, forms an important element of moisture resistance, while the contamination (mildew etc.) caused by moisture damage can find its way into the indoor air through air leaks in the building structure (airtightness failure), powered by pressure differences established by the ventilation system (air handling), if there is an air flow from the area of moisture damage.