Problems with schools' indoor-air quality are common, and they can cause health problems to adolescents. However, no previous research has examined how adolescents make sense of such contaminated socio-material environments or what kinds of agency those environments afford. Taking an ecological psychology perspective informed by frame analysis, we analysed longitudinal focus group interviews with adolescents in a Finnish school with longstanding indoor-air problems. We constructed three composite first-person narratives that reflected different experiential frames, with corresponding forms and changes of agency. We found that our adolescents made sense of the same socio-material environment and its affordances in very different ways, and this process afforded them to develop many kinds of agency that changed over time.