%0 Journal Article %T Estimating Accessibility Problems in the Swedish Housing Stock Using Citizen Science: The Housing Experiment 2021. %A Slaug B %A Granbom M %A Iwarsson S %J J Appl Gerontol %V 0 %N 0 %D 2024 Jul 18 %M 39023853 %F 2.645 %R 10.1177/07334648241262646 %X Accessible housing for the aging population is important, but large-scale reliable information on accessibility problems in ordinary housing is lacking. This study aimed to describe the prevalence of environmental barriers and analyze potential accessibility problems in the Swedish housing stock and to evaluate the validity and representativeness of housing data collected in a citizen science project. Data on environmental barriers in 1181 dwellings were collected by members of the public. Prevalence of barriers and potential accessibility problems were analyzed using descriptive statistics and ranking methodology. Validity and representativeness were addressed by comparisons with public statistics and research, and analysis of data properties. It was found there are substantial numbers of environmental barriers in dwellings across Sweden that generate accessibility problems for people with functional limitations. The results suggest that with user-friendly data collection tools and instructions, data validity and representativeness can be achieved in citizen science projects involving older adults.