The widespread availability of GPS-equipped mobile devices and the development of VGI communities such as Wikimapia or OpenStreetMap (OSM) enables the general public to collaboratively collect, share and distribute geographic information. In recent years, the quantity and quality of VGI has grown significantly to the extent that VGI represents a serious
alternative to geographic information collected by professionals. Th ese communities are also collecting increasing amounts of information about buildings: recently, the building footprints in OSM surpassed the amount of data on streets.
With the integration of additional sensors such as acceleration sensors, barometers, Near Field
Communication (NFC) and images, future mobile phones will enable the collection of indoor information. Th is indoor information can then – if an appropriate methodology for
modelling is available – be provided as VGI. However, the existing (outdoor) VGI methodologies need to be extended with methodologies for collecting and sharing indoor information. Th e authors designed an indoor mapping schema for OSM since, with more than 500,000 members, it is currently one of the largest VGI communities.