Abstract: Methods, computer program products, and systems are presented. The method computer program products, and systems can include, for instance: obtaining first building event transaction data of a building using a first data source; recording a first blockchain block in a blockchain ledger, the first blockchain block having a timestamp and the first building event transaction data; obtaining second building event transaction data of the building using a second data source; recording a second blockchain block in the blockchain ledger, the second blockchain block having a timestamp, and the second building event transaction data; examining data of the first blockchain block and the second blockchain block; and providing one or more output in dependence on the examining.

Abstract: Collaborative scene sharing for overcoming visual obstructions is provided. Video feeds of a scene are obtained from multiple devices viewing the scene from different angle. An obstruction obstructs portion(s) of the scene from view by a device. An aggregation grid that partitions views of the scene into cells is established and used in providing an aggregated view of the scene to the device. This includes identifying cell(s) of the aggregation grid for which the view by the device is obstructed by the obstruction, and providing to the device video portion(s) obtained from video feed(s) from the multiple devices. The video portion(s) correspond to the cell(s) for which the view by the device is obstructed, and the video feeds from which the video portions are obtained are from other device(s), of the multiple devices, for which the view for the cell(s) is unobstructed.