• Documentation describes room event data returned by room.getEventLog() for event type EVENT_BUILD as follows

    https://docs.screeps.com/api/#Room.getEventLog

    EVENT_BUILD	A creep performed build in the room.
    targetId - the target object ID
    amount - the amount of build progress gained
    energySpent - the energy amount spent on the operation
    
    the actual event data in game contains the following:
    
    targetId,
    amount,
    structureType
    x,
    y,
    incomplete: boolean // gets set to true, if this action completed the site build