It will depend on your flying mode. In tripod mode it will come to a stop in front of the obstacle, until you guide it clear of the obstacle. In normal mode it will either go around or over the obstacle. In sport mode all obstacle avoidance is turned off. Because your RTH is set at 60m, your aircraft would fly into the building at 60m high. Always set your RTH higher than the tallest tree, building, or power line wherever you are flying.