Good shout. Saying that, my in-laws neighbour had a chicken shed done in that fashion, had been there for a decade or more, but about ten years ago there was a really strong storm and thing was blown half way across their driveway (about 20m). Took four of us to put it back, we couldn't believe something that size and weight could be moved by the wind in this country. If yer in a built up area, you'd likely be fine though.