Owning your own home

Anyone looking at the Royal mail share offering for example? I see it giving a much greater return than the average for UK property currently over the long term.
How can you be sure that you're going to be investing in the next British Gas, and not the next Railtrack? Or that this has not been priced in already, normalising expected returns.

House prices have consistently outpaced the stock market in the mid- to long-term, particularly in the South East, for decades.