My personal, completely uneducated, thoughts are that the housing market will drop over the next year, I'd be surprised by even 10% in non-inflation-adjusted terms though, let alone 30%...
But as has been said if you're buying a house to live in then the main thing to consider is whether you can afford now (guessing so seeing as you're considering it) and that you are sure that you can afford the mortgage if/when rates rise, essentially this means being very careful over long term trackers (imo)
If I was looking to buy right now I'd be looking at fixed rates for 3-5 years, preferably in the 4-5% region, as I think that interest rates will rise to at least 1% before the end of the year, if not closer to 2% (note that the historical 'normal' interest rates are 4-5%, so trackers could get painful over the next 2 years or more)
Of course I could well be completely wrong and house prices will rise, rates will stay at 0.5% forever more and we all live happily ever after ¬_¬