Patterson are you really suggesting it's "different this time"?
We've all seen the chart and I'd hardly consider the price action over the last few years to be sustainable or indeed representative of long-term returns from property. A substantial proportion of the driving force behind this boom comes from greedy baby boomers who believe that buying up properties is the solution to not having saved enough for retirement. Pretty much every house in my area at the low end of the market is being sold as "suitable for first-time buyer or investor".
A lot of people no longer trust the stock market or pension funds and are buying up these types of properties. I reckon these "investors" could be quite easily spooked by the prospect of a capital loss. It probably only takes the recent reduction in HPI and a few bearish articles in the media to put the wind up BTL and trigger a rash of low-end properties back on the market.