Twobobs,
Intuitively I'd call it above average capital price growth and you can measure this as a fixed percent if you like, but 10-15%pa would fit the bill.
For me though, its a stage in the property cycle so I look for lead indicators of this stage not the lag indicators of actual price performance. The sort of lead indicators can be gleaned from any good property clock. Some things to watch for are the demand/supply situation, interest rates and market participants. Typically FHBs lead the recovery when rates fall to stimulate the market. Investors move in second, and once the boom is well under way, upgraders return and compete with investors to top out the boom. Market participation is a good lead indicator.
FWIW, we're in early boom stages in Sydney now with FHBers leading and now being replaced by investors. As soon as upgraders feel secure in re-entering the market it will take off and become self-fulfilling for a while. 2011/2012 looks like the next peak sort of timeframe at this stage.
Cheers,
Michael