There are plenty of reasons, but as the Reserve Bank of Australia said last week with regard to the record 6.8% rise in Australia house prices in the three months to June, the main cause is record low interest rates.
For us in New Zealand it wasn’t just the 0.75% cut in the official cash rate to 0.25% in March last year. There was already the acceleration in the pace of house price growth coming about because of the 0.75% cut in NZ interest rates in mid-2019.