13% increase in a year is not sustainable but what usually happens is we get spurts like this then periods of flat or small increases so the long term average is around 8%.
The question comes up it that can continue and for how long, IMO the long term average may come down to say 5% so property values double every 15 years rather than 8-10 years.
Yes we will probably get a correction eventually but with strong demand due to population growth a 10% correction will bring buyers back in to the market as usual.
From long ago the idea that property doubles in value every 8-10 years seem to good to be true and each time it happened I had doubted it would happen again. But time and time again it has happened