Sydney and Melbourne home prices could fall by 20 per cent as the Reserve Bank of Australia, which has lifted interest rates by 75 basis points in the past five weeks, moves aggressively to stifle demand and tame inflation.

Cameron Kusher, executive manager for economic research at REA Group, said the RBA is moving quicker than anticipated and predicted national dwelling prices will fall by 10 per cent to 15 per cent, and higher in Melbourne and Sydney.