Houses in 465 suburbs, or 5 per cent of all housing markets around the country, now fetch a $4 million median price, nearly double that of a year ago, as the potent combination of low interest rates, high savings and strong performance in some parts of the economy fuels rapid growth in the upper end, research from Ray White shows.

Analysis of 9315 suburbs by Ray White chief economist Nerida Conisbee also found that one in 10 housing markets had a median price of more than $3 million, more than triple from a decade ago.