House prices that went up by 532% in Australia, 602% in Canada since 1990 now face the prospect of decline by 20 or 30% after sharp increase in interest rates by central banks in the US and other countries. US prices were up 289% since 1990 by comparison. The Fed's moves could also lead to a decline in US home prices as mortgages become costlier. As many mortgages are not fixed in Australia and Canada the costs can increase sharply with rising rates.