Auckland house sales didn't get the boost expected in spring, with price growth moderating, Barfoot & Thompson says.

Sales rose 4.8 per cent to 1,051 in September compared to August, but were down 23 per cent from the same month a year earlier, the city’s biggest realtor said.

The median sale price was unchanged at $850,000 from a month prior and was 7.6 per cent higher than a year earlier. The average price was $919,849, which is 1.5 per cent higher than a month earlier, and 10 per cent higher than September 2015.

“With the arrival of spring, housing activity normally lifts, but it has not been the case this year,” managing director Peter Thompson said.

“Rather, the market continued the trend which first showed in July of prices increasing at a much slower rate than in the past two to three years. Compared to what was happening to prices last September the Auckland housing market is subdued and we are now looking at a totally different market to 12 months ago.”

The Reserve Bank’s extended mortgage lending restrictions officially came into effect this month, though the major banks had already begun following them.

The changes cap property investor loans with less than 40 per cent as a deposit to just 5 per cent of lending and restrict owner-occupiers with less than a fifth down to 10 per cent.

The central bank is trying to curb demand for property where prices have soared at a faster rate than wages, leaving households with larger mortgages and making housing less affordable for people on modest incomes. A lack of housing in Auckland combined with record migration and low interest rates have stoked the rapid jump in prices over the past few years.

Mr Thompson said sales hadn’t been affected at the high end of the market, with 38 per cent of properties sold at $1 million or more, while just 7.7 per cent of properties sold for under $500,000.

The realtor’s number of new listings fell 10 per cent in September and are more than a fifth lower than the same month a year earlier.