Homes in the superheated Auckland property market have been rising in price by nearly $500 a day.

Prices rose on average by $483 every day last month, according to monthly statistics from the city's largest real estate agency.

Barfoot & Thompson director Peter Thompson said the average Auckland house price shot from $325,831 in August to $340,329 in September, according to statistics gathered from deals his agents had done.

This means that houses in the country's hottest housing market rose $14,498 in the 30 days in September - one of the largest price jumps on record.

The price surge suggests a house selling for $300,000 at the start of September could be worth $358,926 by the end of the year.

Mr Thompson said: "The increase in the average price being paid in Auckland is even more significant when you consider that it's almost $50,000 more than it was a year ago."

The Real Estate Institute issued more conservative price rises for Auckland houses this month, pointing to a $5000 rise in the median for August. Barfoot & Thompson, with about 800 agents in 53 offices throughout the city, estimates it has 38 per cent of all house sales in Auckland, making it the largest agency.

Volumes of properties sold last month were also well up, rising by 72 per cent compared with September last year. This set a record, Mr Thompson said.

The agency sold 1228 residential properties in September, compared with 712 in September last year. More than 30 per cent of sales were made in the top end of the market, where properties sell for more than $500,000.

But the rising residential fortunes are creating a shortage of houses to list.

"Our biggest problem is lack of good-quality listings," Mr Thompson said. "We only had 4817 properties on our books at the end of last month, which is a five-year low."

ASB Bank chief economist Anthony Byett released data yesterday to show the national housing market would get even hotter.

House prices are expected to rise in the next 12 months, he found.

Net inward migration, a tight supply of houses and stable-to-lower interest rates were all combining to put further force behind the market, Mr Byett said.

Houses were selling fast and the relatively small numbers being listed for sale were fuelling demand.