Unsold property inventories held by Auckland's largest agency doubled in the last year.

Last August, Barfoot & Thompson had 2601 Auckland and Northland residential properties for sale, but last month that hit 4637 unsold properties and in every month this year except January, the agency held more than 4000 unsold properties on its books.

Last June, it had 2864 and by July 2629 unsold properties.

Residential sales volumes were much higher last year, usually over more than 1000/month but last month, the agency only sold 578 properties, in July just 611 and in June just 684.

August's average residential price stood at $1.15m, up on July's $1.1m and but the median hardly moved from July's $1,110,000 to August's $1,111,000.

Peter Thompson, managing director, said Auckland house prices had plateaued in August while sales numbers remained low.

That meant the monthly downward slide in prices came to a halt in August, with the median sales price for the month remaining constant with that for July while the average price increased, he said.

"Previously, the average sales price had fallen four months in a row, but in August that trend was reversed with the average price over the previous month increasing by 3.1 per cent to $1,157,899."

Rather than signalling that prices are on the increase, this reversal is likely to be an indication that prices are plateauing.

"The prices being paid in August are still below those being paid in August last year, but the average price was down only 2 per cent and the median price down 1.7 per cent," Thompson said today.

"Where the market is really seeing change is in the number of properties being sold, with sales numbers in August of 578 our lowest in a month since the Covid affected sales months in mid-2020.

"Given that there are buyers in the market, the combination of low sales numbers and stable prices indicates that vendors believe prices are bottoming out."

New vendors continue to arrive and in August the agency listed 1394 new properties, "our highest number of new listings in the month of August for six years".

"At month end we had 4637 properties on our books, our highest number of listings at the end of August for 11 years. With high new listings, including new builds entering the market for the first time and a solid base of existing properties we enter the normally buoyant spring buying season with an excellent range of properties and choice for buyers."

Around 18 per cent of sales were for properties which sold for $750,000. Only 8 per cent of sales were for properties above $2m.

Last week, the Herald reported the Financial Times asking if the New Zealand housing market is the canary in the coal mine - or in our case, the kiwi down the pit.

Economists globally are watching what happens to our residential values because we could be leading the way in terms of a massive adjustment in valuations. The video was headlined "NZ house market: warning to the world?"

New research from Goldman Sachs's Australian-based Bill Zu also reported last week forecast a 25 per cent drop in NZ house prices.

"We now expect a peak-to-trough price decline of around 20-25 per cent before stabilising around late 2023 or early 2024," Zu said.

"More pain ahead" was his headline in the report which noted how rapidly our housing market is cooling, alongside what Zu called the aggressive tightening cycle by the Reserve Bank's monetary policy moves.

Jarden's equity research analyst Grant Swanepoel forecast prices to fall by 18 per cent by the end of next year from a national average of $905,000 to $740,000. Auckland prices are now down 16 per cent from the peak, he noted.