In Otago, the figures are similar to those for the rest of New Zealand, which showed an unexpected recovery in July was what the institute called "well and truly reversed" last month.
But figures for Dunedin were not all bad, institute Otago branch president Stephen Johnston said on Thursday.
Otago's real estate agents sold 188 houses in August, which was down from 217 in July, and 245 in August last year.
The median price dropped from $240,000 in July to $230,000 in August, compared to $238,000 in August last year.
Dunedin, at least, made a comeback from the a low of 131 houses sold in June, with 180 sold in July and 152 in August.
REINZ national president Murray Cleland said he believed economists were correct with predictions of a 5% to 10% decrease in the market, followed by a period of stability late this year or early next year.
History showed the market normally recovered from low winter sales from September 1, "so all I can say is there is a lot riding on spring".
Mr Johnston said agents had reported good activity in August, the results of which would come through this month when sales were finalised, though it was too early to say if that was evidence of a spring recovery.
Figures for the city showed the "hype" of recent times had left the market, which was returning to normal, and the figures were not terrible news.
Graphs he provided for the last year showed a median price that had hovered around the $250,000 level with little significant change.
The vast majority of sales in Dunedin were of homes between $200,000 and $300,000, he said.
Sales numbers had fallen since the start of the year, but were also reasonably consistent around the 150 mark.
People really wanting to sell were able to, and there were "some good buys out there".
