The latest monthly figures, which were released by the Central Statistics Office yesterday, show that the rate of decline thus far in 2011 has been more rapid than in 2010.
Residential property prices nationally are now more than 43 per cent lower than their peak in September 2007.
The figures give no reason to believe to believe that the market has reached a bottom.
The comprehensive index, which was first published by the CSO earlier this year, gives detailed data by type of property (house/apartment) and by geography (Dublin/non-Dublin).
Two of the most marked trends in evidence since the property bubble burst in 2007 continued in August.
The first is that residential property prices in the capital have suffered more than those outside Dublin and the second is that apartment prices have fallen by more than those of houses. Both trends continued last month.
A precipitous monthly decline of 3.8 per cent in residential property prices was registered in Dublin in August. This was the second largest monthly decline on record and just below the 3.9 per cent falls registered in March and April 2009 when the market was in free-fall.
When broken down by property type, house prices in Dublin were down 3.4 per cent on July, while the price of apartments in the capital fell by 6 per cent. The latter figure is by far the biggest monthly rate of contraction on record.
House prices in Dublin are now 48 per cent lower than their peak in 2007, while those of apartments are 57 per cent lower. By contrast, residential property prices outside the capital fell by 0.3 per cent in August.
Non-Dublin residential property prices were just shy of 40 per cent off their 2007 peak last month. Non-Dublin house prices fell by 0.3 per cent in August.
The CSO does not provide figures on prices of apartments outside Dublin, but it can be inferred from the data that apartment prices declines in 2011 have been only slightly larger from those of houses outside the capital.