The number of building approvals unexpectedly rose 7.6 per cent in September in a pick-up that slowed the rate of annual decline but is expected to be short-lived.

Approvals for private sector houses rose 2.8 per cent on a seasonally adjusted basis, but the largest rise came with a 16 per cent monthly rise in the volatile “other dwellings” category that includes apartment blocks and townhouses.

But although Thursday’s data comfortably beat market consensus of a flat result, economist warned against reading too much into just a second positive reading in seven months.

“The latest increase doesn’t signal the end of the prevailing weakness in residential construction. We are not at a turning point,” St George economist Nelson Aston said.

“Approvals can be volatile on a month-to-month basis and have been trending lower since last 2017. Developers have been scaling back projects in response to the slowdown in demand from its peak and uncertainty amid building-quality issues.”

Over the 12 months to September, the fall in total building approvals moderated to 19.0 per cent from 21.5 per cent a month earlier, the Australian Bureau of Statistics said.

BIS Oxford Economics principal economist Tim Hibbert agreed that the rise would likely prove short-lived.

“Rate cuts combined with eased mortgage serviceability guidelines, have opened up access to credit, helping the established residential market regain it footing over recent months,” Mr Hibbert said.

“However, it is not until June quarter next year that these measures are expected to drive sustained growth in dwelling approvals.”

The estimated value of total approvals fell 16.6 per cent in September, driven by a 36.6 per cent fall in the value of non-residential approvals.

The Australian dollar, already rising against the US dollar, ticked higher after the data’s release, going from 69.03 at 1130 AEDT to as high as 69.30 US cents.