The relationship between dwelling approvals, commencements and completions

Earlier this week the Australian Bureau of Statistics (ABS) released building activity data for the December 2014 quarter.

The data includes quarterly figures for dwelling commencements and dwelling completions. With a record number of dwelling approvals coming through the system, it is important to track this data as it provides insight into how many of these approvals are ultimately being constructed.

Over the past 30 years, approvals and commencements have been highly correlated with the vast majority being approved and commenced in the same quarter. If we look at the relationship between approvals and completions, most houses are completed two quarters after approval while most units are constructed three quarters after being approved.

Based on this data over the past 30 years, 96.5% of house approvals have moved to the commencement phase and 96.2% of unit approvals have been commenced.

Looking at the completion rate for houses based on a two quarter lag, 95.1% of houses which have been approved are ultimately completed. For units the completion rate has been somewhat lower. Using a three quarter lag between approval and completion, 86.9% of units approved for construction have been completed.

On this logic, detached housing approvals are much more likely to result in a completed product, with a fallout rate of just 5%, while apartment approvals are less likely to ultimately be constructed, with a dropout rate close to 15%.