'The decrease in the average size of new homes consented in recent years is partly due to the increasing proportion of multi-unit homes, which tend to be smaller than most stand-alone houses,” Mr Heslop said.

Floor area for new homes includes any attached garage, which is around 36 square metres for a typical double garage. Stand-alone houses are more likely than other home types to include a garage.

Homes consented in the 1970s remain the smallest in the series. The average floor area of new homes was 107 square metres at its lowest point in 1975.

Average consent value per square metre for new homes rises

The average value per square metre of all new homes consented in 2021 was $2,497, up 5.8 percent from $2,360 in 2020. For multi-unit homes, the average was $2,623 per square metre, and for stand-alone houses was $2,432 per square metre. Consent values exclude the cost of land, which varies by region.

The actual cost of building tends to be higher than the original consent value in many cases.

Prices for construction of new dwellings increased 16 percent in the December 2021 quarter compared with the December 2020 quarter as measured by the consumers price index. Annual inflation hits a three decade high at 5.9 per cent has more information.

Seasonally adjusted rise in number of new homes

The seasonally adjusted number of new homes consented in December 2021 rose 0.6 per cent, following a 0.6 per cent rise in November 2021.

On a quarterly basis, the seasonally adjusted number of new homes consented fell 1.2 per cent in the December 2021 quarter, the first quarterly fall since the March 2020 quarter.

Some periods of the year typically experience higher or lower numbers of new homes consented, so accounting for seasonality allows us to better compare numbers between periods.

For example, in December months, fewer consents are issued, partly as there are more public holidays and fewer working days (Monday to Friday) than in other months.