Childless couples are making up an increasingly large proportion of families - a trend that has been on the rise for more than 20 years, Statistics New Zealand says.
There were now 1.1 million families in New Zealand, according to 2013 Census data.
"Couples without children make up just over 40 per cent of all family types, up from 35 per cent in 1991," Census customer focus manager Gareth Meech said.
"Couples with children are still the most common family type, but the proportion of these families continues to fall."
Since 2006, the rise in the number of couples without children was almost double that of couples with children.
Marlborough was the only region where over half (53.2 per cent) of the families were couples without children, which reflected the older age structure of people in these families in this region, Mr Meech said.
One-parent families made up about 18 per cent of families, similar to figures in 2006.
Of the 1.5 million households in New Zealand, two-thirds contained one family, and just over 3 per cent had two or more families, the data said.
Other key points
• in one-third of one-parent families with dependent children, the parent was employed full-time;
• 9500 grandparents were in a parental role to their grandchildren;
• the number of extended families had increased by just over half since 2001;
• about one in four households were one-person households, with the West Coast region having the highest proportion, at 30.7 per cent; and
• the average New Zealand household size remained at 2.7 people.