These figures came from Homes.co.nz's analysis of council decade sets on new builds.
CoreLogic Head of research Nick Goodall said houses alone were not as common as they previously were.
"Five years ago 80 per cent of new consents were houses, now it's under 50 per cent.
"No doubt this is an accepted consequence of the Auckland Unitary Plan ... and the nature of urban renewal required in a city with very limited land and large population growth.
Homes.co.nz chief marketing officer Jeremy O'Hanlon expected the downward trend would continue.
"If we extend this trend out another 20 years you'd expect the average section-size for a new home to come in at around 260sq m."
Head of Trade Me Property Nigel Jeffries said the changes could be put down to Kiwis' changing expectations when it comes to both the size of the house and the section.
"The quarter-acre dream has slowly become a thing of the past and buyers are having to downsize in order to secure the property they want.
"As property prices have soared in recent years, it's not surprising that many Aucklanders have had to downsize in order to get a foot on the property ladder."
Across Trade Me's for-sale listings the median size of an Auckland City section with existing property was slightly larger than the 499sq m of a new-build section - 508sq m in 2017.
Jeffries said the smaller sections and the apartment lifestyle came with some benefits.
"The maintenance on these properties is far lower, they're cheaper than a traditional house and they're typically located right in the centre of town."
Kimberley Ubels' first step onto the property ladder came in the form of a smaller section and house in the west Auckland suburb of Avondale.
She bought the 54sq m cottage, on approximately 230sq m of land on Kelvinside Terrace in 2013.
The then-single working professional had been scouring the city's housing market for some time.
"I wanted to buy, I had some savings ... I could see things were elevating [beyond] what I could afford."
She stumbled across the petite cottage which was on sale for a good price and decided to buy.
"It appealed because it was the same size, if not bigger than an apartment or unit. I had all my own space with some land and I could do whatever I wanted in essence to it."
Public records showed it was bought in 2013 for $383,000 and today has a rating valuation of $560,000.
Ubels, who is now married and has a six-month-old boy, no longer lives in the property.
"I ended up moving out and renting the house and went flatting, so I could save money to pay it off faster."
She's now living with her husband in their three-bedroom property on Herald Island and said it no longer made sense to keep the other one, so she was selling the cottage which will be up for auction next month.
She said it would be a great first house for anyone looking to get their foot on the property ladder.
"It didn't feel that small to me, it was definitely big enough for one person ... it was nice to have your own backyard and your own house that you can make changes to."
Auckland new-build section sizes
Pre-1990s: 731sq m
1990s: 634sq m
2000s: 530sq m
2010s: 513sq m
2017: 499sq m
Nationwide sizes
Pre-1990s: 762sq m
1990s: 680sq m
2000s: 642sq m
2010s: 631sq m
2017: 617sq m
