The proportion of one-bedroom property tenancies has increased by 85 per cent and now represents almost a quarter of all properties let within the Auckland region.
The North Shore has the biggest places while the CBD has the smallest.
The Shore had the largest share of rental agreements for four or more bedroom homes, making up 23 per cent of its rentals, Barfoots found.
Auckland city had the largest share of one-bedrooms at 36 per cent. Waitakere had the least one-bedroom rentals, at just 4 per cent.
"Auckland's housing needs have changed. The drivers of this have been changing family structures, increasing international immigration and multiculturalism, and evolving attitudes to lifestyles and expectations among Auckland's population.
"Combined with this shift in what renters need and want, the housing stock itself has been evolving. This is evident in new developments, such as the Antipodean in the CBD, with a range of different sized homes being integrated into the plans.
"Another interesting trend we noticed in the data is that it's only recently that the proportion of one-bedroom and four or five-plus bedroom properties being rented increased. The number of bedrooms had been fairly stable before that. Our data also shows a large increase in properties with more than four bedrooms compared with five years ago," Barfoot said.
Residential property manager Crockers also released research findings this month and weekly rental price data.
"Over the past month, average Auckland rents for a two-bedroom residential property decreased slightly from $481 to $477," Crockers said of weekly payments.
"New Zealand two-bedroom rents also decreased slightly over the same period from $395 to $390. The Auckland two-bedroom premium has held steady at 22 per cent in April.
Rents for three-bedroom properties in Auckland increased from $606 to $614 in April, while three-bedroom rents across New Zealand remained steady at $460. This has resulted in the Auckland three-bedroom premium increasing slightly to 34 per cent in April."