"We have spent a lot of time improving those figures. The difference between whether they were overnight or living there may have decreased the count," said a Statistics NZ manager Gareth Meech.
The new figures also point to rising costs of housing pushing more people into motor camps, almost doubling from 2220 people in 2006 to 4059 seven years later, and boarding houses, up from 1602 to 2718.
The report said "the key reasons people lived in boarding houses included a lack of affordable housing (especially for unpartnered people), debt and housing discrimination".
Half of all those in boarding houses (1362) were in Auckland. Nationally, almost a quarter (22 per cent) of boarding house residents were of Asian ethnicity, 20 per cent were Maori, 19 per cent Pacific and 46 per cent European (people could nominate more than one ethnicity).
There was continued growth in aged residential care, up from 27,966 to 31,899, reflecting the ageing population. There were also big increases, reflecting better counts, in numbers in educational institutions (16,698) and other residential care, mainly for the disabled (6018).
Mr Meech said the numbers in hotels and other guest accommodation were a mix of students, seasonal workers and workers on short-term business, professional and labouring contracts. More than a third of them (4290) were in Auckland, and half of those were in the central business district and surrounding Waitemata Local Board area.
"It probably reflects the housing shortages in Auckland. People may not be able to find more permanent accommodation so they are forced to look for more temporary accommodation."
Just over half of those in Auckland guest accommodation were working (2121), of whom a third were managers and professionals who may be on short-term contracts and another quarter were technicians, trades workers and labourers.
In Christchurch a third of those who were working were also managers and professionals, but technicians, trades workers and labourers made up a bigger share than in Auckland (31 per cent), reflecting an influx of workers to rebuild the city.
Nationally, half of those whose usual residence was a hotel or guest accommodation were born overseas, and about a quarter were Asian. They were younger than average, with 28.5 per cent in their 20s.