Census - Total (occupied and unoccupied) private dwelling count and change by region 2006, 2013, and 2018

Census usually resident population count of New Zealand: a count of all people who usually live in and were present in New Zealand on census night. It excludes overseas visitors and New Zealand residents who are temporarily overseas.
Census night population count of New Zealand: a count of all people present in New Zealand on census night. This includes visitors from overseas who are counted on census night but excludes residents who are temporarily overseas on census night.
Private dwelling (home): A private dwelling accommodates a person or a group of people. It is not generally available for public use. The main purpose of a private dwelling is as a place of habitation, and it is usually built (or converted) to function as a self-contained housing unit. A home may be occupied or unoccupied (empty or residents away) on census night.

http://datainfoplus.stats.govt.nz/Item/nz.govt.stats/ca28210f-3fd6-415c-a162-ecc07b4a28b0

Geographically the census includes the North Island, South Island, Stewart Island, and the Chatham Islands, plus largely uninhabited islands including the Kermadec Islands, Three Kings Islands, Mayor Island, Motiti Island, White Island, Moutohora Island, Bounty Islands, Snares Islands, Antipodes Islands, Auckland Islands, and Campbell Island.

The 2018 Census was a modernised census based on models used in 2016 by the Canadian and Australian statistical agencies and then applied in the New Zealand context. Stats NZ collaborated with census experts from both countries when designing the model.

Under the new model, how Stats NZ enabled/collected from the respondents changed from predominately field-based activities to 80 percent mail-out with a reduced field presence and increased communications, marketing and engagement. The way respondents completed their forms also changed, with a greater focus on online completion over paper. The majority of the population was encouraged to complete the census online using an internet access code mailed to their households before census night. The new collection model therefore relied on the public to self-respond, rather than wait for a visit from field staff. Field follow-up activities were also planned.

The main areas of change were:
- phasing the model (prepare, enable, remind and visit)
- strategies used across the different phases
- mailing out “call to action” letters with an internet access code and instructions on how to order paper forms, if required, as the first interaction with census
- reducing the number of field staff, with a new structure and roles
- outsourcing the recruitment functions for field staff
- introducing new field technology
- creating a new address frame (a list of all dwellings in New Zealand)
- an integrated communications campaign including community engagement
- a new approach to processing the census data.

At URL provided, select "2018 Census population and dwelling counts – amended" to download the file.

The New Zealand Census of Population and Dwellings is the official count of how many people and dwellings there are in New Zealand. It provides a snapshot of our society at a point in time and helps to tell the story of its social and economic change. The 2018 Census, held on Tuesday 6 March, was the 34th New Zealand Census of Population and Dwellings. The first official census was run in 1851, and since 1877 there has been a census every five years, with only four exceptions.

Census information is used by government agencies, local authorities, businesses, community organisations, and the public for developing and implementing new policies, research, planning, and decision-making. It helps us make decisions about how to best use public funding, especially in areas of health, education, housing, and transport.
The census is also the primary source of information used for deciding the number of general and Māori electorates, along with data from the corresponding Māori Electoral Option.