Average annual housing costs in New Zealand

Housing costs include expenditure on rents and mortgages, property rates, and building-related insurance.
Income figures are collected for people aged 15 years and over.
Household income is from disposable (after tax) income.
Ratios are calculated using the aggregate housing-cost amount as a proportion of the aggregate disposable household-income amount and are rounded to nearest one decimal place.

Household: is either one person who usually resides alone, or two or more people who usually reside together and share facilities (such as for eating or cooking) in a private dwelling. A household may contain one or more families, other people in addition to a family, or no families at all, such as unrelated people living together.
Disposable income: total income plus tax credits, less ACC levy, less tax payable.
Total housing costs: consists of expenditure from mortgage principal repayments, mortgage interest payments, mortgage application fees, rent payments, other payments associated with renting (for example bonds paid in the last 12 months), property rates payments (both regional and local government), and payments associated with building-related insurance.

http://datainfoplus.stats.govt.nz/Item/nz.govt.stats/27d850c1-939c-4e93-b61c-a1b5196b7f27

As with the Household Economic Survey for the year ended June 2020, 2021, and 2022, the pandemic has impacted Stats NZ’s ability to conduct face-to-face interviews in respondent’s homes and no other means of interviewing were available. Therefore, interviewing was not conducted evenly over the whole year. Consequently, the sample size was reduced to 8,900 households from the planned 20,000 households. The reduced sample size means margins of error on the statistics are higher than designed for.

The target population for HES (Income) is the usually resident population of New Zealand living in private dwellings, aged 15 years and over. This population does not include:
- overseas visitors who are in New Zealand for less than 12 months
- people living in non-private dwellings such as hotels, motels, boarding houses, hostels, and homes for the elderly
- patients in hospitals, or residents of psychiatric or penal institutions
- members of the permanent armed forces in group living facilities; for example, barracks
- people living on offshore islands (excluding Waiheke Island)
- members of the non-New Zealand armed forces
- non-New Zealand diplomats and their families.

At URL provided, select 'Household income and housing-cost statistics: Year ended June 2023' from under the 'Download Data' heading.

The household economic survey (HES) is an annual survey designed to measure the economic wellbeing of New Zealanders. HES has three components: HES income, HES expenditure, and HES net worth.
- HES income is the main vehicle, and it is run every year. It includes household income, housing costs, and material wellbeing – this is ‘core’ HES.
- HES expenditure includes additional components – an expenditure diary and an expanded household expenditure questionnaire. It runs every three years.
- HES net worth includes additional questions on household assets and liabilities. It also runs every three years.

The three main objectives of HES (Income) are to measure patterns of inequality in household income (used for policy-making decisions); measure people’s life satisfaction, housing conditions, and financial stress; provide an indication of the overall living standards of New Zealanders.