The average annual household income has risen 41 percent since 2008, up more than twice the rate of inflation, says Stats NZ.

Over the same period, average annual housing costs increased 43 percent.

'Although average household income grew 41 percent over the last decade, individual households experienced this growth differently,” labour market and household statistics senior manager Jason Attewell says.

'While income for the poorest tenth of household grew 29 percent, for the richest tenth, income grew 47 percent.”

From 2008, the average annual household income rose just over $30,000, to reach $105,719 before tax, in 2018. Over the same period, average annual housing costs increased 43 percent, from $11,967 to $17,122, according to the latest household income and housing-cost statistics. Inflation as measured by the consumers price index increased 17 percent over the same period.

Household income includes any income from wages and salaries, self-employment, investments, government benefits, and superannuation. Housing costs include rent and mortgages, property rates, and building-related insurance.

Housing costs to income ratio remains unchanged from 2008.

For the year ended June 2018, household spent an average of $16.30 of every $100 of their household income on housing costs. This is relatively unchanged from the $16 they spent a decade ago.

'Although the ratio of housing costs to household income hasn't changed significantly over the last decade, certain types of household, such as renters and poorer households, pay a higher proportion of housing costs,” Jason says.

For the year ended June 2018, one in five of renting households spent 40 percent or more of their household income on housing costs, including rent. This compared with 7.5 percent of homeowners who spent that much of their household income on housing costs, including mortgages.

'The ratio of housing costs to household income is an important measure, because of a high proportion of housing costs is often associated with financial strain, particularly for lower-income households,” says Jason.

For the year ended June 2018, the average weekly housing cost was $338.60, almost unchanged from 2017. This included building insurance, which increased significantly from $30.60 per week to $34.10 – an 11 percent increase.

Since the February 2011 Christchurch earthquake, spending on building insurance has more than doubled from $16.60 per week in 2011 to $34.10 in 2018.