The average household income rose 2.3 per cent over the past year, while average housing costs were flat.
Statistics New Zealand's household economic survey found that in the year to June the average household income from all sources before tax was $81,067, up 2.3 per cent on the year before or 1.3 per cent after inflation.
That represents nearly half the rise in the average household income over the past five years, which was a cumulative 2.8 per cent in real terms.
In the latest year wages and salaries drove income growth.
For the 74 per cent of households with at least one wage or salary earner, gross income rose 5.4 per cent on average.
Income growth was most marked at the top and the bottom of the income scale.
The number of households with an income of more than $104,000, the cut-off level for the highest quartile in 2010/11, rose 7.2 per cent. The number with an income below $33,000, the boundary of the lowest quartile in 2010/11, fell by 7.7 per cent.
Households' average housing costs - mortgage payments, rent, rates and insurance - showed no change overall at $249 a week.
That masked differing fortunes between households with mortgages and those paying rent.
Mortgage interest costs fell 7.8 per cent to $234 a week on average, while the average rent rose 4.6 per cent to $273 a week.
Among households paying rent, 23 per cent face housing costs of more than 40 per cent of their gross income.
Among owner-occupiers, which includes those who have paid off their mortgage, 7 per cent have housing costs over 40 per cent of income.
Overall, housing costs took a slightly smaller share of household income in the past year - 16 per cent compared with 16.4 per cent in 2010/11.
In Auckland the decline was more marked, from 19.4 to 17.8 per cent.
But at an average $16,600 a year, housing costs in Auckland were still $3600 or 28 per cent higher than the national average, while the average household income is 15 per cent higher.