Housing affordability is improving, a new Massey University report shows, but its authors do not expect that to last.

The latest Massey University Home Affordability Report shows some improvement in affordability figures over the past three months, due mainly to falling mortgage rates and static house prices.

"Even Auckland falls in line with this trend – affordability in our largest city has improved by 4.9 per cent since our last report in June," Massey University senior property lecturer Susan Flint-Hartle said.

"Having said that, affordability in Auckland has still decreased by 16.6 per cent over the past 12 months."

The report, which covers the period from June to August, shows home affordability across New Zealand improved by 2.3 per cent over the quarter, but the national index still shows a year-on-year decline of 6.7 per cent.

"While affordability trends show some improvement in this report, the relative levels of affordability across the country haven't really changed much. You must remember that these small improvements are coming off the back of historic levels of unaffordability," Flint-Hartle said.

She did not expect affordability to continue to improve.

"It's a bit of a lull caused mainly by lower interest rates. That makes people think their monthly payments are less and they can afford more. It initially has the effect of improving affordability but if it continues it is likely to draw more people into the market which stimulates demand. It's a bit of a double-edged sword."

Looming tax changes, which will mean any investor who buys and sells within two years will pay a capital gains tax, could delay further house price rises, she said.

Auckland remains 52 per cent "less affordable" than the national average – down slightly from 56 per cent last quarter, but still close to that historic high.

Regional movements in affordability have largely been driven by house prices. Central Otago Lakes, Southland, Manawatu/Wanganui, Northland and Taranaki, which experienced the largest improvements in affordability, also had the largest falls in house prices.

"The only region not to show some improvement over the past three months was Nelson/Marlborough, where house prices increased by the largest margin," Flint-Hartle said.

Flint-Hartle said young borrowers who had taken out large mortgages to get into the market would feel the squeeze once interest rates started to rise again.

But she said that was likely still some time off and many had fixed their loans over long terms to guard against it.