Data for the year to September 30, based on number of first-home-buyer mortgages, showed housing affordability proved an ongoing issue in Auckland (down 5 per cent) as it was in the Bay of Plenty (down 11 per cent) and Taranaki (down 15 per cent).
Westpac said loan-to-value ratio restrictions continued to dampen demand in Auckland.
"In saying that, based on our data, we have seen first-home buyers roar back into the market in Wellington and in many of the other regions, and this has been helped by the new investor LVR rules. Flat prices will assist that further."
First-home buying shot up by 43 per cent in Wellington, 26 per cent in Manawatu-Wanganui, 74 per cent in Marlborough, 30 per cent in Nelson and 44 per cent in Northland.
Westpac's data showed one in five first-home buyers were using KiwiSaver for their deposit.
"Flat market will allow incomes to grow, improving affordability and we think interest rates are going to stay low through next year. So that's all good news for first-home buyers," the bank said.
"We also expect the Government's policies on both the supply and the demand side will have some effect at the margins."