New Zealand Prime Minister Jacinda Ardern says a ban on foreigners buying existing homes will begin in early 2018, but won't apply to Australians seeking to buy homes across the ditch.

The mythical unicorn is a creature of elf-enchanted forests. It's also the term used in the credit scoring industry for a person with an unfeasibly high credit score. This week saw the launch of Creditsimple.co.nz which provides free instant access to your credit score, which places you on a scale of 0-1000.

"Mission Bay's ideal location and mix of city and coastal lifestyles make it a very desirable and high-end suburb. We've seen this demand push prices up across the board, and have also been involved in a greater number of high-value, multi-million dollar property sales," said Andy MacDonald, Barfoot & Thompson Mission Bay branch manager.

The New Zealand Reserve Bank's new restrictions on highly-leveraged home loans are likely to be a boon to non-bank lenders, which make up a fraction of all mortgages. The central bank expects a drop of up to 15 per cent in the volume of home sales and reduce house price inflation by up to 5 per cent when it introduces restrictions on banks' high loan-to-value ratio mortgages from September.