Some of the more interesting bit around what will be exempt. This rules could still change as this is the draft of what is open for submission currently. Full details on the IRD website are available.
New builds homes loans will have interest deductibility for 20 years only, however this will be transferrable. So I expect this will be a marketing tool in the coming years.
Interestingly it looks like adding a second dwelling will mean better tax rules. This could include relocatables as well.