Addressing the issues around housing in New Zealand, particularly in Auckland, is going to require a multi-pronged approach. It seems clear that we are facing a lack of a sufficient supply of suitable housing for our population, let alone for the further people that make up our projected growth over the next 30 years. There are several different trends that appear to be influencing supply, with none of them being the singular cause behind our problems.
I personally advocate for the government itself to properly get back into the business of building and repairing houses for social (welfare) housing, and for state housing (sold to or rented by regular citizens), thereby increasing supply and directing it to the people that need it the most. Such houses should be suitable for a range of lifestyle options, from low to high density. All should be of good quality and readily maintainable construction however. Intervention should be taken in the form of regulation that improves tenant protection, disincentivises speculative investment, and restores housing to a fundamental social resource rather than a speculative commodity.
Looking at the Auckland situation, rural urban boundaries should be maintained in order to prevent tragedies of the commons via piecemeal development. The council could instead look to model Auckland as one might hope for it to look in 50 years time, and then use that model to plan the development of new town centres, commercial zones, and housing developments. High-density living options should be promoted, but in a strategic manner that does not require the sacrifice of our leafy suburbs and the amenities to be had from present-day Auckland. If central government is not motivated to build houses, the TA might instead get into the business of building genuinely affordable homes for its citizens.