Eric Crampton makes many good points, here is one of them:
But that gets us to one of the risks: the intersection of Labour, Green and New Zealand First’s core beliefs is distrustful of markets and of foreigners. I can’t see how we get anywhere close to the proposed 100,000 houses built in any reasonable time without allowing foreign workers, materials, capital and expertise to help.
New Zealand’s Overseas Investment Regime already makes us the most restrictive in the OECD. Any land adjacent to a reserve must go through the screening regime, and it will be tough to ease that back under the current coalition. Heck, even New Zealand’s Fletcher Construction has to jump through Overseas Investment Act hurdles because it has foreign shareholders. New Zealand First has proposed cutting immigration numbers substantially, and Labour and the Greens have been very sympathetic to that view. The incoming government has also signaled an intention to re-negotiate trade agreements to allow banning non-residents from buying houses. If supply issues are appropriately addressed, the ban does no good and could backfire if it prevents foreign investors from building houses here to rent out.
Vernon Small offers a more pessimistic take.