When a politician, any politician, tells you they have a comprehensive plan for housing and housing affordability, my advice would be to take any claims they make with a large grain of salt.

I'd suggest it be applied to the latest offering from the Labour Party.

While the party of late has come around to the fact that addressing land supply is just as important as state sponsored building programmes, and National has begrudgingly realised the state also can play a part in encouraging housing developments beyond merely changing regulations to make land available for development - both parties have ignored, or are blissfully unaware of, multiple other factors that stand in the way of cheaper housing. They certainly don't seem to have been addressed in any policy announcements either side have been making.

Firstly, there are some cultural issues to overcome. New Zealand has never really been a country that's gone in for terraced housing; rather we're a country where people aim to buy a stand-alone house on an individual section. Nor are we a country where there's been a strong tradition of bulk building, our houses tend to be more individual in their design. To build cheaply you have to build in bulk, and intensively.

Secondly, our building industry isn’t set up for affordable housing. It's not an industry dominated by large companies, instead smaller outfits are the norm - owner builders and the like. These are outfits that need margins to make a profit. Margins on affordable houses are limited so the economic incentive to pursue them is limited.

It's worth noting the first time Labour came up with its KiwiBuild policy, the party's then Leader David Shearer, was unable to name the private companies that could take the work on. That question from 2013 is just as valid now in light of Labour's latest tweak of the policy - to build 100,000 affordable homes over 10 years, who is going to build these houses? Particularly given the pressures and demands the sector is currently facing.

An answer to this question does need to be provided.

But what really jars about Labour's 2016 incarnation of its KiwiBuild policy is its estimate of the cost of the affordable homes it would create in Auckland. In his speech announcing the policy Andrew Little put the figure at over half a million dollars for a house and up to half a million dollars for an apartment, and while that's significantly lower than the current average house price in Auckland, it might as well be a million dollars for a blue collar worker earning the average wage.

A workers' party really should aspire to do better.