An academic says Mainzeal's nine years of trading while insolvent - needs to be seen in context of an industry that runs on fine margins.

The construction company collapsed in 2013, leaving creditors millions in debt.

The board of directors, including former PM Dame Jenny Shipley, have been ordered by the High Court to pay $36 million for letting it run so far.

Head of AUT's  Built Environment Department, John Tookey, told Kate Hawkesby many companies run a fine line between profit and bust.

"The building industry has very low margins and consequently there are a lot of companies that operate, not exactly in liquid, but very close to liquidity. It can become a cultural thing, you operate very close to the wire and you just let it run and run."