The head of building at Auckland City Council has some simple advice for anyone hiring someone to do work on their property.
"Ask them for examples of work they've done in the past and those good designers and builders - and there are plenty of them out there - they will be more than happy to put you in contact with people they have worked with before," said Ian McCormick.
Building is booming in Auckland, especially because of the housing shortage - but the council believes there are dodgy operators cashing in on the chaos by falsifying qualifications and paperwork.
Mr McCormick, Manager of Building Control, has described what he's seen as "extremely concerning".
Three fraud prosecutions involving those in the building industry are under way.
"Someone was purporting to be a structural engineer when they weren't. It's got significant implications for the building industry when people do that," Mr McCormick says.
Another case before the courts involves faked building consents.
"People will submit, to us or their client, a letter which appears to be from us saying that building consents have been received - that might be to trigger a payment from a client," Mr McCormick says.
Auckland Council Inspections Manager, Jeff Fahrensohn, says his team are doing 900 inspections a day and has "no time for people who cut corners - they're basically trying to cut costs."
The Inspector's top priority is sniffing out the dodgy operators.
"We need to deliver quality houses for the families - it is one thing providing the volume, but it's another keeping a cap on the shoddy builders out there, the people who are trying to make a quick buck," Mr Fahrensohn says.
Right now, Auckland Council is failing around 30 per cent of building inspections.