When EQC inspected our house (which at the time was less than a year old), I questioned the lead inspector on how they determine damage that is caused by EQ and damage that has been caused intentionally by say the home owner, and damage that has been there prior to the quakes. He simply said, "Having 30 years in the building industry and with all the tricks he's recently seen from EQC inspections, his eyes can see the difference".
CCC: you need to determine if your claim is true and if EQC is denying your position. What they won't do is build you a brand new house if your existing house falls under the category of Leaky House Syndrome as these houses have the problem of rotting regardless if in 2 years or in 20 years time. They could argue that the rotting portions of your house may of contributed to the damage inside from the earthquake.
I'm sure you're aware Leaky Home claims have been apportioned to 1/3 cost to NZ gov't, 1/3 by local city council, & 1/3 cost to the home owner.