Homes in shadowy or damper areas, as well as homes built before 1962, are more at risk to pest infestations such as borer, a Wellington inquiry has found.
The investigation into Wellington's housing stock has also found 60 per cent of inspected Wellington homes have earthquake or weather resilience issues.
Borer infestations, poor weather proofing and insecure foundations were the main issues, initial investigations have found.
"It's issues that might be small can grow, and might not be an issue for a long time but in an event like an earthquake is when we need our homes the most," Wellington City Council chief resilience officer Mike Mendonca says.
Half of the inspected homes had some kind of borer infestation, while many had major ones.
"If you have that in your framing, obviously your house won't be as strong," Mr Mendonca said.
The inquiry was sparked after the results from inspections from 100 city homes over two years were concerning.
The council then lined up another 500 homes for inspection before the end of the year.
It is working on putting together a programme to upgrade homes, but says it's still in the early stages.
The council is hoping it will gather support, not only financial, from the government and building partners, but isn't sure what that will comprise at this stage.
People who buy homes aren't looking past the aesthetics enough, Mr Mendonca says.