What does it really cost to get a certificate of compliance?

In my advice about what to do if your solar water system's installer did not obtain a Building Consent before proceeding, I stated that the cost for getting a Certificate of Compliance was $700-plus as compared to about $80 if the the job had been done right.

Here is a quotation from a letter from Wellington City Council to an elderly couple who have a new Solahart installation that did not have a building consent. With the help of the Installer, an application for a Certificate of Compliance was submitted:

"Your documentation is being returned because the Council does not accept incomplete applicationsThe following information is needed....:
Provide the application fee of $690
Confirm the system has compliance with NZS 2718
Provide a roof plan showing the proposed location of the panels
Provide fixing details of the panels and the method of making the pipe penetrations through the roofing cladding watertight
Provide two copies of documentations and drawings"

The letter also states that the cost of inspections is $120 per hour.

This elderly couple can not provide this detailed information without the assistance of a plumber and an architect. They estimate the cost will be about $1,500 all up and will take some months to be completed.

In the meantime, their house insurance is compromised by having unconsented work on their house.