However it seems the database may hold much more than just information about property transactions. The Department of Building and Housing (see reference below) describe it as having a use in Green Zone areas:
Insurers, their Project Management Organisations (PMO’s), Building Consent Authorities, designers and builders will have access to the Canterbury Recovery Orbit website, as necessary. This will enable access to Technical Category and existing geotechnical information specific to the site, provide a means to enter geotechnical data collected and facilitate building consent applications.It seems likely the databases mentioned by CERA and the Department of Building and Housing are facets of the same thing.
As CERA is gathering and storing geotech and other information at the individual property level, it should be available to residents as well as those on the other side of negotiations. Useful also to those wishing to challenge zonings, or at least to better understand them.
The DBH quote is from: P5, Sec. 3.1. Preview of the update to: Guidance on house repairs and reconstruction following the Canterbury Earthquakes, on the Department's website here: http://www.dbh.govt.nz/earthquake--reconstruction-guidance-preview