The charges relate to the defendants allegedly carrying out building works which were not in accordance with the Building Act, in particular a building consent.
On February 2, 2018, Rose McLaughlan was brought in by the council to assess each Lakes Boulevard and Aneta Way home for defects, subsequently leading to their evacuation.
Sparrow yesterday read a supplementary formal statement to the court and said building consents and amendments to restrictive building work were unable to be approved retrospectively.
Amendments and minor variation changes to the building work needed to be approved by the Building Consent Authority prior to work commencing, he said.
"My view is that over-excavation could be considered a defect or mistake. The issue here is that nothing was done to make any amendment to the consent to rectify the situation.
"No design was undertaken for the change and no approval was given for the change."
He said the absence of timber retaining walls at some of the properties had "a knock-on" effect causing over-excavation, masonry retaining walls being higher, buildings incorrectly located and driveways that are excessively steep.
Sparrow also said in his view the over-excavation on the Bella Vista Homes subdivision could have contributed to the alleged defects at the centre of the charges.
He said there were "many opportunities" where council staff had options of issuing a notice to fix when alleged faults were identified.
"From witness statements I reviewed, several stated that senior council management wanted staff to work with the developer rather than issue a notice to fix," he said.
However, Sparrow said in relation to two of the houses, Cancian was requested multiple times to undertake sediment control and protect surfaces from erosion.
Under cross-examination, Cancian's defence counsel Bill Nabney put to Sparrow that there were at least two instances where identified issues were fixed after council inspectors signed off on changes to building works on site.
Sparrow conceded documentation had been stamped "minor amendment" and approved.
But he said that was not best practice and also not line with the legal requirements in terms of building consent process under the Building Act.
The trial continues.