What was "unusual", however, was the idea from Bella Vista management of leaving the construction of retaining walls for homeowners to take care of. This became a problem for council inspectors who discussed the matter at length with Bella Vista management "many times", he said.
Sparrow said there should have been retaining walls in place before construction of the homes, which would have helped with sediment and erosion control. However, the lack of retaining walls was just one of a "multitude" of problems with the Bella Vista site, he said.
"When going on-site to check, council [inspectors] has been overwhelmed with those more global issues rather than focusing on others," he said.
"There were significant other issues that were being focused on rather than the specific technical work."
Sparrow said, in his view, the council inspectors ought to have seen and observed key issues but failed to do so early on. Other issues already detailed in the case include the alleged lack of painting or primer on pieces of timber, inadequate weather tightness and misplaced or missing reinforcing steel.
"No Notice to Fix was issued until much later in the piece when homes were either near completion to had been completed. In my view, Notices to Fix should have been issued at an early stage," he said.
Sparrow said, in many cases, structural matters, retaining walls and ground-bearing issues were usually assessed and signed off by a third party, not a council inspector. This was usually an engineer who signs a PS4 (producer statement construction review) which then acts as a guide to the council indicating compliance.
"Therefore, they rely on engineers," he said.
"Producer statements aren't covered in the Building Act but are commonly used in the process and documentation in all councils in New Zealand. The production statements system aims to give BCA [Building Consent Authorities] reasonable grounds without having a double-up.
"This is for reasons that those are highly technical areas. Councils often do not have the capacity or capability to do them. In Tauranga, it's quite common for inspections of blockwork to be quite cursory."
Sparrow said it was clear Cancian had taken a number of different roles at Bella Vista Homes subdivision.
The court heard Cancian was the licensed building practioner (LBP), supervised physical work on-site, signed Records of Work, was considered to be a building contractor and was also involved as an on-seller.
He said a developer being involved in so many roles was "usual".
"Mr Cancian had a large part of play in significant decision making ... and had an instrumental part to play in the eventual failure of the development.
"It appears Mr Cancian was the ultimate decision-maker."
The trial continues.