The NSW Building Commissioner, who withdrew his resignation after his minister was sacked, has detailed the concerns he raised about her performance.
David Chandler tendered his resignation in July, pointing to his "problematic" engagement with the office of the state's former fair trading minister Eleni Petinos, who was left the job later that month.
On Wednesday, Mr Chandler said he thought Ms Petinos wasn't as "invested" in implementing legislation designed to address building non-compliance and serious defects as her predecessor, Kevin Anderson, causing confusion in the building industry.
His resignation letter had also stated his concerns about a relationship between Ms Petinos and Coronation Property Group.
Mr Chandler had delivered a draft stop work order to the developer's architecture firm when he received a "prompt" call from Ms Petinos' chief of staff, followed by a text message from former deputy premier John Barilaro, who worked for the developer at the time.
"I thought, within an hour of issuing the draft order, (that) was pretty prompt," Mr Chandler told a budget estimates hearing on Wednesday.
However, Coronation did not push back on the order, telling him it had taken people off the job because "they weren't doing it right", before apologising and pledging to fix the issues raised, Mr Chandler said.
Department of Customer Service secretary Emma Hogan told the hearing Mr Chandler didn't ask her to investigate further, after telling him she found nothing untoward.
Ms Petinos had previously asked Ms Hogan to conduct a separate investigation into whether Mr Chandler had misled parliament, which she found he had not.
However, her investigation into Mr Chandler and a "communications mishap" over a briefing he gave non-government MPs, which upset Ms Petinos, may have "tipped him into resignation".
"But the broader issue was that he felt that the minister didn't have faith in his agenda ... as a result he also didn't have faith in their relationship," Ms Hogan said.
Premier Dominic Perrottet says a "peripheral" conversation about Mr Chandler's resignation letter occurred during a meeting the day he sacked Ms Petinos, but he did not read the letter and Ms Hogan said it had already been appropriately dealt with.
"I can assure you nothing arose in the course of that discussion that had any bearing or impact on my decision," Mr Perrottet told a separate estimates hearing on Wednesday.
Issues were already being informally raised about Ms Petinos in April, following her brief promotion to cabinet in December.
"One was concerns about respectful behaviour in meetings and others about some cultural concerns that had been raised with me about working in her office," Ms Hogan said.
"There was some (departmental) staff who did not wish to work in that office."
Ms Petinos had her own issues with some staff, Ms Hogan said.
"On occasion it was considered that we perhaps hadn't put the right skill set or right person in there, so I would say that was two-way," she said.
Customer Service Minister Victor Dominello, who took over Ms Petinos' portfolio, says he never received any formal or informal complaints.
He was told of issues in her office by the premier in early July.
"She did not have much staff on deck at the time and that was slowing things down," he said.
"(The premier) asked me as a senior minister, if I could reach out to her ... I said 'why don't we have regular coffees once a week so you can go through any issues or challenges you've got'," Mr Dominello said.
She was sacked before they could have their first coffee.