One of the contractors, Holmes Farsight, hired to process consents had been paid nearly $1.3 million since September 2015 when it was not an accredited building consent authority.
Mr Sloman revealed that a second contractor the council had used was also not accredited.
Council chief executive Garry Poole said it was critical to understand the council was the building consent authority, not the companies outsourced to process consents, and the council stood behind the homes consented.
"The public can rely on any consents issued. They are lawful and issued by the council," he said after the meeting.
The meeting was told some council building inspectors had different interpretations for the same building project. It was suggested inspectors be assigned to individual building sites, rather than covering areas of the city.
BDO also revealed the building services department did not follow the council policy that required contracts worth more than $100,000 to go out to the market.
During the meeting, Mr Poole said the non-compliance with the procurement policy was clearly a concern and he has commissioned a forensic examination by accountants Beattie Varley to review the relationship between the council and the company paid $1.286m. He said it was to ensure there was "nothing inappropriate" in the relationship.
Mr Poole said it raised the question of non-compliance in other areas of the council and he has asked BDO to extend its review to the wider issue of how the council procured services.
He said the complaints made by Bella Vista Homes were against wider industry disquiet about the council's performance.
It was revealed that a single building consent application by Bella Vista generated 81 requests for information by building consent processing staff.
BDO said it found no evidence to suggest deliberate obstruction by the council's building services in relation to its dealings with Bella Vista.
The report said the inspection of council consent files did not constitute an audit or forensic examination.
Nor did BDO review every aspect of the allegations or evidence provided by Bella Vista.
"There is no doubt that TCC building department have learnings from their dealings with Bella Vista over the past 12 months."
Bella Vista was now dealing with a single building inspector for its houses. It did not respond to an invitation by the Bay of Plenty Times to comment.
The report recommended the large number of requests for information on applications could be considerably reduced if the council employed skilled people at the front counter to read applications and highlight deficiencies before they were officially accepted.
The clock stopped on the 20-day processing period every time the council asked for information.
BDO found there were inaccuracies in the way the council stopped and started the statutory clock.
A building expert employed by BDO, John Tait, told the meeting more than 90 per cent of applications were being stopped for further information and, in many cases, it was not for detailed information but basic facts.
He said the minority that put in good applications were being slowed by everyone else.
The council received the report.