Tauranga City Council says it will announce more details about an independent investigation into the Bella Vista Homes saga next week.
Council communications manager Aimee Driscoll said the scope of the investigation, announced by chief executive Garry Poole on Tuesday, would be limited to the Bella Vista Homes at Lakes Boulevard and Aneta Way.
The investigator - to be an external expert - would be asked to proceed "as quickly as possible".
The investigation would be completed before June 6, when elected officials were due to make a decision on what actions the council would take, Driscoll said.
Her comments were in response to questions by the Bay of Plenty Times about the staff responsible for signing off houses that were not code compliant.
The council said on Tuesday that none of the 21 evacuated buildings were up to code. This was despite some having been issued with Code of Compliance Certificates by the council.
Driscoll said that given an investigation was about to start, it was "inappropriate for the council to comment on matters relating to how this situation happened".
"We need to ensure that this is an independent investigation and not influenced by anything we say."