About 950 homes and commercial buildings are facing a delay in getting final sign-off, says Auckland Council.
The backlog is due to an increase in buildings requiring sign-off, more complex developments and IT issues requiring some manual work, says council's regulatory services director Penny Pirrit.
She said it was currently taking an average of 19 days to process the technical decision for Code of Compliance Certificates, compared with 15 days in March.
To meet the backlog, the council is hiring additional staff with the aim of completing most of the backlog before Christmas, she said.
A Code of Compliance Certificate is the final sign-off for a new building or renovations and is a formal statement issued under the Building Act 2004, that building work carried out under a building consent complies with that building consent.
Building consents general manager Ian McCormick said another reason for the backlog was the council was issuing 700 more Code of Compliance Certificates than this time last year.
He said there had been an increase in the number of complaints by customers about the issuing of the certificates, saying people were keen to get sign-off before Christmas.