Wellington City Council also blamed its timeliness issues on engineering firms choosing not to renew their services contracts as structural engineers to support the council's consenting function.
The Annual Report said this was "due to the risk of being drawn into third-party claims and their ability to gain insurance or to meet increasing insurance costs for consent work".
A council spokesman said engineering consultancy firms were making their own "judgment calls" on whether they were prepared to take on local authority consenting work.
He confirmed the council has retained the services of some consultancies. The council is also contracting additional external engineering expertise to ensure structural and geo-tech reviews of applications for building consent are not delayed
In a broader context, an Engineering New Zealand spokesperson said there was a growing issue of professional indemnity insurance being more difficult to source.
"This is related to risk, including how it's allocated in contracts, especially in special conditions that are added to standard contracts. This is a sector issue rather than being specifically related to councils."
The latest issue of Engineering New Zealand's EG magazine said Local Government was increasingly being advised by the likes of lawyers to distance themselves from risk by introducing special conditions to contracts.
Pedersen Read managing director Andrew Read said in some instances consultants are unlikely to be able to obtain insurance for this increased scope of liability.
In Christchurch, contractors have never refused to undertake outsourced review work that could not be completed by the city council's own in-house team of engineering specialists, Acting Head of Building Consenting Mark Urlich said.
Wellington City Council has long struggled to meet building consent timeframes.
At the end of 2019 it reported officers were coming under pressure due to a staff shortage and an increasing number of construction projects.
It was so difficult to retain staff that the council applied a market premium rate to remuneration packages for several roles to secure staff in a fiercely competitive market.
The council later accused the Government's new urban development authority of poaching council staff in a "short sighted" and "aggressive" recruitment scheme.
Although at the time, Kāinga Ora said it had only recruited 13 staff from councils for its new Building Consent Authority, all of whom came from Auckland Council.
More new residential building consents have been issued in Wellington City for the most recent year, 1428, than any of the previous four years recorded in the council's Annual Report.
The council's most recent quarterly report suggests the timeframe for building consents is improving as an influx of new staff throughout 2019 have now settled in.
