A list of the country’s least energy-efficient councils includes the Dunedin City Council and Central Otago District Council, both of which last year declared a climate emergency.

The Dunedin City Council says the assessment by the New Zealand Green Building Council is limited, relies on incorrect assumptions and only considers a 40-year-old building that presents challenges concerning energy efficiency.

The Central council says it does not take into account the challenges of small ratepayer bases or the range of sustainable measures already introduced.

The building council has assessed the public buildings of about 70 councils around the country.

Building information and energy data obtained under the Local Government Official Information and Meetings Act was used to rate the councils’ public office spaces.

In the results, released this morning, it listed what it says are the 11 worst-performing councils as regards energy efficiency.

They include five southern councils — Central council, which the building council says still burns coal; Dunedin City Council; Gore District Council; Invercargill City Council and Westland District Council.

Dunedin City Council group property services manager Dave Bainbridge-Zafar said the building council’s assessment was only referring to the Civic Centre building, rather than all council facilities or activities.

‘‘It makes incorrect assumptions, including around the number of computers in this building and that the building is only in use 48 hours a week.

‘‘In reality, both figures are significantly higher.’’

The city council was actively working to make sustainability improvements across all of its buildings and the city, he said.

Reducing waste and emissions impacts, reuse and sustainability were important considerations when council-owned buildings were upgraded and built.

The 40-year-old Civic Centre, like all old buildings, presented challenges concerning energy efficiency and the council was assessing how it could improve its operational and environmental performance.

It was also assessing a range of clean-heating options for council-owned buildings in the Octagon area, as well as Moana Pool, in conjunction with other large city organisations such as the University of Otago and Southern District Health Board.

‘‘The DCC is working to improve our environmental impact, address climate change, and reduce carbon emissions in all the work we do for Dunedin.’’

As part of its 10-year planning work, a review was being done to ensure all council activities were as aligned as possible with its net carbon zero 2030 target, Mr Bainbridge-Zafar said.

Central council chief executive Sanchia Jacobs said her council took on board the feedback.

‘‘That said, the NZGBC has the luxury of viewing the world through a single lens, without the trade-offs between different, and often competing outcomes, that councils must consider.

‘‘This is particularly so for small rural councils like ours who have limited resources and constrained budgets. Prioritisation and phasing of projects is a must.

‘‘Finding money for new cuttingedge building fit-outs is a challenge when you have a small ratepayer base, and also have to prioritise office spaces over community spaces/projects.’’

The council had adopted a sustainability strategy.

It had also installed publicly accessible electric vehicle charging stations, introduced hybrid vehicles to its fleet and replaced streetlights with LEDs, among other things.

It was investigating replacing the coal-burner at the William Fraser Building, that houses its Alexandra offices, with a more environmentally friendly option.

Building council chief executive Andrew Eagles said it had been ‘‘forced to expose these councils because transparency about how our public buildings perform is non-existent’’.

He urged councils to use the National Australian Built Environment Rating System New Zealand energy performance scheme to formally benchmark the performance of their buildings.

“We know benchmarking and being transparent is key to improving energy efficiency, reducing the environmental impact of our buildings, and improving the health of New Zealanders. If we don’t measure it, we won’t improve it.”