The former leaseholder of Rotorua's 'iconic' Blue Baths says new government advice shows the council could have left the building open while a plan was made for its future.

However, Former Blue Baths leaseholder Jo Romanes says now the 89-year-old building has been unoccupied for 18 months, it is no longer in a fit state for the public.

The council says the building is not a priority at the moment and public safety is of primary concern in the closure decision.

In January 2021, the category one heritage-listed building was closed due to concerns about its structural integrity.

It followed an Initial Seismic Assessment that found the building to be earthquake prone at 15 per cent New Building Standard (NBS) - less than a quarter of the standard of a new building.

The NBS rating was later confirmed by a Detailed Seismic Assessment.

The decision was also informed by a swarm of earthquakes in the region on January 25.

Last month, the Ministry of Business, Innovation and Employment released guidance that most seismically vulnerable buildings were not imminently dangerous and could remain occupied while seismic remediation work was planned, funded and undertaken.

In a ministry statement, it says the guidance addressed "common misconceptions around how the New Building Standard should be used" and clarified there is no legal requirement to close a building based solely on a low NBS rating.

Ministry building performance and engineering manager Dr Dave Gittings says compared to most business-as-usual risks, earthquakes are a low probability, and occupancy decisions need to consider the likelihood of an earthquake and temporary mitigation measures that could be employed.

"An NBS rating is not a predictor of building failure in an earthquake and buildings with low NBS ratings are not imminently dangerous.

"Understanding the relative vulnerability of different building elements, potential consequences of failure of these elements, and options to mitigate that risk, is more important than the overall NBS rating for a building."

The statement says buildings with an NBS percentage of less than 34 per cent are earthquake-prone and building owners are required to remediate their building within a specific timeframe, but buildings could remain occupied during that time.

New buildings are designed with a one-in-a-million annual fatality risk due to earthquake, compared to an estimated one in 700,000 for flying a plane or one in 20,000 for driving a car.

The estimated fatality risk in a building under 34 per cent NBS is about one in 40,000 to 100,000.

Former leaseholder Jo Romanes in the Blue Baths in 2013. Photo: Stephen Parker / Rotorua Daily Post.

Romanes says the ministry advice has created a "pathway forward" for owners of low-NBS buildings.

In her view, it provides an opportunity for councils to have a bit more confidence and take more ownership to "just not go around putting fences up everywhere".

When the Blue Baths closed in January 2021, the council told her it was "only interested in zero risk", she says.

"Life is all about risk, it's just about managing it."

She also understands public organisations are wary of liability in case something did go wrong, but in her view the guidance gave councils some licence to take managed risks.

Romanes believed the Blue Baths, which her company operated primarily as an events venue, could have remained open while a plan for its future and strengthening was actively progressed.

"The building was already in a pretty dilapidated state because we were winding down and preparing for revitalisation. The council hadn't done any significant maintenance on it in several years. I'd stopped doing too much as well, as we neared the end of our lease. "

However, now it has been "sitting" for 18 months, Romanes believes it will have "deteriorated more" and will not be fit for the public.

In her opinion: "It is disturbing that the fence has been up for 18 months and the council are quite openly and unashamedly saying they don't have any plan".

She has spent about $250,000 on the revitalisation plans for the building in 2019 "in good faith" and at the invitation of the council, and that resulted in a plan for the building's future, she says.

Upon the project's completion, the building will meet seismic code and operate as a "totally unique heritage venue" with capacity for 1000 people, which Romanes believes will bring great economic benefit to the region.

A resource consent had been submitted and the plan had heritage experts' blessing, she says.

"All that work's been done."

In her view: "The council need to be looking actively at how to fund it.

"This building should be on the list. The work for the way forward has been done, now they just need to take ownership and commit."

Rotorua mayor Steve Chadwick says she's sure the future of the "iconic" building will come to the new council to consider, but "other priorities take financial and operational precedence right now".

She says that includes the Rotorua Museum, also closed and under construction for strengthening and redevelopment.

"The Blue Baths has always been important to Rotorua as part of its visitor destination offering and we'd all dearly love to see it re-opening at some stage."

She says while consideration of the ministry's guidance is an operational matter, she understands decisions to close - or re-open - buildings are "always very carefully weighed up, with public safety at the forefront".

Rotorua Lakes Council organisational enablement deputy chief executive Thomas Colle says the Blue Baths will likely arise as part of the next Long-term Plan, when the council will consider and set the work programme for the 2023-2033 period.

"We are currently focused on other priority projects and work but given its very low seismic rating and taking public safety into consideration, it's unlikely we would consider re-opening the Blue Baths at this time."

Council officers are "always happy to speak with interested parties if they wish to discuss options with us directly", he says.

In July, following the guidance's release, chief executive Geoff Williams says decisions to close buildings are never taken lightly but public safety responsibility are the "primary consideration".

The council relies on expert assessment and has to balance to probability of an earthquake with the "level of potential consequences" if it did," he says.

"In the case of both the museum and the Blue Baths, in making our decisions we considered the level of consequences to be unacceptable."

-Local Democracy Reporting is Public Interest Journalism funded by NZ on Air