From Adelaide to Melbourne, Brisbane and Perth, poor ventilation in medi-hotels has been blamed for coronavirus outbreaks and shutdowns across the country.

It has led to calls for national medi-hotel ventilation standards, with critics saying hotel quarantine is not fit for purpose.

But ventilation expert and University of Adelaide academic, Professor Geoff Hanmer, is going a step further.

He wants to see Australia's National Construction Code (NCC) changed to reflect what he describes as "a stack of evidence" of aerosol transmission.

Professor Hanmer is part of the International Code Council's pandemic task force — a global team of experts considering how building design can reduce the spread of disease.

He says the ICC is particularly worried about buildings that rely on doors and windows for fresh air.

"The biggest technical change that needs to be made is the way that we deal with naturally ventilated buildings. That's most aged care facilities or schools," he said.

"When people shut the windows because it's cold outside, there's no ventilation. And the level of ventilation reaches hazardous levels quite quickly."

Can better ventilation stop coronavirus?

The Australian Building Codes Board (ABCB), which sets the NCC, is not convinced that changing ventilation requirements in buildings will stop the spread of COVID–19.

"At this stage, there is insufficient evidence to indicate that a change to the NCC is required or that there is in fact a technical solution available to this form of transmission," a spokesman said.

The ABCB said it was monitoring research into the possible sources of contamination spread within buildings.

Professor Hanmer said there was already plenty of research suggesting COVID-19 was an airborne disease. 

"They're just ignoring this problem until it becomes something which they can't ignore any longer, which is, I think, exactly the opposite attitude that a regulator ought to have," he said.

The chair of epidemiology at Deakin University, Professor Catherine Bennett, said aerosol transmission was evident, and action was needed.

"And yet we still saw cases, where the only explanation is that there is enough virus that's staying suspended in the air for just long enough, for someone to walk in and pick it up."

So, what now?

Some jurisdictions are already making changes.

In South Australia, a dedicated quarantine facility was set up after a state-wide lockdown was thought to have been sparked by poor ventilation at the Pepper's medi-hotel.

Tom's Court Hotel underwent modifications to its air-conditioning and ventilation systems.

"The modifications included improved ventilation and fresh air supply to lobbies and corridors used by staff," SA Health said.

It also required "good ventilation of all occupied areas," and "no sharing of air from guest suites with any other areas".

Professor Hanmer said good ventilation could mitigate the risk of aerosol transmission of COVID–19 and other diseases.

"The health of people in buildings which are well ventilated, particularly aged care, is better," he said.

"The next time this happens when we have SARS-CoV-3, or perhaps a mutation of influenza, we need to be ready and precautionary."

Do we really need higher standards in all buildings?

According to engineer Stephen Giblett, that is a multi-million-dollar question.

"Finances are always a factor," Mr Giblett said.

Mr Giblett said designing buildings with flexible ventilation systems might be the way forward.

"You could actually enable greater filtration in specific circumstances, like a pandemic, and increase the amount of fresh air coming in, so that it just reduces the risk," he said.

On the other hand, Professor Bennett hoped changing ventilation standards in a variety of settings could be a "legacy" of the global pandemic.

"I do think it's something we should move to," she said.

"I think it'll be a combination of retrofit, but also setting codes for new builds, particularly for aged care, or for our quarantine centres … where we now really need to step up our ability to encode safety regulations."