The potential spread of Covid-19 in apartments, particularly ones without windows that open, is raising alarm.
The Ministry of Health released specific guidance for sick people self-isolating in apartments last week, but those who pushed for the advice to be published already want to see it changed.
A key focus of the guidance is about air ventilation and circulation - something that is easy to do if you can open your windows, but less so if you can't.
Many apartment buildings operate a centralised air conditioning and ventilation system, which often recycled air.
University of Auckland aerosol chemist Dr Joel Rindelaub said there was a risk the virus could spread to neighbouring apartments any time there could not be "100 percent fresh air".
"What a body corporate want to do is to try to reduce the amount of recycled air, maybe set up some filtration, to make sure that there can be clean air to breathe," he said.
The guidance states "it is important to ensure that recycled air is not shared between apartments".
But Joel Rindelaub said that was difficult and he thought all ventilation systems in New Zealand need to be improved.
"Apartment buildings aren't set up to be quarantine facilities so there's always going to be a little added risk involved."
The guidance said regular maintenance of ventilation systems was important. It also talked about air cleaning technologies and filters that are available but they were expensive, or usually only used in hospitals, and global demand would make them hard to get.
Zoe, whose apartment in central Wellington did not have opening windows, said it was "disturbing" to think she could get infected because of a shared air system.
But she did not think her building's managers would do anything to minimise the risk.
"They are completely useless with getting anything done, so I can confidently say I would have no faith with them getting anything done around here or if they did it would come at our cost."
Auckland Central MP Chlöe Swarbrick started asking for the advice weeks ago and said it was well overdue.
She said health authorities should be checking that isolation locations are fit for purpose and that problems around air circulation highlighted Aotearoa's "dismal" housing crisis.
"This is why it's so important that we have things like a rental warrant of fitness front-loaded so that everybody knows that the buildings that they are living in are up to standard."
The Body Corporate Chairs' Group helped the Health Ministry develop the guidance. Its vice president, Tim Jones, said people with Covid-19 should not be isolating in spaces with shared ventilation systems.
"And if in fact there is any doubt that there is going to be transmissible air flows between apartments, or from an apartment into an corridor that then ventilates into other units, then the answer is that they should put those people into MIQ," he said.
Jones said the guidance was a good starting point but he already had "a couple of pages worth" of- recommendations for health officials.
"We would just like them to understand that for apartments it's slightly different, or very different in many cases, to putting somebody into a standalone house."
RNZ asked the ministry how concerned it was about Covid-19 spreading through apartment air systems and if it was confident body corporates and building managers would take steps to lower transmission.
But by deadline, a spokesperson had only referred back to the guidance.
