Urgent building work is under way at Auckland City Hospital to prepare more rooms for Covid-19 patients.
There were 32 patients in hospital across the region yesterday: 18 in Middlemore, 12 at Auckland City and two at North Shore.
RNZ understands Auckland City and Middlemore are near - or at - capacity for the vital negative pressure rooms that help prevent the spread.
Builders were making alterations to an Auckland City Hospital ward yesterday.
Auckland's three district health boards worked together and shared resources for the Covid-19 response.
All Covid patients in the city were in negative pressure rooms, a spokeswoman said.
"As part of our surge plans, and in line with Ministry of Health guidance, we are also preparing separate, well-ventilated spaces and wards that have been identified as being suitable for isolating Covid-19 patients."
Those were most likely to be used when patients had become less infected, the spokesperson said.
There are 17 negative pressure rooms at Middlemore, but the Ministry of Health said 18 patients were there yesterday.
Auckland City Hospital has 13 negative pressure rooms, and 12 patients.
The DHBs said there was more capacity across the region if needed, including eight negative pressure rooms at North Shore Hospital.
The three DHBs met several times a day to cooridinate the care of Covid patients in the region, the spokeswoman said.