The noise from major construction is upsetting patients at Auckland City Hospital, who are being offered earplugs to block out the banging and crashing.
The family of one patient who gave birth to a boy on Tuesday said the noise was unacceptable.
The new mother is on the 10th floor of the hospital, and was struggling to get sleep during the day while builders were working.
"The construction work goes on from 7am to 6pm every day. It's an hour on and then an hour off. They are handing out earplugs to patients," said her sister-in-law, who did not want the family identified.
"As you can imagine for a new mum with a newborn, sleep is the most precious thing. But they are not getting it."
The sister-in-law said hospital staff told her that at least three complaints were being made each day about the construction.
"They suggested the family make a formal complaint to the consumer liaison team," she said.
The patient had yet to lodge the complaint.
"The reality is they can't close the ward as it's too costly, but sleep is precious when you are in hospital."
An Auckland District Health Board spokesman said the construction project was a new unit for haematology and bone marrow transplant patients, and acknowledged the noise was not ideal for them.
"The present unit lacks space in general and the family space in particular necessary to support patients who often experience long stays," they said in a statement.
"The main impact has been on the Tamaki post-natal ward. Patients with high-risk medical issues related to their pregnancy are cared for elsewhere and not affected by the noise. The post-natal patients tend to be in the Tamaki ward for between one and three days following delivery."
Construction was scheduled "during normal hours" from 8am to 5pm.
"There have been no formal complaints, though patients have complained to ward staff.
"We try to keep patients fully informed and when they have the context for the noise, they often are better able to cope. Patients can request ear plugs."
The spokesman said the construction worrk was necessary, and the DHB had done enough to "protect the comfort and health of patients".