A Ministry of Health spokesperson said the Energy Centre building is being constructed concurrently with the biomass boilers and associated fuel handling systems and pipework.
The centre will service the main hospital campus as well as the new Waipapa building.
The total budget is $44.4 million - funding was drawn from the Earthquake Repairs Programme of Works, which was established with insurance settlement funds.
The project was first announced in early 2019 and expected to be completed by the end of 2020 or early 2021.
The spokesperson said the project has suffered some delay due to the impacts of Covid-19.
The existing boiler house at the Canterbury DHB's main hospital campus was damaged in the 2011 earthquake.
It is at an increased risk of failure in the event of another significant earthquake, the spokesperson said.
"This investment will ensure the critical energy supply for the hospital and Canterbury DHB's main hospital campus is resilient, reliable, modern and environmentally sustainable.
"The new boilers will use sustainably produced wood biomass, which is a renewable resource and affordable. The boilers are a great way to dispose of waste wood, and will emit far less carbon dioxide than conventional fossil fuels."
At the time of the announcement, then Health Minister David Clark said the project will ensure the critical energy supply for the hospital is modern and reliable.
"This is a key piece of the hospital's infrastructure. Staff and patients need to know the energy supply can be relied on. This investment will give them that confidence."
"The design and construction of the two 7.5Mw capacity biomass boilers is a key next step towards building the new Energy Centre, which is needed to service the new Christchurch Hospital, Hagley (formerly known as the Acute Services Building) and all of Canterbury DHB's main hospital campus.
"Once the design of the boilers has been completed, then the design and procurement of the Energy Centre building can take place."
