Despite the drawbacks, Batty said the due date for completion of the redevelopment is still on target for March 2023.
"Of course, we are dealing with the unknown impacts of Covid-19 and supply issues," she said.
Councillor Helen Craig asked Batty for clarification on whether the target completion date would also be the opening date.
Batty said March 2023 is the anticipated date for the conclusion of work and the opening would be held at a later date.
She said significant progress had been made in all areas of the project with foundation and flooring work completed in the west and east quadrants of the existing building.
"That has allowed works to progress in the southern quadrant with a lot of sand taken and removed from the site, to be returned for use as backfill around the new wing," Batty said.
"The northern quadrant has presented the contractor with the additional challenge of needing to install ground beams and steel reinforcing into a more constrained basement space, made necessary after the level of the new ground beams had to be raised to compensate for the shallowness of the existing foundations."
Old concrete in the central dome area had been demolished and removed and drainage works were completed before site concrete was placed.
Batty said the construction tent that was erected over the new extension wing, Te Pataka o Sir Te Atawhai Archie John Taiaroa in November had allowed construction work to continue during heavy rain in December and the work had reached a significant milestone.
"The basement floors and walls for the collection storage facility, and the ground floor
of the new wing's three-story tower block are now complete," she said.
Tihei Ltd had been appointed to work with Tupoho to guide the creation of the cultural expression for the new wing.
They have been working with the architect and a local iwi artist group led by Cecelia Kumeroa on the cultural design concept for the Pataka which includes the façade and entrance area.
"This is an exciting time for Tupoho and a successful design outcome for the Pataka is critical to ensure community and stakeholder aspirations are fulfilled," said Batty.
Batty said once the design elements for the Pataka have been developed and approved by mana whenua through Te Rōpū Kaitiaki, the architect will create the design documentation for costing.