Work will begin next week on the upgrade of the Winter Gardens at Rotokawau Virginia Lake.
Formally known as the Centennial Winter Gardens, they were opened in 1940 to mark 100 years since the signing of the Treaty of Waitangi.
From Monday visitors to the Winter Gardens will enter through a signposted alternative access while the entrance way is upgraded.
Project officer Debbie Anderson said the alternative access would be used from Monday to Friday, with normal access available during the weekends.
The work on the entranceway is for earthquake strengthening. It is expected to be finished by Friday, June 11, 2021.
In August the gardens will be closed for six weeks while the building's interior is repainted.
"The Winter Gardens are a much-loved part of Rotokawau Virginia Lake, and it's important they are kept looking their best," Anderson said.
The Winter Gardens are an art deco-era conservatory and outdoor area known for their colourful tropical plants and themed gardens.