The building will close to the public at noon on Thursday, December 24 and re-open again on Monday, January 11 next year.
Traditionally, the council's office was closed for the three days between Christmas and New Year, and would have reopened next year on January 5.
Chief executive Michael Ross said the week immediately after New Year was a quiet period for the council.
"This initiative will save the cost of employing temporary staff during the normal year. It seems an ideal time to allow staff to catch up on other important behind-the-scenes work or, alternatively, use accumulated annual leave," he said.
Other council facilities, such as the library, museum, Forrester Gallery, Waitaki Aquatic Centre and the Waihemo Service Centre would not be affected.
Full 24-hour seven-day customer services would be provided by the after hours call service, and a limited number of staff would be on call.
Human resources manager Maree Thompson said some staff found it difficult to take a decent break during the year.
"This presents an opportunity to have an extended period of leave without too much disruption to the public," she said.
Some staff will still be at work during this period catching up on projects.
The extended closure will be reviewed next year and a decision made whether to continue the practice.
