The first pop-up library space in central Wellington will open at the end of next month, but not before 45,000 items are due back on May 1.
It follows the sudden closure of the capital's Central Library on March 19, after an engineers' report found the building had "structural weaknesses" that could compromise the building in the event of a "significant" earthquake.
On Wednesday, Wellington mayor Justin Lester said the first pop-up library space would open at 12 Manners St in "late May".
Customers would be able to borrow, pick up reserves and return books at the pop-up location.
The council confirmed that 45,287 items were currently on loan, and all items borrowed from the Central Library were due back on May 1.
Councillor Fleur Fitzsimons, community facilities portfolio holder, said the council was not anticipating that an influx of returns was going to be an issue, but that it would be "closely" and "constantly" monitoring how the branches were coping.
"My understanding is that we have already had a high rate of returns, much higher than usual.
"The key priority is to make sure that it is smooth and easy for residents to continue using the library."
There was no desire to take a "punitive" approach to late returns and she said people should continue to bring books back when is convenient to them.
The Manners Street pop-up was expected to be the first of a network of CBD library services, and details of other pop-up locations and services would be announced in the coming weeks.
It is anticipated the pop-up service hours will include late nights and weekends.
A small range of seats for reading, study and work, along with free WiFi and some printing, photocopying and internet access facilities would also be available.