"The library bus at the market, as the father of two kids who rush in there, it's just a boon and we don't want to diminish it in terms of size restrictions, how available the library is to a lot of kids," he said.
"My expectation is a lot of thought and a lot of effort will go into making the children-focused van utterly welcoming for kids and a place where they can actually sit and read."
The mobile library has 26,000 visits a year and issues 36,000 items.
One van will focus on visiting remote areas and underserved suburbs while the other will visit schools and other educational organisations.
"There's going to be a lot of users of it, including the elderly, so I'm sure it's going to be looked at carefully and it will be designed carefully," councillor Helen Craig said.
The current library bus began operating in 2003 but the "vehicle's mechanical unreliability is now compromising the delivery of the service", a report by council libraries and community manager Pete Gray said.
Gray said the new vans would provide walk in space and have some seating.
He said, the new vans would not require a heavy vehicle licence which would cause fewer problems when staff fell ill.
Council has budgeted $300,000 for the two vans with supply and fit-out going out to tender.
The bus will be sold.
