As the Hennepin County Library system nears the 10-year anniversary of its merger with Minneapolis city libraries, officials are looking at a new way of deciding when to revamp the system’s buildings.

The 2008 merger boosted the number of libraries in the Hennepin system from 26 to 41, making it the state’s largest. Since then, the county has had the goal of updating each of its libraries every 12 years.

That’s led to the unveiling of new library buildings, such as those in Brooklyn Park and Webber Park in Minneapolis, and renovations of buildings such as the Ridgedale Library in Minnetonka, where construction starts this month.

But library leaders told the County Board last month that it may be time to change that policy.

Renovating libraries based on the building’s use, instead of an automatic revamp every 12 years, could be more efficient and possibly less expensive over time, they said. It might also ensure that patrons get the same experience no matter which library they visit, from downtown Minneapolis to the outer-ring suburbs.

“We just had to get ourselves on a schedule; it was a good first step,” said Lois Langer Thompson, the library system’s director. “But is that the best way? It took us that long to understand how the buildings are used.”

In June, the County Board directed library officials to come up with criteria for a new plan on how to determine which libraries should be renovated and develop that plan by the end of this year. Library officials will report on how they will evaluate library use and which libraries should be next up for a makeover.

Hennepin County is one of the largest library systems in the United States, serving 1.19 million people. On a per capita basis, Hennepin has the third-most books — 4.2 million — and the fourth-most library branches in the nation. It has an annual budget of $83.9 million.

People aren’t just going to libraries to check out books. In 2016, according to the library, there were 2.2 million downloads of books, movies and music — up from 1.5 million downloads in 2014 — and nearly 23,000 reservations for meeting rooms.

The Minneapolis Central Library in downtown even has a full-time social worker, helping connect homeless visitors to resources.

“Libraries are changing,” Thompson said. “They are different kind of spaces. We want to be able to respond to that as well.”

While the merger with the financially strapped Minneapolis system was controversial at the time, it has helped the county renovate and reopen libraries. The county’s libraries span 124 years, from the oldest, Pierre Bottineau in Minneapolis, built in 1893, to the newest, Webber Park, which opened in May.

Of the system’s 41 libraries, those that get the most visits are Minneapolis Central, which had more than 1 million visits in 2016; Brookdale, Brooklyn Center (422,171 visits); Southdale, Edina (303,316 visits); Ridgedale, Minnetonka (297,024 visits), and Maple Grove (259,246 visits).

“We want to keep moving our libraries in the future and keep meeting the community’s needs,” Thompson said. “I’m really excited about the opportunity this will provide us.”