Major portions of the State Capitol building, including its rotunda, will close to the public next week as the years-long restoration project enters its next phase.

The Department of Administration announced Thursday that work would become much more visible after the July 4 weekend passes. Among the projects getting underway are the replacement of the roof, and prepping much of the building's interior for new mechanical and electrical system installation.

That means closing off the rotunda, every floor of the building's east wing, and the ground and first floors of the West Wing. Administration officials said those spots need to be closed off both to protect the public and architectural features.

"The interior and exterior of the Minnesota State Capitol is a live construction site," said Department of Administration Commissioner Spencer Cronk. "We have a once in a lifetime opportunity to preserve this beautiful building for the next century, but with that opportunity comes shome short-term inconveniences. There will be a lot of noise and detours."

Many of the building's most prominent tenants have already been moved off site. Gov. Mark Dayton and his staff moved to the Veterans Services Building at the south end of the Capitol campus. Attorney General Lori Swanson and her office relocated to office space in downtown St. Paul.

The only tenants remaining for now are state senators with offices in the building. They'll be moved out after the 2015 session.

Most of the building's art has been removed and is being stored by the Historical Society. Flagpoles from the top of the building have been taken off to make room for the roof replacement, and the golden chariot sculpture at the base of the dome will be enclosed to protect it during construction.

The $273 million renovation and repair of the Capitol is scheduled to finish up in 2017. It was initiated with a focus on repairing deteriorating exterior stone, addressing safety concerns in the aging building, replaced outdated systems and creating more public space.