Work crews could begin ripping up the stately green lawns of the Minnesota Capitol within weeks, after getting a final go-ahead Monday on a full-scale gutting and upgrading of the aging structure.

The Capitol Preservation Committee, led by Gov. Mark Dayton, voted Monday to proceed with the $272 million renovation that could see parts of the exterior being demolished shortly after Labor Day. The project is expected to go on for several years.

“Short-term pain for long-term gain,” Department of Administration Commissioner Spencer Cronk called it, as members of the Capitol Preservation Commission signed off on the plans.

Painful, state officials say, but necessary to preserve a building that was built in 1905. The Capitol’s marble facade is crumbling. The wiring and plumbing are ancient. When it rains, the windows and tunnels leak.

The Capitol has already been swaddled in scaffolding. As the preservation committee looked over details inside, tourists outside were strolling about the lush landscaping that soon will give way to temporary paving for construction equipment.

The design plan approved Monday will make drastic improvements. There will be new public spaces for historical exhibits and staging areas for public tours. There will be glass elevator doors to bring in light and offer breathtaking views of the Capitol interior.

No detail is too small for the preservation plan. The chairs in the House chamber will be upgraded, while its historic voting board will be lovingly preserved. A crumbling outdoor balcony on the second floor will be repaired and reopened to the public. The dodgy acoustics in the House chamber will be improved with a new sound system.

Some of the most dramatic changes will be tucked away behind the walls, invisible but much appreciated by visitors who need to find a bathroom or a Wi-Fi signal. A large chunk of the budget will go to improve deteriorating mechanical, electrical and plumbing systems.

The design plan sets a broad outline for how the renovation will begin. Other major decisions are still pending. In August, the Capitol’s tenants — the governor, the House and Senate and other entities with space in the building — will decide how that space will be divided among them in State Capitol 2.0.

The Senate is hoping to hold on to its offices and hearing rooms in the Capitol, despite the new state office building that soon will be built across the street. The House hopes to be able to carve out some space for its leadership.

Sen. Warren Limmer, R- Maple Grove, proposed creating designated protest zones within the Capitol, to move noisy protests away from lawmakers during votes and legislative hearings. In recent years, large crowds have flooded the Capitol during debates on issues ranging from same-sex marriage to the new Vikings stadium.

“You cannot do business with a raging mob outside your door,” Limmer said. “You have to get through, sometimes, some very hostile people. I see where people have been hit with placards and signs and spit on … We don’t want to deny anyone’s freedom of speech, but there is a limit.”

One of the biggest challenges of the renovation will be preserving access to the public throughout the project. The Legislature will continue to meet in House and Senate chambers. Planners are taking pains to minimize damage to the Capitol grounds — exactly one tree will have to be felled during the project, they predict. Dayton, as a member of the preservation commission, urged construction crews to keep the Capitol looking as nice as possible during the three- to four-year project.

Keep it clean

“Construction sites are notorious for their debris — used coffee cups and soda cans and everything,” Dayton said, urging planners to lay out the construction areas, including placing portable toilets out of “the sightlines to the Capitol.”

The first major demolition work is set to begin in September. The wiring and plumbing work will begin in January 2014. Renovations on the north and west wings are scheduled to begin in the summer of 2014, while east wing renovations will begin in June 2015. The entire project is scheduled to be complete by December 2016.

Dayton, who is among the Capitol tenants who will be evicted from his office during the construction, said he and everyone else caught up in the construction headaches will have to “grit and bear it.”