The major renovation and expansion of the Minnesota State Office Building (SOB) will begin next week with site preparation just to the north of the building, where the major expansion will take place.

A spokesman for the Department of Administration says the first phase will also include closing the tunnel between the SOB and the State Capitol building and the closure of the north entrance to the building.

Once the 2024 legislative session ends in May, the SOB will be closed completely to allow renovation to begin on the interior of the existing building, including HVAC systems, security enhancements and accessibility improvements. The expansion will add about 166,000 square feet to the 290,000-square-foot building.

The news of the project’s start comes a day after Republicans tried one more time to stop the project and scale it back. The $500 million dollar project will climb to $730 million with interest on bonds. A new Senate Office Building cost $90 million in 2016 and renovation of the entire State Capitol cost $310 million.

RELATED: State Office Building renovation and expansion to start next month despite growing cost

Representative Kristin Robbins(R-Maple Grove) made a motion in the House Rules Committee on Wednesday to stop the project.

“The chair of the committee on rules and legislative administration is instructed to inform the governor and the commissioner of management and budget that the House of Representatives as primary tenant no longer approves of this project,” Robbins said in reading the motion.

However, DFL Majority Leader Jamie Long, the chair of the committee, ruled her motion out of order because it wasn’t submitted before the meeting. So there was no further debate on the project.

“The scope and scale of this project which was approved in a lame duck Rules Committee session last year that now has encumbered the taxpayers with $730 million dollars for one building is unconscionable,” Robbins said after her motion was denied. “I can’t fathom we’re going to go ahead with this, members. I’m just asking you to pull back.”

Democrats say the building needs updating for safety and security. They say the expansion will increase meeting space and accessibility for the public.

When the building closes after the 2024 session, House members and agencies that use the SOB, like the Secretary of State, will have to be temporarily relocated until it reopens in 2026. There is no cost estimate for that yet.