Senators have approved a $77 million office building across the street from the Capitol that will serve as their primary workspace, endorsing a move by their House colleagues to scale back some amenities while boosting overall space in the complex.

The Senate Rules Committee signed off on the project Monday. The panel previously backed a version of the same project, but the House Rules Committee approved an altered version last Friday. In addition to ditching plans for a parking ramp, reflecting pool, a workout room and elaborate landscaping, House members also moved to increase the total number of senators' offices from 44 to 67 so that every member of the Senate can be housed there.

Adding office space contributed to the cost of the building, but by dropping the parking ramp lawmakers were able to achieve net savings in the overall cost of the project, which had originally been estimated at $90 million.

Republican lawmakers have been vociferous critics of the legislative office building, calling it wasteful and unnecessary and vowing to use it against Democrats in the next election. But its backers, led by Senate Majority Leader Tom Bakk, have called it the most cost-effective option for housing senators during and after a major renovation of the Capitol building.

Under current renovation plans, senators are likely to be moved out of the Capitol after the 2015 legislative session. Once the building reopens in 2017, a large portion of space now occupied by senators is set to be turned over to the governor's office, the House and the Minnesota Historical Society.

The Senate Rules Committee approved the retooled office building projects on a party-line vote, with the committee's eight Democrats in favor and five Republicans opposed. Before construction can start, a panel of state officials overseeing the Capitol renovation project must sign off on the plans. A lawsuit challenging the building plans, filed by a former Republican state representative, is currently pending before the state Supreme Court and also threatens to slow down the construction timetable.

The building site is directly north of the Capitol on the other side of University Avenue. Planners hope to have it ready for senators and their staffs to move in by late 2015.