ST. PAUL — A controversial office building envisioned as new space for Minnesota state senators is a step closer to construction.

A Capitol complex governing panel signed off Tuesday on the design, although legal and political hurdles still loom. The three-story building with a glass facade is set to go up across the street from the state Capitol. It was reported that construction could begin this spring and finish within two years.

The Capitol Area Architectural and Planning Board approved design plans for the $63 million office building and a nearby $27 million public parking ramp. It came on a 7-3 vote, with dissenters questioning how it will be paid for.

“I have great concern about moving forward,” said Republican Rep. Matt Dean, an architect from Dellwood who is a planning board member. If building construction starts before the financial and legal issues are resolved, Dean warned “it will be hard to stop.”

Minnesota House and Senate committees must still endorse the design. A legal challenge seeking to halt the project goes before a Ramsey County judge in a couple of weeks.

The building is to be financed through a lease-purchase agreement” in which the state leases the structure from the builder with an option to purchase it. Paying for the lease could require borrowing.

Lt. Gov. Yvonne Prettner Solon, the planning board chair, said the financing is “an issue for the Legislature. Our responsibility is for its design.”

Under the approved design, 44 senators and their staffs would relocate to the new building. The remaining 23 others — Democratic and GOP leaders and committee chairs — would keep offices in the Capitol.

Renderings show the new building has a main floor with large, open public gathering spaces that look out on the Capitol through a “sweeping curve” of a glass and stone wall. It would have larger committee rooms than are available now, which backers say would make government more accessible when hot topics are heard.

A two-level, 265-stall parking garage would be built be built under the building. Because parking is in short supply near the Capitol, the plan also calls for a three-level parking ramp a couple of blocks away.