Reed Smith L.L.P.’s Philadelphia office is set to move its 320 lawyers and support staff from One Liberty Place to new quarters at Three Logan Square.

When the move is complete March 3, firm leaders say the firm will occupy about 20 percent less space in a reconfigured office with greater energy efficiency and more opportunities for collaboration.

“Aside from the burden of unpacking, we are excited about having brand-new surroundings,” said Leonard Bernstein, managing partner of the Philadelphia office.

The move is in keeping with a trend among law firms to use smaller spaces that reflect current thinking on how best to promote collaboration among staff while also conserving funds.

Individual attorney spaces will be smaller at the new offices. With so much legal information now available online, the law library will be smaller, too.

“The entire delivery of legal services has changed,” Bernstein said. “There is less need for library space and less need for large offices. People work from home and they work remotely.”

Reed Smith said that the energy-efficient design is projected to save the firm nearly $2 million in electricity costs over the 16-year lease.

Reed Smith, with 1,800 lawyers  worldwide, including 358 in London, its largest office, said it will occupy six floors at Three Logan comprising about 130,000 square feet. The new offices will include a moot court that also can double as a Pilates room.

The firm said the transition would start Saturday with the move of library and case files, and information technology staff.

A second phase begins Friday, when the office’s remaining computer hardware, including hundreds of personal computers as well as copiers and printers, will be moved.

The firm won accolades on Capitol Hill in January for the energy-efficient design of the office space. Rep. David McKinley (R., W. Va.), in testimony before the Energy and Commerce Committee, cited it as a “Philadelphia success story” in testimony on a bill to promote energy-efficient buildings. [email protected]