Nelson Mullins Riley & Scarborough LLP plans to move its Boston office to One Financial Center next year, in part to avoid the disruption caused by construction in its current home at One Post Office Square, according to its local managing partner.

The South Carolina-based law firm is taking approximately 43,000 square feet on the 35th and 36th floors of One Financial, the office tower across Atlantic Avenue from South Station, said Peter Haley, the firm’s leader in Boston.

It’s about the same amount of space that it currently occupies at One Post Office Square, where it’s been for most of the decade-plus it’s been in the Boston market. But the Post Office Square building is undergoing a major renovation, including a new-look glass exterior, a large-scale interior makeover, and a significant expansion of rentable space. The project is being co-developed by JLL and Anchorline Partners.

According to Haley, had Nelson Mullins stayed in Post Office Square, it would have needed to move at least once, and perhaps twice, within the building over the short term to accommodate the makeover. The firm’s leaders were wary of that level of disruption. JLL “was great” about trying to find a solution, but the firm “couldn’t quite find something that was right for us,” Haley said.

Nelson Mullins expects to move into One Financial in 2020, potentially in August. Haley anticipates the new space will have about 65 offices, with a more efficient, glass-filled floor plan compared to its current location.

The law firm’s local headcount has changed significantly in recent years. In early 2015, it had 60 attorneys in Boston, but by the next year that figure had dropped to 35 after teams of attorneys left for K&L Gates LLP and LeClairRyan PC.

Since then, however, Haley and the firm’s leadership have been aggressive about wooing partners from other Boston law offices. Its local headcount is back up to 53, according to Haley. The new recruits hail from a variety of firms and practice areas: This year alone, its additions include intellectual property attorneys from Pepper Hamilton LLP and Mintz and a litigator from State Street Corp.

“We’ve had a nice ability to attract lawyers from around the city,” Haley said.

That level of growth is reflected in the firm’s recent financials. In 2014, its $298 million in revenue put it outside the 100 highest-grossing law firms in the U.S., according to American Lawyer Media data. In 2018, it grossed more than $400 million across its more than 20 offices, earning it a ranking as No. 87 in the country.

The new address and new names aren’t the only changes coming to Nelson Mullins. Later this month, Haley is stepping down as office managing partner in favor of his colleague, Brian Moore. Haley has been the office’s leader since 2013 and felt a change in leadership would be good for the future of the firm. He plans to return to his practice full-time, although he will hold onto some managerial responsibilities at the firmwide level.

“The turnover’s very helpful in terms of developing and building leadership within the office,” he said. “Just having one person staying there for 10 or 15 years, I think you miss out on opportunities to build future leaders.”