Plans for a major expansion of the Bal Harbour Shops crossed a significant hurdle this week, when the Church by the Sea members approved the idea of relocating the church from its current location surrounded by the mall.

While no deal has been finalized, the congregation on Sunday agreed to what amounts to a theoretical land swap with the owners of Bal Harbour Shops. The mall’s owners would get the church land to use for expansion and in exchange would pay for the costs of building a new church on what is now a small portion of the mall’s parking garage. The new church would be at Bal Bay Drive and Park Drive at the mall’s northwest corner.

“It’s a monumental vote and a meaningful step in the right direction,” said Matthew Whitman Lazenby, Bal Harbour’s operating partner and the third generation of the Whitman family to run the business. “We’ve literally been waiting on this for decades. My grandfather always knew that piece of land would be critical to our future success.”

Church officials declined to comment on the vote or any negotiations with the Bal Harbour Shops.

Lazenby’s grandfather, Stanley Whitman, has been trying to acquire the church land at least since the mall opened in 1965, if not before. Negotiations grew more earnest eight years ago and really picked up intensity in the last four years.

The arrangement with the church has been the initial barrier to moving forward on an expansion plan the owners of Bal Harbour unveiled in March 2011. This would be the first major expansion since the luxury shopping destination added a second floor in 1982.

While the need for a potential expansion has been discussed for years, the impetus was driven home recently as Bal Harbour’s dominance of South Florida’s luxury retail market has been challenged by the relocation of tenants to the Miami Design District. Bal Harbour still remains the top producing shopping center in the country with average annual sales for the 12 months ending in April of $2,511 per square foot, a nearly 25 percent increase over the same period last year.

“The timing here is perfect,” Lazenby said. “We’re reporting our best numbers in 50 years.”

Finalizing the deal with the Church by the Sea involves negotiations over the detailed plans for building the new church, which would be at least twice the size of the existing location, Lazenby said.

“They specced out the church in a way that makes sense to them,” he said. “Now we have to make sure the specs are mutually acceptable.”

The deal also includes financial compensation to the church in exchange for the option rights on its land, Lazenby said. But the church requested he not disclose the amount.

Lazenby hopes to have a deal completed with the church in the next month, so he can present expansion plans to the Bal Harbour Village Council sometime later this summer.

Those plans still call for another 100,000 square feet of small retail space to allow for about 50 new luxury retailers, plus a 90,000-square-foot specialty department store that could include Bergdorf Goodman, Barneys New York or Bloomingdale’s Soho. Despite some community objections, plans for a Cobb Theatres CineBistro, an upscale movie theater, and an event space by Barton G both still remain, Lazenby said.

“It’s not our intent to force down somebody’s throat something that people don’t want,” he said. “Those are uses that we intended to add value to the community. To the extent that the community doesn’t want them we’re not going to do it.”