Despite months of protests from residents, the Boston Zoning Commission unanimously approved plans for a 47-story tower with condominiums and retail space at Copley Place, paving the way for to start construction in the fall 2012.

Following a three-hour meeting heavily attended by those both supportive and opposed to the project, Chairman Bob Foundren called the building “elegant and sensitively designed for it’s location.”

“It is a tall building, but it’s not big and bulky…” he said. “It does the least damage on the site that a building could do, and it enlivens a section of this city that I think badly needs it.”

The $500 million expansion includes 70,000 square feet of new retail space, restaurant space and a public atrium, including 115,000 feet of expanded commercial space and a massive renovation to the existing Niemen Marcus department store.  A 47-story residential tower containing 318 units would take over the brick plaza at the corner of Dartmouth and Stuart streets and rise above the existing commercial building, becoming the tallest residential building in Boston at 625 feet.

The project is expected to create 1,700 construction jobs and 270 permanent jobs once completed. It will also generate approximately $7.2 million in annual property tax revenue.

“I’m not surprised,” said Ken Kruckemeyer, part of a group of about 80 residents who have protested the tower throughout the process, said of the approval. “The city is well wired, but we firmly think the legal issues are real.”

The group has brought up concerns about the length of shadows and amount of wind such a building would create, and what's allowed under the zoning, and called the luxury housing “non inclusive” and “segregating” to local residents.

Of the 318 residences, 48 will be affordable. The developer originally planned to construct only 10 on-site, but agreed to include the rest after hearing neighborhood concerns.

Residents also pushed Simon Property to expand its 15 percent affordable housing to 25 percent, saying a requirement from a 1980 grant should be honored “if not by law, then in spirit.”

Simon Property said the 99 lease it signed for air rights with the Massachusetts Turnpike Authority – a lease that many felt was rushed through and approved before final recommendations had been submitted – contains many more obligations to the city.

The developers also provided a list of  “benefits” contingent with the project, including $1 million to support public art in the city, $1 million in traffic improvements, $250,000 to the Friends of Copley Square, and $250,000 to improve the section of the Southwest Corridor between Harcourt and Dartmouth Streets.

"I think it was the right decision," said Meg Maizner-Cohen, President of the Back Bay Association and a member of the Citizen Advisory Committee - a diverse group of businesses representatives, residents and others involved with helping to establish the details of the project.

During 19 meetings she said she watched as developers responded to concerns, and believes it's in the best interest of the neighborhood and the city.

"It was a long community process," she said, "where I think every issue was aired."