IRVINE — Plans for nearly 5,000 new homes ringing the Orange County Great Park won preliminary approval from a divided City Council last week.

Irvine officials voted 3 to 2 on Tuesday night to OK general plan and zoning changes and $40 million in park infrastructure improvements.

The general plan amendment concentrates homes in the northwestern area of the project and allows mixed-use neighborhoods of 4,894 residential units and more than 1 million square feet of nonresidential space.

Mayor Sukhee Kang lauded the homes project as an economic stimulus that will "define the future of Irvine."

In addition to homes and condominiums, Aliso Viejo-based developer FivePoint Communities' plan includes parks, shopping areas, trails to the Great Park, a school, a police substation and other amenities, according to a presentation by city staff.

The project is estimated to bring 16,510 jobs to the area, Kang said.

"This project is complementary in nature for us," Kang said. "To be successful, we need the FivePoint Communities' Great Park Neighborhoods to be successful as well."

The single agenda item also covered the first reading of a city ordinance to create a new zoning designation for areas of the project that emphasize residents' abilities to use public transportation or walk and bike to shopping, work and school.

The ordinance for the new zoning district, which is called the Trails and Transit Oriented Development, will come back before the City Council for a second reading Tuesday.

Despite voting against it, council members Beth Krom and Larry Agran expressed their desire to see the homes project move forward.

Krom said she did not feel prepared to cast her approval due to "incomplete information."

"Zone changes are a pretty big deal," Krom said. "They're not a minor issue. Once a zone change is in place, it's fixed. There's no further opportunity to go back and revisit it."

While the terms laid out in an adjacent landowner agreement are intended to alleviate issues caused by the zoning change, such as roads being built through land intended for the Great Park's planned Upper Canyon feature and potential delay in the development of infrastructure, Agran described it as "half-baked."

The agreement is intended to protect the public's use and enjoyment of the land, he said.

"For my purpose, there needs to be more in that agreement," Agran said.

FivePoint plans to begin land-grading and construction of infrastructure as early as the end of this year, with the first wave of homeowners moving in by 2013.

"I think we are one step away from that moment which we have all been waiting for, which is to put that shovel in the ground," said FivePoint Chief Executive Emile Haddad before the vote.