The twin-tower Sky Ala Moana, a condo-hotel project on Kapiolani Boulevard, won approval from the Honolulu City Council Wednesday.

The Council decision will let the developer build the towers higher than current rules allow. The exemptions were granted as part of the city’s plan to stimulate development around the upcoming rail line.

Passage of Resolution 18-248 gives the go-ahead for the Avalon Group to develop 300 condo­minium-­­hotel units and 474 condo­minium units, of which 84 are required to be within the federal definition of affordable.

The Interim Planned Development-Transit (IDPT) approval allows Avalon to build up to 400 feet. Current regulations for the area call for a height limit of 250 feet.

Testimony on the project ran overwhelmingly in support. Scores of construction workers wrote emails urging Council members not only to approve the project, but to “fast-track” the approval so they can be kept employed.

The Council did just that. The resolution was introduced on Nov. 1 and got its approval from the Zoning and Housing Committee on Nov. 7.

The project, which Avalon estimates carries a $510 million price tag, sits on the site of the current Kenrock low-rise complex. It’s roughly 500 feet from the rail project’s last rail station at Kona and Kona Iki streets.

Avalon anticipates it will take about a year to a year and a half to obtain building permits, company president and CEO Christine Camp said. Under that scenario, units gradually would become available between 2022 and 2025, she said.

A sales office is expected to open in February, she said.

Nathaniel Kinney, executive director of the Hawaii Construction Allliance, said the Sky Ala Moana project will begin work just as the building industry is expected to be in a downturn. “There’s been a 25 percent reduction in building permits in the last year or so,” Kinney said. “We’re looking at a pretty significant slowdown coming up.”

The development also is expected to create up to 810 construction jobs and, upon opening, 540 permanent full-time jobs, 150 of which will be on-site, the company said.

Camp said the project will be the first to include a 30-year buyback provision on its affordable units, meaning they could not be sold for more than affordable rates for three decades. “While we think it’s still a significant market risk, we believe as a local developer we have an obligation to put ourselves out there and put our risks out there,” she said.

Additionally, the market houses “will be priced for people who live here,” Camp said.

While the approval vote was 9-0, several Council members voiced some reservations.

Councilman Ron Menor said he would have preferred the developer provide more units and specifically for those making 80 percent of area median income or less. “I also question whether the 30-year affordability period may negatively impact the marketability of these affordable units,” he said.

Councilman Brandon Elefante raised similar concerns.

But Council Zoning Chairwoman Kymberly Pine said Avalon is providing 21 more affordable units than required and that without the project, none of the affordable units would be built. The concept behind transit oriented development (TOD) zones is not to have all units near a transit line to be affordable, but to include a mix of residential and commercial use priced at different price ranges.

Sky Ala Moana “provides a balance and allows us to build up our housing supply with very little public investment,” she said.

“We’re bringing in money that does not take taxpayer dollars,” Pine said. “The economic impacts from this project that will benefit the taxpayers is huge.”