Related Beal will break ground by New Year’s on a 484,000-square-foot housing and hotel complex near North Station that has been billed as a potential model for building middle-class housing in pricey downtown Boston.

After piecing together a financing package including public incentives, the Boston-based developer will set aside 48 units for households earning from 30 percent to 50 percent of the area’s median income (AMI), Related Beal announced today. The remainder would go to those making from 110 percent to 165 percent of the AMI, including 72 units for households making no more than 140 percent. Related Beal has indicated the units will rent for an average of $2.50 per square foot.

Boston officials recently approved a 23-year tax break for the project, Banker & Tradesman reported Monday. The financing package also includes nearly $86 million in bonds from MassDevelopment.

In lieu of property taxes, Related Beal will pay a percentage of revenues from the apartments and a 69-space parking garage to the city. The 121A tax agreement is designed to reduce Related Beal’s costs in the early years of the project before the apartments are fully occupied, Boston Commissioner of Assessing Ron Rakow said. The hotel and 10,000 square feet of retail space will be exempt from property taxes until 2019.

The project will be built on a vacant Massachusetts Department of Transportation-owned parcel left behind by the Big Dig at Causeway and Beverly streets. Related Beal said it has signed a 99-year lease for the property with MassDOT. A copy of the lease was not immediately available from MassDOT or Related Beal. The Boston Globe reported in April the payments would total $12.3 million.

Both the city of Boston and state of Massachusetts are studying which publicly-owned parcels can be offered to developers to build more workforce and affordable housing. Boston Mayor Martin J. Walsh has set a goal of creating 53,000 new residential units by 2030 including 44,000 so-called workforce units for middle-class households.

The financing package also includes the following elements:

• $52 million in tax-exempt bonds and a $33.75-million taxable bond issued by MassDevelopment.
• 4 percent federal and state low-income housing tax credits administered through the Department of Housing and Community Development, that will provide approximately $7.4 million in equity for the project.
• Resources from the Affordable Housing Trust Fund.
• A contribution from a partnership between Boston Properties and Delaware North as part of their affordable housing commitments related to the $1 billion North Station redevelopment project.

“With this project, Related Beal is taking a novel approach to addressing the vital challenge of increasing the supply of workforce housing in Boston,” MassDevelopment President and CEO Marty Jones said in a statement. “MassDevelopment is pleased to support this transit-oriented project, which will provide new opportunities for working families and individuals to continue to live in an increasingly vibrant part of the city.”