Officials will hold a grand opening celebration on Wednesday for Bayside Anchor, an energy-efficient, 45-unit affordable apartment building in Portland.

The Portland Housing Authority and Avesta Housing partnered to build the apartments in the city’s East Bayside neighborhood. It includes nine market-rate units and 36 affordable units, which are rented to families earning between $23,000 and $49,000 a year. It is fully occupied.

The ground floor will house a Head Start preschool program, Portland community policing and Portland Housing Authority offices.

The four-story, bright green building has solar panels on the flat rooftop and is the first multifamily building in the city to be certified as a Passive House by the Passive House Institute U.S., according to Avesta Housing. As a energy efficient Passive House, the building does not have a centralized heating system because it is highly insulated, airtight and well-ventilated.

The rooftop of the new apartment complex on East Oxford Street in Portland supports 167 solar electric panels, which supply energy to the first floor of the building. Staff photo by Derek Davis

Portland Housing Authority Executive Director Mark Adelson said in a written statement that Bayside Anchor is the housing authority’s first new development in 45 years and is “our first step in revitalizing our properties in this neighborhood.”

The project is located near housing authority’s Kennedy Park.

The $7.8 million Bayside Anchor project, which was designed by Kaplan Thompson Architects and build by Wright Ryan, both of Portland, was partially funded by loans from Bangor Savings Bank and Enterprise Deutsche Bank, as well federal HOME funds awarded by the city of Portland, Maine Housing HOME funds, and low-income tax housing tax credits from Boston Capital.

The grand opening ceremony will take place at 5 p.m. at 81 East Oxford St. The program will include several speakers, a performance by Portland-based Pihcintu Multicultural Choir and tours of apartments.