Moderna’s former Cambridge headquarters could be turned into affordable housing.

Alexandria Real Estate Equities is looking to unlock an additional 250,000 square feet of commercial development at Technology Square in exchange for converting an existing building at 161 First St. into affordable housing.

The trade Alexandria (NYSE: ARE) is proposing involves 161 First St., a Kendall Square building constructed around 1907 for the Ashton Valve Company.

The Kendall Square building has played host to a number of biotech companies over the years, including Moderna, Sigilon Therapeutics and, more recently, Solid Biosciences. Moderna shifted its headquarters to 200 Technology Square in Cambridge in 2013, and is currently based out of a 462,000-square-foot office and lab building at 325 Binney St.

Alexandria is now offering up the conversion of this existing commercial building into 37,000 square feet of affordable housing. A presentation put together by Alexandria proposed creating 31 units of affordable family housing and adding amenity spaces like laundry, lounge spaces and an outdoor courtyard.

While Alexandria would own the development, it intends to partner with affordable housing developer Beacon Communities which would seek financing through sources like tax credits and public grants.

In exchange for this residential conversion, Alexandria wants to transfer development rights from 161 First St. to allow for an additional 250,000 square feet of commercial development at Technology Square. This gross floor area could be for constructing a new building or an addition to an existing building.

Alexandria has more than 11 million square feet in Greater Boston in total, much of it in and around Kendall Square.

One of those “megacampus ecosystems” is Technology Square. Alexandria acquired the groundlease interest for the 1.2-million-square-foot Kendall Square campus from an MIT affiliate for $600 million in 2006. In 2024, Alexandria agreed to pay $270 million to extend its ground lease through the end of 2088.

Alexandria brought its petition to the Cambridge City Council in August, who referred it to the ordinance committee and planning board. The planning board is slated to have a hearing for the petition during its meeting on Tuesday. The ordinance committee will hear the petition on October 6.

The California-based real estate investment trust did not respond to outreach from the Business Journal.

This story first appeared in the Boston Business Journal.