Image courtesy of The Neighborhood Developers

A $25.35 million tax-exempt bond from MassDevelopment will be used by a nonprofit to acquire and modernize 116 affordable apartments in Chelsea.

The Neighborhood Developers Inc. of Chelsea received the financing for the preservation of income-restricted housing in 21 buildings built between the 1840s and early 20th century.

The acquisitions will preserve income restrictions on the properties that were set to expire in coming years, MassDevelopment announced. The units will be rented to households earning up to 60 percent of area median income, or $72,400 for a family of four.

The projects will include replacement of roofs and mechanical systems, installation of fire suppression devices, structural repairs and upgrades to kitchens and bathrooms.

Chase Bank purchased the bond from MassDevelopment.

The Massachusetts Department of Housing and Community Development approved federal low-income housing tax credits that will generate nearly $18 million in equity for the project.