Image courtesy Bruner/Cott & Associates

Another long-idled power plant in Boston is being prepped for conversion into life science space.

The former powerhouse at the Charlestown Navy Yard, which has been inactive since 1974, would be replaced by a lab complex under a development plan that got support Thursday from the Boston Planning and Development Agency.

Power House Partners LLC, led by Geoff Lewis and Conroy Development, received tentative designation to replace the contaminated and partially collapsed 1904 building with a new 67,000-square-foot structure, including 44,000 square feet of lab and R&D space and 6,100 square feet of retail space. Conroy Development has redeveloped five buildings in the former Navy yard.

Power House Partners submitted a financial offer of $8 per square foot, equating to $534,720 per year over the term of a 70-year ground lease.

Boston-based architects Bruner/Cott & Associates assembled a diverse design team including partnerships with minority- and women-owned enterprises, Lewis told the BPDA board of directors at its monthly meeting. The subconsultant design team includes 30 percent MWBE’s.

The BPDA last fall requested proposals from developers to replace the blighted property, which is located at Third Avenue and Ninth Street. One other development team, Vision Properties, also submitted a proposal.

The project is significantly smaller in scale than another Boston power plant redevelopment which received approval in January: Hilco Redevelopment Partners’ and Redgate’s 1.7 million-square-foot L Street Station project, which will include 860,000 square feet of office and R&D space at the former Edison plant in South Boston.