Brookline-based developer Longwood Group marked a milestone in construction of a 195-unit apartment complex on South Huntington Avenue in Jamaica Plain with a topping-off ceremony Monday.

Members of the building trades including Local 7 Ironworkers signed the final roof beam during the ceremony attended by Boston Redevelopment Authority officials and local elected representatives.

Named Serenity, the 246,186 square-foot steel-framed building with a brick, glass and metal panel exterior ranges from 5 to 13 stories.

The low-rise segment will house 32 “premium” apartments, primarily two- and three-bedroom units, overlooking Olmsted Park with a separate private elevator. The mid-rise section will consist primarily of studios and one- and two-bedroom units.

Designed by Prellwitz Chilinski Assoc. of Cambridge, the building will seek LEED Silver certification with water-efficient kitchens and bathrooms and an energy recovery system. Residents will have access to Zipcars, electric car charging stations and bicycle storage.

Amenities will include 24-hour concierge and security services, lounge, billiard room, meeting and collaborative areas by RD Jones interior design, a courtyard by Copley Wolff Design Group, roof deck pool with lounge, barbecue deck and green roof, Wi-Fi access in all common areas and direct-access garage parking. Units feature oversized windows and Nest thermostat systems.

Lending was provided by US Bank and Parse Capital.

Completion is projected in spring 2017. Boston-based Suffolk Construction is the general contractor.