Port Authority officials plan to research the idea of rebuilding its aging Midtown Manhattan bus terminal by building on top of the current structure like a layer cake.

The concept, called "build-in-place," would add a new fifth and sixth floor to the top of the existing terminal, located on 42nd Street between Seventh and Eighth Avenues, and then rebuild the floors below, said Steve Platte, chief of major capital projects.

"The build-in-place option is potentially viable from a construction and operational perspective," Platte said at Thursday's board of commissioners meeting. "It is feasible and warrants consideration."

A bus staging and storage facility will be needed to maintain current level of service, Platte said. No details about the cost or timetable for that option were available.

Officials put out a request for proposal to hire consultants to do an environmental review and preliminary engineering, now that a preliminary analysis of build-in-place was conducted by Port Authority staff, a structural firm and engineering consultant. Last month a planning group suggested building a new terminal in the Javits Center basement.

If deemed viable, the build-in-place option could eliminate major issues, such as use of eminent domain, which neighbors around the bus terminal feared would be needed to expand the terminal under other plans. Officials have worked on a replacement since 2013.

That's hampered replacement of the terminal and prompted opposition from New York state and city officials. New York officials have lobbied for building a new terminal in New Jersey next to the Secaucus junction train station, which the commissioners rejected.

Officials said a "robust" public outreach program will be held in both states.

The concept was supported by state Senator Loretta Weinberg, D-Bergen, who has campaigned for the bus terminal's replacement for several years.

"After we answer questions, it may be something we can embrace, if it can accommodate what we need," she said.

Officials approved $3.5 billion in March to design a new bus terminal.

Larry Higgs may be reached at lhiggs@njadvancemedia.com. Follow him on Twitter @commutinglarry. Find NJ.com on Facebook.