Image courtesy of Gensler

Largely-vacant office buildings near Boston’s North Station would be redeveloped as a 40-story hotel-residential tower under a proposal submitted by Newton-based The RMR Group.

The North Station Gateway project would include a 300-room hotel and 420 residential units in a 560,000-square-foot building at the corner of Causeway and North Washington Streets.

The proposal was submitted just before an Oct. 1 deadline that sets higher required percentages of affordable housing for new developments in Boston.

In a project notification form submitted to the Boston Planning Department, The RMR Group said it’s “exploring options to satisfy the [inclusionary development policy] by creating the required number of affordable units” at a nearby property.

The site includes three parcels occupied by office buildings at 251 Causeway St. and 100 North Washington St. and a small apartment building at 126 North Washington St.

Designed by Gensler, the tower would contain a slender high-rise section containing the residential units that tops out at 450 feet, and a mid-rise section including hotel rooms and retail space whose North End-facing side is partly set back from the street above the third story.

“This project can address the city’s housing needs and contribute to the growing energy and excitement that defines this corner of the city,” RMR Vice President Jesse Abair said in a statement.

Along with Article 80 approval by the Boston Planning & Development Agency board, the project will require variances from the Zoning Board of Appeal for building height, maximum floor area ratio and setback along with the residential use, developers stated in a project notification form.