Despite stiff opposition from neighbors, Boston developer Donald J. Chiofaro is sticking with his plan to build two massive towers - one 40 stories and the other 59 stories - on property now occupied by the Harbor Garage along the Rose Fitzgerald Kennedy Greenway.
Residents of the adjacent Harbor Towers condominiums on the Boston waterfront contend the proposed buildings, the bigger of which would rival the Hancock Tower and Prudential Building in height, are too tall and would overshadow the Greenway and surrounding area.
"We are vigorously opposed to Mr. Chiofaro's plan," Harbor Towers trustees said in a statement yesterday. "It is simply too large and imposing for this unique and valuable block."
Chiofaro yesterday filed a formal development proposal with the Boston Redevelopment Authority that promises to transform the garage site from "an eyesore into an icon" and create a new pathway from the Greenway to Boston Harbor.
Chiofaro had previously disclosed the outlines of his proposal, which already had provoked considerable debate due to its unusual design, which is evocative of more angular skyscrapers being built in Asia. A rendering shows Chiofaro's towers connected by a 770-foot terra cotta "skyframe" that creates a rectangular arch that itself is taller than the buildings. The 1.5 million-square-foot development includes a 40-story office tower and a more slender 59-story building that would house 350 hotel rooms and 130 residential units. It also envisions 70,000 square feet of retail space, a 1,400-space underground parking garage, and a glass-encased promenade connecting the Greenway and the harbor.
Chiofaro wants to begin building by the end of 2011. In the meantime, he pledged to address concerns of Harbor Towers residents and the nearby New England Aquarium, which also has questioned the scale of the development and its parking plan.
"We will work very hard to ensure that the Aquarium, and all of our neighbors, benefit from this project," Chiofaro said.
His proposal must clear a number of regulatory hurdles over the next two years: state and federal environmental permits and sign-offs from an array of city agencies. He is also asking city officials to waive zoning rules that limit the height of buildings in the area to 155 feet. The taller builder would be 690 feet, and the shorter one 560 feet.
The BRA is also undertaking a separate review to create new guidelines for construction of buildings along the Greenway.
Chiofaro may also have to deal with federal aviation and Logan Airport officials. A map of height restrictions created by Massport last year appears to limit development around Chiofaro's site to about 700 feet. Chiofaro said he is confident his proposed design complies with regulations.
Casey Ross can be reached at cross@globe.com. 
