SAN JOSE — One of downtown San Jose’s most prominent buildings, a 1980s-era structure, would be replaced by a modern office tower through a new venture formed by a busy downtown developer.

The Davidson Building, perched on West Julian Street near the ramps for State Route 87, and at one of the gateways into downtown San Jose, would be replaced by an office tower totaling up to 700,000 square feet, under a new plan being fashioned by the project’s developers.

Gary Dillabough, involved in a widening array of projects in downtown San Jose, has struck a deal to team up with building owner Charles Davidson and local developers Tony Arreola and Mark Lazzarini to construct an office tower at 255 W. Julian St. that would range in size from 600,000 to 700,000 square feet.

“This project would be at a very important, prominent location,” Dillabough said. “It’s at a gateway for downtown San Jose.”

The six-story, 56,000-square-foot building, which legendary Silicon Valley developer and builder Charles Davidson, a pioneer of downtown construction, built in 1984, could be bolstered by the new building height limits recently approved by the San Jose City Council.

“We can get some additional height for the building,” Dillabough said, referring to the relaxed city rules for how tall buildings can be when they sprout near the airport’s flight paths.

Individual floors in the new building would be 50,000 to 60,000 square feet in size, Dillabough estimated. Those kinds of wide-open spaces are coveted by tech firms.

Dillabough said he’s looking forward to his development venture with Davidson, Lazzarini and Arreola.

“We are excited that Chuck Davidson shares our vision and enthusiasm for how San Jose can take the next step for its downtown,” Dillabough said.

More than a year ago, Dal Properties, whose principal executives are Arreola and Lazzarini, had proposed development of two residential towers on the site that would have added 653 housing units.

“Gary’s investments and vision for downtown San Jose are something that we are excited about because San Jose is our home and we are committed to building communities we can all be proud of,” Arreola said. “We look forward to creating a class A user experience at our proposed office tower.”

The residential towers plan is being shelved in favor of an iconic office tower at a location that would beckon people both into the core part of the downtown as well as the area of the Google transit village proposed for the western edges of San Jose’s urban heart.

“Given our Valley’s job growth and market demands for office space in downtown San Jose, changing our proposal from housing to office makes a lot of sense because it complements all of the housing being built next to our property,” Arreola said. “Having an airport and a major transit center within a few minutes from our property, makes our office tower extremely appealing.”

The project site is about two freeway exits from San Jose International Airport and a few blocks from the Diridon train station, already a hub for links to Caltrain, ACE Train, Amtrak, Capitol Corridor and light rail lines, and a future site for a BART station.

“This project presents a great opportunity to replace a legacy office building that still stands from the days of the first urban pioneers in downtown San Jose,” San Jose Mayor Sam Liccardo said in an interview. “We hope that the renewed interest in office construction will spur more housing development.”

The office tower development, while still being designed, could well become an icon to visibly help downtown San Jose stand out.

“Our partner Charles W. Davidson is a development pioneer in the Valley and he has done so much for this community over the years,” Arreola said. “We propose to carry out his legacy by designing an iconic office building that can be a symbol of what Silicon Valley is all about.”