SAN JOSE — Developers of a mega office campus in San Jose near the city’s airport have begun to pursue a major expansion of the increasingly successful complex.

The Coleman Highline office complex across from San Jose International Airport would add two new office buildings to the site, under a proposal being crafted by Cupertino-based Hunter Properties, principal developer of the mixed-use campus.

“We are seeing good interest in the project” from potential office tenants, said Curtis Leigh, development director with Hunter Properties.

Hunter Properties is seeking permits for development of two office buildings that together would total roughly 668,000 square feet, according to San Jose city planning documents.

Those two buildings alone would provide enough office space to accommodate 3,300 to 4,500 tech workers. If all eight office buildings planned for the development were constructed, potentially more than 1.5 million square feet of offices would be built, room for 7,500 to 10,000 workers.

“The activity is strong enough where we want to get our permits and be ready to go” to accommodate any companies that might hunger for space in the site, Leigh said. Coleman Highline is located on Coleman Avenue in San Jose between Avaya Stadium and Champions Way.

Roku is the biggest tenant so far in the Coleman Highline development. Roku, a maker of digital media players, has now leased 570,000 square feet of office space in the complex, in deals that were all completed during 2018. Roku also has options to be first in line to lease additional office space, depending on the tech company’s growth requirements.

8×8 signed the initial office lease at Coleman Highline in early 2018, a deal for the rental of 163,000 square feet. However, 8×8, a fast-growing cloud services and communications tech company, appears to have outgrown that space, has yet to occupy the building, and might eventually lease offices in a completely different location.

Coleman Highline will also offer retail and other amenities as part of the development. A new Marriott hotel is slated to sprout on the site, a five-story lodging that will offer at least 170 rooms at a site next to Avaya Stadium.

One of the new office buildings in the 668,000-square-foot development proposal would be nine stories high and the other would rise eight stories, Leigh said.

“By the time we get our entitlements and get a building permit, we could start construction this year,” Leigh said.

On that timetable, one or both of the two newest office buildings could be available sometime in 2021.