SAN JOSE — A buyer has emerged for the Rail Yard Place project that’s been proposed for downtown San Jose, a mixed-use complex of offices and homes that will serve as a key gateway to the city’s urban core.

The new proposal envisions a project on Ryland Street that would consist of 150,000 square feet of office space and 500 residential units, according to documents on file with the San Jose Planning Department.

“We have a buyer for the property,” said Dennis Randall, a Bay Area developer who is a partner with John Pringle, another local developer, at Insight Realty, which now owns the choice 10-acre site. “We have Rail Yard Place under contract.”

The buyer is an affiliate of SummerHill Apartment Communities, which itself is a unit of Summerhill Housing Group, a major residential developer, according to information in city planning documents.

Summerhill would develop both the apartment portion of the project as well as the office building, according to Randall.

The terms of the purchase contract, including the timing and conditions to complete the transaction, weren’t disclosed.

The complex, perched next to State Route 87 and a short distance from the Guadalupe River and Diridon train station, is considered a crucial project that would greet visitors to downtown San Jose.

“This is a premier location in San Jose,” Randall said. “It’s going to be the gateway to that part of downtown San Jose. When you come into the downtown from Highway 87, this will be the first project you see.”

The office building is expected to be five stories high and will include four levels of underground parking, the city planning documents show.

The apartment component of Rail Yard Place is expected to consist of multi-family rental units.

Development activity in this part of downtown San Jose has intensified since early 2017 when it became apparent that Google intended to develop a transit village near the Diridon train station consisting of offices, homes, restaurants, and retail where 25,000 would work, including 15,000 to 20,000 of the search giant’s employees.

Google’s development proposal has sparked interest on a widening number of fronts in the western edges of downtown San Jose.

“The downtown core is getting extended,” said Bob Staedler, principal executive with San Jose-based Silicon Valley Synergy, a planning consultancy. “That allows for sites that have been long vacant to be thought of as places for mixed-use development.”

Santa Clara County government agencies have leased three large office buildings nearby. Plus, Boston Properties, TMG Partners, and Valley Oak Partners have begun to clear the site for a million-square-foot tech campus of modern office buildings.

And next to all of this activity, Google has collected numerous properties for its anticipated transit village complex.

“An urban village with more jobs and housing makes sense at this location,” Staedler said. “There is a need for both offices and residential uses here.”

Downtown San Jose has begun to turn the corner and is poised to experience wide-ranging development projects and tech company expansions in the city center. But it isn’t quite there yet, Randall said.

“We are on the verge of greatness in downtown San Jose,” Randall said. “But it’s not great yet.”