MENLO PARK, Calif. — John Tenanes, Facebook’s vice president for real estate, is showing off the company’s plans for expansion. It will have offices for thousands of programmers to extend Facebook’s fearsome reach. But that is not what Tenanes is excited about.

He leans over a scale model of the 59-acre site, which is named Willow Village. “There will be housing there,” he points. “There will be a retail street along here, with a grocery store and a drugstore. That round building in the corner? Maybe a cultural center.”

In just a few years, Facebook built a virtual community that linked more than 2 billion people, an achievement with few precedents. The social network is building a real community, the kind you can walk around.

Facebook, Tenanes says, has a dual mission: “We want to balance our growth with the community’s needs.”

Willow Village will be wedged between the Menlo Park neighborhood of Belle Haven and the city of East Palo Alto, heavily Hispanic communities that are among Silicon Valley’s poorest. Facebook is planning 1,500 apartments, and it has agreed with Menlo Park to offer 225 of them at below-market rates. The most likely tenants of the full-price units are Facebook employees, who receive a five-figure bonus if they live near the office.

The community will have 8 acres of parks, plazas and bike-pedestrian paths open to the public. Facebook wants to revitalize the railway running alongside the property and will finish next year a pedestrian bridge over the expressway. The bridge will provide access to the trail that rings San Francisco Bay, a boon for birders and bikers.

Tenanes contemplates the audacity of building a city. “It’s a good thing, right?” he says.

Depends how it goes. Facebook is testing the proposition: Do people love tech companies so much they will live inside of them? When the project was announced last summer, critics dubbed it Facebookville or, in tribute to company co-founder Mark Zuckerberg, Zucktown.

The company has not warmed to these names. “I owe my soul to the company store,” Tennessee Ernie Ford sang. But Facebook’s ambitions are confronting a more urgent problem: an escalating crisis over the company’s power to sway elections, its casual approach to data privacy and its susceptibility to Russian manipulation. If Facebook’s image is permanently sullied by the furor over Cambridge Analytica, the data firm hired by President Donald Trump’s 2016 election campaign, Zucktown will falter before it is finished.

The social media colossus is not the only Big Tech company in the complicated position of dressing up its expansion as a gift to its neighbors.

A few miles down the 101 highway, another new civic-corporate partnership is underway in the city of Mountain View. Google is promising to place the public “in the very heart of Google’s vibrant community.”

The search company plans a 600,000-square-foot office building with a roof that melts up into soft peaks, kind of like a meringue. It will have stores, cafes, gardens and a space for theatrical performances, as well as a place for consumers to test-drive Google technology.

Google will build 5,000 homes on its property under an agreement brokered with Mountain View in December. Call it Alphabet City as a nod to Alphabet, Google’s corporate parent. The company said it was figuring out its future as a landlord and declined further comment.

Zucktown and Alphabet City, as well as similar projects being contemplated across Silicon Valley, could at a minimum have consequences for the startup culture that transformed fruit orchards into the world’s greatest tech hub. Silicon Valley was built by engineers jumping from company to company. That drove the innovation that sped the rise of some firms and hastened the demise of others.

As workers begin to live at the office, they will inevitably be more beholden to bosses who also collect the rent. It is much harder to find a place to live in Silicon Valley than a new job. Turnover may slump, and so might the turnover in ideas.

On a wall in the Facebook division charged with the company’s growth there is a poster with a classic tech admonition: “Go Big or Go Home.” Facebook is in essence tweaking that to “Go Big at Home.” About 12,000 of its 25,000 employees work in Menlo Park. In a decade, it will have space for 35,000 — slightly more than the city’s current population.