MOUNTAIN VIEW — Microsoft unveiled plans Tuesday for a major reconstruction and upgrade of its main Silicon Valley campus in Mountain View, which will modernize the site and add water-saving, green features.

Related Articles Sunnyvale retail real estate deals: $81 million

Tiffany plans sleek new San Jose store at Valley Fair

Amazon to locate new fulfillment center in East Bay

New downtown San Jose transit village comes into view

Affordable housing eyed at San Jose site where hotel was planned near Google village The unveiling comes as Bay Area tech companies are considering new construction, upgrading existing campuses — or in Apple’s case, settling into newly built facilities — to create modern, attractive workplaces for employees.

“This project represents a significant investment in our more than 2,000 employees in the San Francisco Bay Area and our commitment to creating the best employee experience in the industry,” Kevin Scott, Microsoft’s chief technology officer, wrote in a blog post Tuesday.

Redmond, Washington-based Microsoft estimated it will take two years to build the revamped, 643,000-square-foot Mountain View complex, which should be ready to occupy in December 2019.

“This is a case of another tech company saying that, despite the housing prices and the traffic problems in the Bay Area, that they think Silicon Valley is one of the places where they want to expand,” said Stephen Levy, an economist and director of the Palo Alto-based Center for Continuing Study of the California Economy.

The company said the campus will be “our smartest, greenest office yet,” with highly efficient water use for the site — located in California’s often drought-prone climate.

“One hundred percent of the buildings’ non‑drinking water will come from rainfall or on-site recycled water,” said Pauline Souza, a partner with WRNS Studio Architecture & Planning. “This will be a first in Silicon Valley.”

The company seeks to achieve what is known as a “Net-Zero Water Usage” campus.

“Beyond drinking fountains and sinks, not a drop of water for more than 2,000 employees, 15 acres of landscape, and 643,000 square feet of built space will come from municipal sources,” Microsoft stated in its blog post.

Microsoft has emptied out the campus with the construction underway.

“Employees will be working from our other office locations in Sunnyvale during construction,” said Austin Stewart, a Microsoft spokesman.

Tech companies in Silicon Valley are dangling enticements in front of recruits or current employees, such as offices with attractive surroundings, near mass transit, restaurants, shopping and outdoor activities.

Besides the expansions by Microsoft, tech companies such as Google, Apple, LinkedIn and Facebook have worked to create offices near their existing campuses or develop big outposts in Silicon Valley to expand their teams.

“Almost all the big tech companies are saying they want to expand in Silicon Valley,” Levy said. “It’s a strong affirmation of Silicon Valley’s economic strength.”

Get tech news in your inbox weekday mornings. Sign up for the free Good Morning Silicon Valley newsletter.

In downtown San Jose, Google wants to develop a transit-oriented village consisting of 6 million to 8 million square feet of offices that could accommodate 15,000 to 20,000 of its workers. The village would rise near Diridon Station, which already has transit stops for light rail, Caltrain, Amtrak, the ACE Train and buses, and is planned as a stop for BART and a bullet train.

“Tech companies believe that it’s possible for this area to solve the housing crisis and the transportation problems,” Levy said. “I think it can. But we’ll see.”