Factory_OS, a modular-home startup, will be opening a new manufacturing facility later this year in historic Building 680 on Vallejo’s Mare Island.

It has also taken its first order. Google’s parent, Alphabet Inc., is negotiating an order to buy 300 apartment units, with an anticipated value of $25 million–$30 million. The modular homes would address the Silicon Valley housing crisis and serve as temporary housing for employees, according to the Wall Street Journal.

Factory_OS (factoryos.com) is a division of Holliday Development, based in Oakland. It will manufacture multifamily housing in the 250,000-square foot space, which is two to three times as big as most modular-construction facilities. The building has a central corridor that is three football fields long and a central atrium 8 stories tall.

BluHomes (bluhomes.com) had been making its steel-framed, fold-out panelized single-family homes in Building 680 since late 2011. This spring, the company shifted production to plants outside the North Bay, CEO Zephan McMinn told the Business Journal.

Developers will be able to complete their projects faster and at lower cost than conventional construction, and in a controlled environment, Factory_OS said.

The facility is anticipated to open by December 2017 and will employ about 300 people.

“We are excited by the opportunity that this facility and location can offer to our business,” said Rick Holliday, president. “Mare Island offers our business the perfect type of facility and location for this innovative brand of development.”

Factory_OS’s mission is to reduce the cost of housing for individuals and families and includes the involvement of University of California, Berkeley’s Terner Center for Housing Innovation.

Built in 1940 and used to install periscopes in submarines at the former naval shipyard, Building 680 is one of Mare Island’s largest buildings. There are more than 100 businesses on Mare Island representing more than 2,400 full-time jobs and 3.5 million square feet of leased space.