Facebook is taking some serious steps to backup its data, constructing a dedicated underground building right next door to its Prineville, Oregon, facility that will eventually house a ‘deep storage’ device well out of harm’s way.

The social media network said that its ‘Sub-Zero’ project, which was announced earlier this week, will be used as an emergency backup server that’s powered by new technology their engineers are currently building.

Tom Furlong, Facebook’s VP of site operations, said that the building is being optimized to provide specialized support for the new device. The revelation comes just days after Facebook filed for planning permission at the site, which already houses a 300,000 sq. ft. data center.

According to Furlong, Facebook’s engineers still have much work to do on the design for their new storage facility and the equipment it will hold, although he revealed that the new device would consume significantly less power than its regular servers, as they would effectively be ‘switched-off’ while they’re not being used.

“We seriously hope to cut power consumption with Sub-Zero,” stated Furlong. “Right now a rack of Facebook servers burns about 4.5 kilowatts. In the Sub-Zero data center, the goal is to drop this to around 1.5 kWm.”

Apparently, Facebook’s engineers are hoping to design a deep-scale archiving device that provides similar capabilities to tape backup. Facebook doesn’t do tape backups, as the social media company claims that it’s too expensive and clunky – however, it does want to ensure that it always has two backups of its data.

Furlong explained: “We have one that is readily accessible, and then a second one for emergencies that is only accessed in the event of a true restore.”

Once the server is up and running (sometime in the next six to nine months), Facebook has plans for a second deep-storage device at its facility in Forest City, North Carolina.