This image on may show part of a data-center plan that is part of a lawsuit against Facebook.

An engineering firm that provides data centers has filed a lawsuit against Facebook that accuses the social-media giant of stealing a design and installation method for efficient data centers as well as making those ideas publicly available.

Facebook opened a new data center, the second of two, last year in Lulea, Sweden. The lawsuit implies that Facebook used the company's design and system for that new data center and that Facebook portrayed the innovations to the public as its own.

The heavily redacted complaint, filed in federal district court in San Jose, Calif., on March 23, does not make clear under what  terms, if any, the plaintiff, Bladeroom Group Ltd., made the designs and construction methods available to Facebook.

It also doesn't say if Bladeroom Group was compensated in any way.

Most standard-form contracts in the construction industry provide for architects and engineers to retain ownership of their designs.

For example, the 2008 version of the Engineers Joint Contract Document Committee's E-500 Agreement, which is a contract between an owner and engineer for professional services, provides the engineer with "ownership  and property interest" of all documents and materials prepared by the engineer.

In addition, architectural works are provided copyright protection by federal law adopted by Congress in 1990.

Standard contracts can be rewritten, however, to provide clients with ownership of the designs and documents.

Partnership in U.S. Venture

Based in Cheltenham, England, Bladeroom Group also has a U.S. venture, Chicago-based Bladeroom USA LLC, which is a partnership with a subsidiary of California-based Rosendin Holdings Inc., the largest private U.S. electrical contractor. A website for the venture states that the two companies deliver "large-scale turnkey modular data center projects."

Officials at Facebook could not be reached for comment. Calls made shortly before the Easter holiday weekend to Bladeroom Group's office, to its attorney in San Francisco and to Rosendin Holdings, also were not returned.

The complaint against Facebook is by the Bladeroom Group parent company and another English firm, Bripco, which is described as the legal owner of Bladeroom Group's intellectual property.

The complaint claims that Bladeroom Group had developed a unique methodology and innovative prefabrication process for construction, shipping and installation of modular data centers. Some of the methods are publicly known, while others remain trade secrets, says the company's complaint.

Contact Initiated in 2011

According to the complaint, Bladeroom Group and Bripco initiated contact with Facebook in 2011 but "never imagined that Facebook would end up stealing the BRG Methodology" and partnering with another firm to construct its data centers.

A year ago, Facebook announced that it had awarded the other company a contract to work on a new modular data center at an existing Facebook facility, in Sweden.

According to Datacenter Design, an industry publication, Facebook's data center in Sweden uses modular "flat pack" building techniques.

In January, 2014, Facebook managers spoke at the OpenCompute Project with the goal of giving the public access to the specifications used in Facebook data centers in order to spark collaborative dialogue. From that meeting and a subsequent blog post by Facebook, Bladeroom Group's complaint says, media outlets "picked up the story," including Bladeroom Group's confidential information, and "broadcast it around the world."