1. Organization

        Corporate Office Properties Trust ("COPT") and subsidiaries (collectively, the "Company," "we" or "us") is a fully-integrated and self-managed real estate investment trust ("REIT") that focuses primarily on serving the specialized requirements of strategic customers in the United States Government and defense information technology sectors. We acquire, develop, manage and lease office and data center properties that are typically concentrated in large office parks primarily located adjacent to government demand drivers and/or in office markets that we believe possess growth opportunities. As of December 31, 2011, our investments in real estate included the following:

• •

  238 operating office properties totaling 20.5 million square feet;
  
  

  •

  seven office properties under construction or redevelopment that we estimate will total approximately 903,000 square feet upon completion, including one partially operational property included above;
  
  

  •

  land held or under pre-construction totaling 2,330 acres (including 583 controlled but not owned) that we believe are potentially developable into approximately 20.6 million square feet; and
  
  

  •

  a partially operational, wholesale data center which upon completion and stabilization is expected to have a critical load of 18 megawatts.

        We conduct almost all of our operations through our operating partnership, Corporate Office Properties, L.P. (the "Operating Partnership"), of which we are the managing general partner. The Operating Partnership owns real estate both directly and through subsidiary partnerships and limited liability companies ("LLCs"). A summary of our Operating Partnership's forms of ownership and the percentage of those ownership forms owned by COPT as of December 31, 2011 and 2010 follows:

Three of our trustees also controlled, either directly or through ownership by other entities or family members, an additional 5% of the Operating Partnership's common units of the Operating Partnership ("common units") as of December 31, 2011.

        In addition to owning real estate, the Operating Partnership also owns entities that provide property management and construction and development services primarily for our properties but also for third parties.