The Society of Industrial and Office Realtors (SIOR) is an international professional commercial and industrial real estate association based in Washington, D.C. It offers a professional designation (SIOR) to commercial brokers and other industry professionals. Its membership is composed of around 3,000 individuals and organizations in more than 630 cities in 32 countries. SIOR designees can hold the following specialty designations: industrial, office, sales manager, executive manager, or advisory service. SIOR also includes associate members, who are corporate executives, developers, educators, and other involved in the commercial real estate industry. NAREB. National Association of Real Estate Brokers is NOT the predecessor of NAR. NAREB still exists and is the minority RE brokers trade association founded in 1947 when minorities were NOT allowed. Also, minorities were NOT allowed to join NAR for MANY years. See


The idea of forming an organization for industrial real estate brokers began in 1939. Despite the continued growth of industrial real estate, its specialists had little representation within the National Association of Real Estate Boards (NAREB), the predecessor to today’s National Association of Realtors (NAR). With this in mind and anticipating the increased need for industrial spaces on account of the outbreak of World War II, industrial realtors Frank G. Binswanger and David T. Houston, Sr. made an effort to organize and coordinate industrial realtors across the United States and Canada. They were able to gain sponsorship for the founding of Society of Industrial Realtors (SIR), and in the fall of 1940 at NAREB’s national convention in Philadelphia, and the formation of a national body of industrial realtors was approved. One year and two months later, The United States entered World War II.

SIOR was instrumental in locating existing, and immediately available, plant space that could be utilized for the production of defense, and later, war material. Over 200 brokers from across the United States and Canada surveyed suitable facilities and reported their findings to the War Department (now the Department of Defense).


On average from 2006-2009 SIOR members reported that he or she leased or sold an average of 1.1 million square feet of space for a total dollar volume of $33.4 million in 30 transactions. As a group, SIOR designees closed more than 78,000 transactions.

Requirements for industrial or office brokers:

  • Have a minimum of five years of documented industrial and/or office real estate brokerage experience and is actively engaged as an industrial and/or office real estate broker or salesperson.
  • Maintain a minimum production per year as measured by gross fee income (GFI) and a minimum number of transactions within the standards set by the local chapters. GFI is the fee income directly attributable to the applicant that the applicant’s firm receives before splits. GFI requirements are set by the local chapter and range from $200,000 to $400,000 per year in $50,000 increments.
  • Provide formal recommendations from two Active Individual Members in the applicant’s chapter and outside the applicant’s firm.
  • Must complete either the Core Components of Commercial Brokerage Coursework through the SIOR Center for Career Advancement (CCA) or pass SIOR’s comprehensive membership entrance exam and online ethics course.
  • Uphold high ethical standards of practice and pledge to uphold SIOR's Code of Ethical Principles and Standards of Professional Practice by completing one of the following two options:
  1. SIOR Ethics & Professional Standards course held at a CCA course offering, or
  2. SIOR’s online ethics course.

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