COPT Publishes 2018 Sustainability Report

Corporate Office Properties Trust ("COPT" or the Company) (NYSE: OFC) has posted its 2018 Sustainability Report in the ?Latest Updates' section of COPT's Investors website: https://investors.copt.com/

Included in the 2018 Sustainability Report are selected highlights from the 2018 Global Real Estate Sustainability Benchmark ("GRESB") survey where COPT earned its 4th consecutive Green Star rating. The GRESB annual survey is the global real estate industry's most rigorous assessment of sustainability performance and its Green Star rating represents high achievement in each of the survey's seven aspects.

COPT's 2018 Sustainability Report outlines the Company's dedication to providing transparency in environmental, social and governance ("ESG") practices that constitute its corporate sustainability platform.

About GRESB

GRESB's mission is to enhance and protect shareholder value by assessing and empowering sustainability practices in the real asset sector. GRESB assesses the sustainability performance of real asset sector portfolios and assets in public, private and direct sectors worldwide. It offers environmental, social, and governance ("ESG") data, scorecards, benchmark reports and portfolio analysis tools.

Its annual dynamic survey collects information regarding the sustainability performance of companies, funds and assets, including information on performance indicators, such as energy, GHG emissions, water and waste. Survey questions are guided by what investors and the industry consider to be material issues in the sustainability performance of real asset investments and are aligned with international reporting frameworks such as GRI and PRI. For more information, please refer to www.GRESB.com.

Company Information

COPT is a REIT that owns, manages, leases, develops and selectively acquires office and data center properties in locations that support the United States Government and its contractors, most of whom are engaged in national security, defense and information technology ("IT") related activities servicing what it believes are growing, durable, priority missions ("Defense/IT Locations"). The Company also owns a portfolio of office properties located in select urban/urban-like submarkets in the Greater Washington, DC/Baltimore region with durable Class-A office fundamentals and characteristics ("Regional Office Properties"). As of March 31, 2019, the Company derived 89% of its core portfolio annualized revenue from Defense/IT Locations and 11% from its Regional Office Properties. As of the same date and including six buildings owned through an unconsolidated joint venture, COPT's core portfolio of 163 office and data center shell properties encompassed 18.2 million square feet and was 93.7% leased; the Company also owned one wholesale data center with a critical load of 19.25 megawatts.

Forward-Looking Information

This press release may contain "forward-looking" statements, as defined in Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934, that are based on the Company's current expectations, estimates and projections about future events and financial trends affecting the Company. Forward-looking statements can be identified by the use of words such as "may," "will," "should," "could," "believe," "anticipate," "expect," "estimate," "plan" or other comparable terminology. Forward-looking statements are inherently subject to risks and uncertainties, many of which the Company cannot predict with accuracy and some of which the Company might not even anticipate. Although the Company believes that the expectations, estimates and projections reflected in such forward-looking statements are based on reasonable assumptions at the time made, the Company can give no assurance that these expectations, estimates and projections will be achieved. Future events and actual results may differ materially from those discussed in the forward-looking statements.

Important factors that may affect these expectations, estimates, and projections include, but are not limited to:

• general economic and business conditions, which will, among other things, affect office property and data center demand and rents, tenant creditworthiness, interest rates, financing availability and property values;
• adverse changes in the real estate markets including, among other things, increased competition with other companies;
• governmental actions and initiatives, including risks associated with the impact of a prolonged government shutdown or budgetary reductions or impasses, such as a reduction in rental revenues, non-renewal of leases, and/or a curtailment of demand for additional space by the Company's strategic customers;
• the Company's ability to borrow on favorable terms;
• risks of real estate acquisition and development activities, including, among other things, risks that development projects may not be completed on schedule, that tenants may not take occupancy or pay rent or that development or operating costs may be greater than anticipated;
• risks of investing through joint venture structures, including risks that the Company's joint venture partners may not fulfill their financial obligations as investors or may take actions that are inconsistent with the Company's objectives;
• changes in the Company's plans for properties or views of market economic conditions or failure to obtain development rights, either of which could result in recognition of significant impairment losses;
• the Company's ability to satisfy and operate effectively under Federal income tax rules relating to real estate investment trusts and partnerships;
• possible adverse changes in tax laws;
• the dilutive effects of issuing additional common shares;
• the Company's ability to achieve projected results;
• security breaches relating to cyber attacks, cyber intrusions or other factors; and
• environmental requirements.

The Company undertakes no obligation to update or supplement any forward-looking statements. For further information, please refer to the Company's filings with the Securities and Exchange Commission, particularly the section entitled "Risk Factors" in Item 1A of the Company's Annual Report on Form 10-K for the year ended December 31, 2018.