Press Release

CoreSite Expands in Washington D.C. Market with New DC2 Data Center

Denver, CO—February 23, 2017—CoreSite Realty Corporation (NYSE:COR), a premier provider of secure, reliable, high-performance data center and interconnection solutions across the U.S., today announced that it executed a lease providing for expansion in its Washington D.C. campus, where CoreSite will increase its turn-key data center capacity with the addition of DC2.

The 10-year lease - with renewal rights of three, 5-year extensions at specified rental rates - is for 25,000 square feet of shell capacity. CoreSite expects to commence construction during the second quarter of 2017, and deliver the 25,000 square feet, with a likely critical capacity of approximately 2 MW, during the fourth quarter of 2017, at an estimated cost of approximately $20 million.

“We are excited about expanding our Washington, D.C. campus to meet the new demand generated by our DC1 facility, which is the premier network-centric colocation facility in the Washington, D.C. sub-market. DC1 has more than 60 network, cloud and IT service providers among our customer community,” said Paul Szurek, CoreSite’s Chief Executive Officer. “In line with our campus strategy, we will leverage the proximity to DC1 by procuring high-count dark fiber connecting DC1 and DC2, enabling us to fulfill performance-sensitive demand from networks, content providers, cloud providers, locally-based enterprises, latency-sensitive financial news organizations and government agencies.”

In addition to its Washington, D.C. campus, CoreSite’s current presence in Northern Virginia includes , two stabilized facilities on CoreSite’s Reston, Virginia campus (VA1 and VA2), and one facility in early development stages, part of CoreSite’s recently announced expansion of its Reston campus (VA3). With the expansion at DC2, CoreSite will have more than 1,097,000 square feet of colocation data center space upon full build out, more than 2.5 times its previous square footage. CoreSite’s customer community includes a diverse mix of government, financial services and cloud service providers, as well as domestic and international networks providing a direct connection to U.S and European markets. With the importance of Northern Virginia as a communications and enterprise hub, CoreSite’s Reston and Washington, D.C. campuses provide flexible colocation and hybrid-cloud deployment solutions for customers located in Washington, D.C. and the greater Northern Virginia area.

About CoreSite

CoreSite Realty Corporation (NYSE:COR) delivers secure, reliable, high-performance data center and interconnection solutions to a growing customer community across eight key North American markets. More than 1,200 of the world’s leading enterprises, network operators, cloud providers, and supporting service providers choose CoreSite to connect, protect and optimize their performance-sensitive data, applications and computing workloads. Our scalable, flexible solutions and 430+ dedicated employees consistently deliver unmatched data center options — all of which leads to a best-in-class customer experience and lasting relationships. For more information, visit CoreSite.com.

CoreSite Media Contact

Greer Aviv
VP, Investor Relations and Corporate Communications
+1 303.405.1012
+1 866.777.CORE
greer.aviv@coresite.com

Forward Looking Statements

This press release may contain forward-looking statements within the meaning of the federal securities laws. Forward-looking statements relate to expectations, beliefs, projections, future plans and strategies, anticipated events or trends and similar expressions concerning matters that are not historical facts. In some cases, you can identify forward-looking statements by the use of forward-looking terminology such as "believes," "expects," "may," "will," "should," "seeks," "approximately," "intends," "plans," "pro forma," "estimates" or "anticipates" or the negative of these words and phrases or similar words or phrases that are predictions of or indicate future events or trends and that do not relate solely to historical matters. Forward-looking statements involve known and unknown risks, uncertainties, assumptions and contingencies, many of which are beyond CoreSite's control, that may cause actual results to differ significantly from those expressed in any forward-looking statement. These risks include, without limitation: the geographic concentration of CoreSite's data centers in certain markets and any adverse developments in local economic conditions or the demand for data center space in these markets; fluctuations in interest rates and increased operating costs; difficulties in identifying properties to acquire and completing acquisitions; significant industry competition; CoreSite's failure to obtain necessary outside financing; CoreSite's failure to qualify or maintain its status as a REIT; financial market fluctuations; changes in real estate and zoning laws and increases in real property tax rates; and other factors affecting the real estate industry generally. All forward-looking statements reflect CoreSite's good faith beliefs, assumptions and expectations, but they are not guarantees of future performance. Furthermore, CoreSite disclaims any obligation to publicly update or revise any forward-looking statement to reflect changes in underlying assumptions or factors, of new information, data or methods, future events or other changes. For a further discussion of these and other factors that could cause CoreSite's future results to differ materially from any forward-looking statements, see the section entitled "Risk Factors" in CoreSite's most recent annual report on Form 10-K, and other risks described in documents subsequently filed by CoreSite from time to time with the Securities and Exchange Commission.