POWER OF ATTORNEY

Know all by these presents, that the undersigned hereby constitutes and appoints
any one of Derek S. McCandless, Adam Post or Ned Prusse acting alone, as the
undersigned's true and lawful attorney-in-fact to:

(1) execute for and on behalf of the undersigned, in the undersigned's capacity
as an officer and/or director of CoreSite Realty Corporation, a Maryland
corporation (the "Company"), the Form ID and Forms 3, 4, and 5 in accordance
with Section 16(a) of the Securities Exchange Act of 1934, as amended (the
"Exchange Act") and the rules thereunder;

(2) do and perform any and all acts for and on behalf of the undersigned which
may be necessary or desirable to complete and execute any such Form ID or Form
3, 4, or 5, complete and execute any amendment or amendments thereto, and timely
file such form with the SEC and any stock exchange or similar authority; and

(3) take any other action of any type whatsoever in connection with the
foregoing which, in the opinion of such attorney- in-fact, may be of benefit to,
in the best interest of, or legally required by, the undersigned, it being
understood that the documents executed by such attorney-in-fact on behalf of the
undersigned pursuant to this Power of Attorney shall be in such form and shall
contain such terms and conditions as such attorney-in-fact may approve in such
attorney-in fact's discretion.

The undersigned hereby grants to such attorney-in-fact full power and authority
to do and perform any and every act and thing whatsoever requisite, necessary,
or proper to be done in the exercise of any of the rights and powers herein
granted, as fully to all intents and purposes as the undersigned might or could
do if personally present, with full power of substitution or revocation, hereby
ratifying and confirming all that such attorney-in-fact, or such
attorney-in-fact's substitute or substitutes, shall lawfully do or cause to be
done by virtue of this power of attorney and the rights and powers herein
granted. The undersigned acknowledges that the foregoing attorney-in-fact, in
serving in such capacity at the request of the undersigned, is not assuming, nor
is the Company assuming any of the undersigned's responsibilities to comply with
Section 16 of the Exchange Act.

This Power of Attorney shall remain in full force and effect until the
undersigned is no longer required to file the Form ID or Forms 3, 4, and 5 with
respect to the undersigned's holdings of and transactions in securities issued
by the Company, unless earlier revoked by the undersigned in a signed writing
delivered to the foregoing attorney-in-fact.

IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed as of this 21st day of May, 2019.

					      	/s/ Anthony Hatzenbuehler
						Anthony Hatzenbuehler