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Exhibit 10.33

CORESITE REALTY CORPORATION

Amended and Restated Non-Employee Director Compensation Policy

        1.    General.    The Non-Employee Director Compensation Policy (the
"Policy"), as set forth herein, was initially adopted by the Board of Directors
(the "Board") of CoreSite Realty Corporation (the "Company") to become effective
as of the completion of the Company's initial public offering of its common
stock and was later amended, with such amendments taking effect on January 1,
2014 (the "Effective Date"). Capitalized but undefined terms used herein shall
have the meanings provided for in the CoreSite Realty Corporation and
CoreSite, L.P. 2010 Equity Incentive Plan, as amended (the "Plan").

        2.    Annual Cash Compensation.    Each member of the Board who is not
employed by the Company, CoreSite, L.P. (the "Partnership") or one of their
affiliates or TC Group, L.L.C. or one of its affiliates (a "Non-Employee
Director") shall be entitled to an annual retainer fee payable in cash with the
amount determined as follows (such amount, the "Annual Retainer"):

          (i)  The annual retainer fee for service on the Board shall be
$75,000;

         (ii)  The annual retainer fee for service on a Board committee (other
than in the role of a committee Chair) shall be an additional $10,000 per
committee;

        (iii)  The annual retainer fee for service as Chair of the Audit
Committee or the Compensation Committee shall be an additional $20,000; and

        (iv)  The annual retainer fee for service as Chair of each other Board
committee shall be an additional $15,000.

        3.    Timing of Payment of Annual Retainers.    Annual Retainers payable
hereunder shall be paid in quarterly installments on or about January 1,
April 1, July 1 and October 1 of each year and shall be subject to the
Non-Employee Director's continued service on the Board on each applicable
payment date.

        4.    Annual Restricted Stock Unit Grants.    Each person who is a
Non-Employee Director immediately following an annual meeting of stockholders
shall be granted, automatically and without necessity of any action by the Board
or any committee thereof, on the date of such annual meeting a number of
Restricted Stock Units having a value equal to $75,000 ("Annual Director RSUs"),
determined by dividing $75,000 by the Fair Market Value of one share of Stock on
the date of such annual meeting. In addition, each Non-Employee Director shall
receive one Dividend Equivalent with respect to each Annual Director RSU that is
granted. The Annual Director RSUs and related Dividend Equivalents shall become
vested on the one-year anniversary of the date of grant, subject to the
Non-Employee Director's continued service to the Company on such date, and shall
be subject to the terms and conditions set forth in the Plan and a Restricted
Stock Unit Agreement in such form as the Board may approve for such awards from
time to time. Members of the Board who are employees of the Company and who
subsequently terminate employment with the Company and remain on the Board, to
the extent that they are otherwise eligible, shall receive, after termination of
employment with the Company, Annual Director RSUs and Dividend Equivalents
pursuant to this Section 4. The Annual Director RSUs and related Dividend
Equivalents shall vest in full upon the occurrence of a Change in Control. The
Company will settle the Annual Director RSUs through the issuance of shares of
Stock at the time of vesting unless a deferral election is made by a
Non-Employee Director pursuant to the following sentence. The Company may allow
a Non-Employee Director to elect to defer settlement of the shares of Stock
issuable with respect to the Annual Director RSUs by submitting a deferral
election form in a form adopted by the Company from time to time, subject to the
requirements of Section 409A of the Internal Revenue Code of 1986, as amended,
and the regulations thereunder ("Section 409A"). All such deferral elections
shall be made in accordance with the rules and procedures for such elections
established by the Company and in accordance with Section 409A.

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        5.    Written Grant Agreement.    The grant of any Award under this
Policy shall be made solely by and subject to the terms set forth in a written
agreement in a form to be approved by the Board and duly executed by an
executive officer of the Company.

        6.    Effect of Other Plan Provisions.    All of the provisions of the
Plan shall apply to the Awards granted automatically pursuant to this Policy,
except to the extent such provisions are inconsistent with this Policy.

        7.    Policy Subject to Amendment, Modification and Termination.    This
Policy may be amended, modified or terminated by the Board in the future at its
sole discretion. Without limiting the generality of the foregoing, the Board
hereby expressly reserves the authority to terminate this Policy during any year
up and until the election of directors at a given annual meeting of
stockholders.

        8.    Effectiveness.    This amended policy shall become effective as of
the Effective Date.

*    *    *    *    *

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Exhibit 10.33

CORESITE REALTY CORPORATION
Amended and Restated Non-Employee Director Compensation Policy