Exhibit 99.1

FOR IMMEDIATE RELEASE

CommonWealth REIT Announces 2013 Second Quarter Results

Newton, MA (August 7, 2013): CommonWealth REIT (NYSE: CWH) today announced financial results for the quarter and six months ended June 30, 2013.

Results for the Quarter Ended June 30, 2013:

Normalized funds from operations, or Normalized FFO, available for CommonWealth REIT common shareholders for the quarter ended June 30, 2013 was $74.5 million, or $0.63 per share basic and diluted, compared to Normalized FFO available for CommonWealth REIT common shareholders for the quarter ended June 30, 2012 of $69.8 million, or $0.83 per share basic and diluted.

Net income available for CommonWealth REIT common shareholders was $7.7 million for the quarter ended June 30, 2013, compared to $2.2 million for the same quarter last year.  Net income available for CommonWealth REIT common shareholders per share, basic and diluted (EPS), for the quarters ended June 30, 2013 and 2012 was $0.07 and $0.03, respectively.  Net income for the quarter ended June 30, 2013 includes a loss of $4.6 million, or $0.04 per share, from asset impairment, partially offset by a gain of $2.1 million, or $0.02 per share, from the sale of properties.

The weighted average number of basic and diluted common shares outstanding for the quarters ended June 30, 2013 and 2012, was 118,309,343 and 83,726,908, respectively.

A reconciliation of net income attributable to CommonWealth REIT, determined according to U.S. generally accepted accounting principles, or GAAP, to funds from operations, or FFO, available for CommonWealth REIT common shareholders and Normalized FFO available for CommonWealth REIT common shareholders for the quarters ended June 30, 2013 and 2012 appears later in this press release.

A Maryland Real Estate Investment Trust with transferable shares of beneficial interest listed on the New York Stock Exchange.  No shareholder, Trustee or officer is personally liable for any act or obligation of the Trust.

Results for the Six Months Ended June 30, 2013:

Normalized FFO available for CommonWealth REIT common shareholders for the six months ended June 30, 2013 was $148.3 million, or $1.40 per share basic and diluted, compared to Normalized FFO available for CommonWealth REIT common shareholders for the six months ended June 30, 2012 of $145.8 million, or $1.74 per share basic and diluted.

Net income available for CommonWealth REIT common shareholders was $22.3 million for the six months ended June 30, 2013, compared to $12.1 million for the same period last year.  Net income available for CommonWealth REIT common shareholders per share, basic and diluted (EPS), for the six months ended June 30, 2013 and 2012 was $0.21 and $0.14, respectively.  Net income for the six months ended June 30, 2013 includes a gain of $66.3 million, or $0.62 per share, from the sale of an equity investment, partially offset by losses of $60.0 million, or $0.56 per share, from the early extinguishment of debt.

The weighted average number of basic and diluted common shares outstanding for the six months ended June 30, 2013 and 2012, was 106,298,433 and 83,724,322, respectively.

A reconciliation of net income attributable to CommonWealth REIT determined according to GAAP to FFO available for CommonWealth REIT common shareholders and Normalized FFO available for CommonWealth REIT common shareholders for the six months ended June 30, 2013 and 2012 appears later in this press release.

Operating Results:

As of June 30, 2013, 89.2% of CWH’s consolidated total square feet from continuing operations was leased, compared to 90.0% as of March 31, 2013 and 89.8% as of June 30, 2012.

CWH entered into consolidated lease renewals for 959,000 square feet and consolidated new leases for 628,000 square feet during the quarter ended June 30, 2013, which had weighted average cash rental rates that were 0.2% below prior rents for the same leasable space.  The consolidated weighted average lease term based on square feet for leases entered into during the second quarter of 2013 was 6.9 years.  Consolidated commitments for tenant improvements, leasing commission costs and concessions for leases entered into during the quarter ended June 30, 2013 totaled approximately $49.7 million, or $4.54 per square foot per year of the lease term.

Consolidated same property occupancy for properties owned continuously since April 1, 2012 decreased 1.3 percentage points from 89.7% to 88.4%, largely because of the 607,500 square feet lease vacancy beginning on April 1, 2013 at One Franklin Plaza, Philadelphia, PA.  Consolidated same property cash net operating income increased by 2.3% during the second quarter of 2013, largely because of rent increases in Oahu, HI.

Recent Acquisitions and Sales Activities:

Since January 1, 2013, CWH has not acquired or entered into any agreements to purchase properties, excluding transactions by Select Income REIT, or SIR.  As of June 30, 2013, SIR was CWH’s consolidated subsidiary and owned substantially all of CWH’s consolidated commercial and industrial properties located in Oahu, HI, as well as 43 suburban

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office and industrial properties located throughout the mainland United States.  As discussed below, on July 2, 2013, SIR completed an underwritten public offering of its common shares, at which time CWH ceased to own a majority of SIR’s common shares.  Accordingly, beginning with the filing of CWH’s Quarterly Report on Form 10-Q for the period ended September 30, 2013, CWH will deconsolidate its investment in SIR and account for its investment in SIR under the equity method.

During the six months ended June 30, 2013, CWH sold 24 properties with a combined 2.3 million square feet and two land parcels for an aggregate sale price of $42.6 million, excluding closing costs.  As of June 30, 2013, 70 properties with a combined 4.4 million square feet located throughout the United States were listed for sale with third party brokers and classified as held for sale.  As of today, 49 of these properties with a combined 2.3 million square feet are under agreement to sell for an aggregate sale price of $67.5 million, excluding closing costs.  CWH expects to sell the 49 properties currently under agreement and the remaining 21 properties listed for sale during 2013; however, no assurance can be given that any of the properties will be sold in that time period or at all.

Recent Financing Activities:

On July 2, 2013, SIR completed a public offering of 10,500,000 of its common shares for net proceeds (after deducting underwriters’ discounts and estimated expenses) of $283.7 million.  After this offering, CWH continued to own 22,000,000, or approximately 44.2%, of SIR’s common shares and SIR ceased to be CWH’s consolidated subsidiary.

Presentation:

Unless otherwise noted, the amounts reported above are on a consolidated basis and, as such, include the results of SIR, which was CWH’s consolidated subsidiary until July 2, 2013.  For further information about SIR and its subsidiaries, please see SIR’s periodic reports and other filings with the Securities and Exchange Commission, or the SEC, which are available at the SEC’s website at www.sec.gov.  References in this press release to SIR’s filings with the SEC are included to identify the source of SIR information only, and the information in SIR’s filings with the SEC is not incorporated by reference into this press release.

Conference Call:

Later today, at 1:00 p.m. Eastern Time, Adam Portnoy, President and Managing Trustee, and John Popeo, Chief Financial Officer, will host a conference call to discuss the financial results for the quarter ended June 30, 2013.

The conference call telephone number is (800) 230-1085.  Participants calling from outside the United States and Canada should dial (612) 288-0329.  No pass code is necessary to access either call.  Participants should dial in about 15 minutes prior to the scheduled start of the call.  A replay of the conference call will be available through 11:59 p.m. Eastern Time on Wednesday, August 14, 2013.  To hear the replay, dial (320) 365-3844.  The replay pass code is 296728.

A live audio webcast of the conference call will also be available in a listen only mode on CWH’s website, which is located at www.cwhreit.com.  Participants wanting to access the webcast should visit CWH’s website about five minutes

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before the call.  The archived webcast will be available for replay on CWH’s website for about one week after the call.

The transcription, recording and retransmission in any way of CWH’s second quarter conference call are strictly prohibited without the prior written consent of CWH.

Supplemental Data:

A copy of CWH’s Second Quarter 2013 Supplemental Operating and Financial Data is available for download at CWH’s website, www.cwhreit.com.  CWH’s website is not incorporated as part of this press release.

CommonWealth REIT is a real estate investment trust which primarily owns office properties located throughout the United States.  CWH is headquartered in Newton, MA.

Please see the pages attached hereto for a more detailed statement of CWH’s operating results and financial condition and for an explanation of CWH’s calculation of FFO and Normalized FFO and a reconciliation of net income attributable to CommonWealth REIT to those amounts.

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WARNING CONCERNING FORWARD LOOKING STATEMENTS

THIS PRESS RELEASE CONTAINS STATEMENTS THAT CONSTITUTE FORWARD LOOKING STATEMENTS WITHIN THE MEANING OF THE PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995 AND OTHER SECURITIES LAWS.  ALSO, WHENEVER CWH USES WORDS SUCH AS “BELIEVE”, “EXPECT”, “ANTICIPATE”, “INTEND”, “PLAN”, “ESTIMATE” OR SIMILAR EXPRESSIONS, CWH IS MAKING FORWARD LOOKING STATEMENTS.  THESE FORWARD LOOKING STATEMENTS ARE BASED UPON CWH’S PRESENT INTENT, BELIEFS OR EXPECTATIONS, BUT FORWARD LOOKING STATEMENTS ARE NOT GUARANTEED TO OCCUR AND MAY NOT OCCUR.  ACTUAL RESULTS MAY DIFFER MATERIALLY FROM THOSE CONTAINED IN OR IMPLIED BY THESE FORWARD LOOKING STATEMENTS AS A RESULT OF VARIOUS FACTORS.  FOR EXAMPLE:

·                  ON JUNE 21, 2013, CORVEX MANAGEMENT LP, OR CORVEX, DELIVERED A LETTER TO CWH ASSERTING THAT CWH’S BOARD OF TRUSTEES HAS BEEN REMOVED AND NO LONGER HAS AUTHORITY TO ACT FOR CWH BY REASON OF A PURPORTED SHAREHOLDERS’ CONSENT SOLICITATION BY CORVEX, RELATED FUND MANAGEMENT, LLC AND CERTAIN OF THEIR AFFILIATES, OR TOGETHER WITH CORVEX, CORVEX/RELATED. CWH BELIEVES THIS PURPORTED SHAREHOLDERS’ CONSENT HAS NO LEGAL EFFECT. THE LEGAL EFFECTIVENESS OF THE CORVEX/RELATED ACTIVITIES TO REMOVE CWH’S ENTIRE BOARD OF TRUSTEES IS CURRENTLY THE SUBJECT OF LEGAL PROCEEDINGS BEFORE AN ARBITRATION PANEL UNDER THE AUSPICES OF THE AMERICAN ARBITRATION ASSOCIATION. THE REMOVAL OF CWH’S ENTIRE BOARD OF TRUSTEES, AS PROPOSED BY CORVEX/RELATED, COULD CAUSE SEVERAL ADVERSE CONSEQUENCES TO CWH’S CONTINUED OPERATIONS, INCLUDING: (I) DEFAULT OF CWH’S REVOLVING CREDIT FACILITY AND TERM LOAN AGREEMENTS PERMITTING CWH’S LENDERS TO ACCELERATE REPAYMENTS, (II) ACTIVATION OF DILUTIVE EQUITY CONVERSION RIGHTS UNDER CWH’S SERIES D CUMULATIVE CONVERTIBLE PREFERRED SHARES, (III) POSSIBLE DEFAULTS OF CERTAIN MORTGAGE DEBT OBLIGATIONS, (IV) POSSIBLE CROSS DEFAULTS OF CWH’S OTHER DEBT OBLIGATIONS INCLUDING CWH’S APPROXIMATELY $1.5 BILLION OF UNSECURED NOTES, AND (V) CWH’S FAILURE TO MEET NYSE AND SEC REQUIREMENTS TO ALLOW CWH’S SECURITIES TO CONTINUE TO BE PUBLICLY TRADED.  THE RESULTS OF LITIGATION AND ARBITRATION ARE DIFFICULT TO PREDICT AND CWH IS UNABLE TO PROVIDE ANY ASSURANCES REGARDING SUCH RESULTS;

·                  THIS PRESS RELEASE STATES THAT CWH HAS ENTERED INTO AGREEMENTS TO SELL PROPERTIES.  THESE TRANSACTIONS ARE SUBJECT TO VARIOUS TERMS AND CONDITIONS TYPICAL OF COMMERCIAL REAL ESTATE TRANSACTIONS.  THE TERMS AND CONDITIONS MAY NOT BE MET.  AS A RESULT, THESE TRANSACTIONS MAY NOT OCCUR OR MAY BE DELAYED OR THE TERMS MAY CHANGE; AND

·                  THIS PRESS RELEASE STATES THAT CWH EXPECTS TO SELL IN 2013 THE REMAINING PROPERTIES NOT ALREADY SOLD THAT ARE CLASSIFIED AS HELD FOR SALE AS OF JUNE 30, 2013.  HOWEVER, CWH MAY BE UNABLE TO SELL SOME OR ALL OF THESE PROPERTIES IN 2013 OR EVER.

THE INFORMATION CONTAINED IN CWH’S FILINGS WITH THE SEC, INCLUDING UNDER THE CAPTION “RISK FACTORS” IN CWH’S PERIODIC REPORTS, OR INCORPORATED THEREIN, IDENTIFIES OTHER IMPORTANT FACTORS THAT COULD CAUSE DIFFERENCES FROM CWH’S FORWARD LOOKING STATEMENTS.  CWH’S FILINGS WITH THE SEC ARE AVAILABLE ON THE SEC’S WEBSITE AT WWW.SEC.GOV.

YOU SHOULD NOT PLACE UNDUE RELIANCE UPON FORWARD LOOKING STATEMENTS.

EXCEPT AS REQUIRED BY LAW, CWH DOES NOT INTEND TO UPDATE OR CHANGE ANY FORWARD LOOKING STATEMENTS AS A RESULT OF NEW INFORMATION, FUTURE EVENTS OR OTHERWISE.

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CommonWealth REIT

Condensed Consolidated Statements of Operations, Funds from Operations and

Normalized Funds from Operations

(amounts in thousands)

(unaudited)

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CommonWealth REIT

Condensed Consolidated Statements of Operations, Funds from Operations and

Normalized Funds from Operations (continued)

(amounts in thousands, except per share data)

(unaudited)

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CommonWealth REIT

Condensed Consolidated Statements of Operations, Funds from Operations and

Normalized Funds from Operations (continued)

(amounts in thousands)

(unaudited)

(1)   CWH calculates FFO and Normalized FFO as shown above.  FFO is calculated on the basis defined by The National Association of Real Estate Investment Trusts, or NAREIT, which is net income, calculated in accordance with GAAP, plus real estate depreciation and amortization, loss on real estate asset impairment, net income attributable to noncontrolling interest and FFO from equity investees, excluding any gain or loss on sale of properties, equity in earnings from investees and FFO attributable to noncontrolling interest.  CWH’s calculation of Normalized FFO differs from NAREIT’s definition of FFO because CWH excludes acquisition related costs, gain from sale of equity investment, loss on early extinguishment of debt, the difference between average minimum rent and interest earned from CWH’s direct financing lease and the difference between FFO and Normalized FFO from equity investees and noncontrolling interest.  CWH considers FFO and Normalized FFO to be appropriate measures of operating performance for a REIT, along with net income, net income attributable to CommonWealth REIT, net income available for CommonWealth REIT common shareholders, operating income and cash flow from operating activities. CWH believes that FFO and Normalized FFO provide useful information to investors because by excluding the effects of certain historical amounts, such as depreciation expense, FFO and Normalized FFO may facilitate a comparison of CWH’s operating performance between periods and between CWH and other REITs.  FFO and Normalized FFO are among the factors considered by CWH’s Board of Trustees when determining the amount of distributions to CWH’s shareholders.  Other factors include, but are not limited to, requirements to maintain CWH’s status as a REIT, limitations in CWH’s revolving credit facility and term loan agreement and public debt covenants, the availability of debt and equity capital to CWH, CWH’s cash available for distribution, CWH’s expectation of its future capital requirements and operating performance, and CWH’s expected needs and availability of cash to pay its obligations.  FFO and Normalized FFO do not represent cash generated by operating activities in accordance with GAAP and should not be considered as alternatives to net income, net income attributable to CommonWealth REIT, net income available for CommonWealth REIT common shareholders, operating income or cash flow from operating activities, determined in accordance with GAAP, or as indicators of CWH’s financial performance or liquidity, nor are these measures necessarily indicative of sufficient cash flow to fund all of CWH’s needs.  CWH believes that FFO and Normalized FFO may facilitate an understanding of its consolidated historical operating results.  These measures should be considered in conjunction with net income, net income attributable to CommonWealth REIT, net income available for CommonWealth REIT common shareholders, operating income and cash flow from operating activities as presented in CWH’s Condensed Consolidated Statements of Operations, Condensed Consolidated Statements of Comprehensive (Loss) Income and Condensed Consolidated Statements of Cash Flows.  Other REITs and real estate companies may calculate FFO and Normalized FFO differently than CWH does.

(2)   Assuming no fundamental change has occurred, as of June 30, 2013, CWH’s 15,180 outstanding series D cumulative convertible preferred shares were convertible into 7,298 common shares and the effect of a conversion of CWH’s series D cumulative convertible preferred shares on income from continuing operations attributable to CommonWealth REIT common shareholders per share is anti-dilutive to income, FFO and Normalized FFO for all periods presented.  Set forth below is the calculation of diluted net income available for common shareholders, diluted FFO available for common shareholders, diluted Normalized FFO available for common shareholders and diluted weighted average common shares outstanding (assuming no fundamental change has occurred).  If the arbitration panel determines that the Corvex/Related consent solicitation is legally effective and CWH’s entire Board of Trustees has been removed, such removal would constitute a fundamental change under the 6.5% series D cumulative convertible preferred shares giving holders of such shares the option to convert these shares into common shares at a ratio based on 98% of the average closing market price for a period before such removal is effective unless CWH repurchases these shares for their par value plus accrued and unpaid distributions.

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CommonWealth REIT

Condensed Consolidated Balance Sheets

(amounts in thousands, except share data)

(unaudited)

(END)

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