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                                                                   Exhibit 10.18

                          RETIREMENT BENEFITS AGREEMENT


         THIS RETIREMENT BENEFITS AGREEMENT ("Agreement") is entered into this
18th day of October, 2001 by and between EQUITY RESIDENTIAL PROPERTIES TRUST, a
Maryland real estate investment trust ("ERPT"), and SAMUEL ZELL ("the
Executive").

                                    RECITALS

         WHEREAS, Executive has served as Chairman of Company's Board of
Trustees since 1993; and

         WHEREAS, in recognition of the extraordinary services previously
rendered by Executive and to give Executive incentive to continue rendering such
services, Company wishes to enter into this Agreement; and

         WHEREAS, Executive also wishes to enter into this Agreement.

         NOW, THEREFORE, in consideration of the mutual promises and
considerations contained herein and for other good and valuable consideration,
the payment and adequacy of which is hereby acknowledged, the parties hereto
agree as follows:

         1.       RETIREMENT BENEFITS.

                  (a)      TERMINATION OF EMPLOYMENT. In the event that the
         Executive's employment as Chairman is terminated for any reason
         whatsoever other than the reasons set forth in paragraph 1(b)
         hereunder, the Company shall pay the Executive retirement compensation
         for a ten (10) year period, commencing on the date of termination of
         employment, in an annual amount equal to the Annual Retirement Benefit
         (as defined below) in effect for the calendar year in which the
         termination of employment occurs. Such annual compensation shall be
         payable in equal bi-monthly installments. In the event of the
         Executive's death either prior to Executive's termination of employment
         or during the ten (10) year period in which he is paid annual
         retirement compensation, such Annual Retirement Benefits shall then be
         paid to the estate or any other designee of the Executive.

                  (b)      TERMINATION WITH CAUSE OR RESIGNATION WITHOUT GOOD
         REASON. In the event that the Executive's employment as Chairman
         hereunder is terminated with Cause by ERPT; or (ii) the Executive
         resigns as Chairman without Good Reason on or before age 62, the
         Executive shall not be entitled to receive any retirement compensation
         hereunder.

                  (c)      ANNUAL RETIREMENT BENEFIT. "Annual Retirement
         Benefit" shall mean an amount equal to Five Hundred Thousand Dollars
         ($500,000.00) for calendar year 2001 and 2002, which sum shall be
         increased (but only during Executive's period of employment) as of
         January 1, 2003 and as of the first day of January of each year
         thereafter to an amount equal to the Annual Retirement Benefit in
         effect for the immediately preceding calendar year increased by a
         percentage equal to the

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         percentage increase in the CPI (as defined below) during the
         immediately preceding calendar year over the prior calendar year.

                  (d)      CPI. The term "CPI" shall mean the Revised Consumer
         Price Index for All Urban Consumers published by the Bureau of Labor
         Statistics of the United States Department of Labor, for United States
         City Average, All Items (1982-84 = 100). If the manner in which the CPI
         is calculated shall be substantially revised ERPT and the Executive
         shall select a means to adjust such revised Index, which would produce
         results equivalent, as practicable, to those, which would have been
         obtained if the CPI has not been so revised. If the 1982-84 average
         shall no longer be used as an index of 100, such change shall
         constitute a substantial revision. If the CPI shall become unavailable
         to the public because publication is discontinued, or otherwise, ERPT
         and the Executive shall select a comparable substitute index based upon
         changes in the cost of living or purchasing power of the consumer
         dollar published by any other governmental agency, or, if no such index
         shall then be available, a comparable index published by a major bank
         or other financial institution or by a university or a recognized
         financial publication. In the event that the U.S. Department of Labor,
         Bureau of Labor Statistics, changes the publication frequency of the
         CPI so that a CPI is not available to make an adjustment for the period
         in question, the adjustment shall be based on the percentage increase
         in the CPI for the twelve (12) month period beginning with the closest
         month preceding the period in question for which a CPI is available.

                  (e)      CAUSE. For purposes of this Agreement, a termination
         of employment is for "Cause" if the Executive has been convicted of a
         felony involving fraud or dishonesty or the termination is evidenced by
         a resolution adopted in good faith by at least two-thirds of the Board
         of Trustees that the Executive: (i) intentionally and continually
         failed substantially to perform his reasonably assigned duties with the
         Company (other than a failure resulting from the Executive's incapacity
         due to physical or mental illness or from the Executive's assignment of
         duties that would constitute "Good Reason" as hereinafter defined)
         which failure continued for a period of at least thirty (30) days after
         a written notice of demand for substantial performance has been
         delivered to the Executive specifying the manner in which the Executive
         has failed substantially to perform or (ii) intentionally engaged in
         conduct which is demonstrably and materially injurious to the Company;
         PROVIDED, HOWEVER, that no termination of the Executive's employment
         shall be for Cause as set forth in clause (ii) above until (x) there
         shall have been delivered to the Executive a copy of a written notice
         setting forth that the Executive was guilty of the conduct set forth in
         clause (ii) and specifying the particulars thereof in detail and (y)
         the Executive shall have been provided an opportunity to be heard in
         person by the Board (with the assistance of the Executive's counsel if
         the Executive so desires). Neither an act nor a failure to act, on the
         Executive's part shall be considered "intentional" unless the Executive
         has acted or failed to act with a lack of good faith and with a lack of
         reasonable belief that the Executive's action or failure to act was in
         the best interest of the Company.

                  (f)      GOOD REASON. For purposes of this Agreement, "Good
         Reason" shall mean the occurrence of any of the events or conditions
         described below:

                           (i)      any failure to pay the Executive any
                  compensation or benefits to which he is entitled within thirty
                  (30) days of written notice thereof;

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                           (ii)     the Company's requiring the Executive to be
                  based at any location other than Executive's then principal
                  location for his other business activities;

                           (iii)    the insolvency or the filing (by any party,
                  including the Company) of a petition for bankruptcy of the
                  Company, which petition is not dismissed within sixty (60)
                  days; or

                           (iv)     any material breach by the Company of any
                  provision of this Agreement.

         2.       ARBITRATION. Except as otherwise specifically provided herein,
any controversy or claim arising out of, or relating to this Agreement, or the
breach thereof, shall be settled by arbitration in Chicago, Illinois in
accordance with the rules of the American Arbitration Association, and judgment
upon any award so rendered may be entered in any court having jurisdiction
thereof.

         3.       NOTICES. Any notice or other communication required or
permitted to be transmitted under this Agreement shall be in writing, and
personally delivered or mailed, return receipt requested, postage prepaid,
addressed to the parties hereto at their addresses following their signatures
below, or at such other addresses as may be hereafter designated by a party by
notice delivered in accordance herewith. Any notice delivered personally shall
be effective on the date of delivery and any notice mailed, as aforesaid, shall
be effective on the second day following posting.

         4.       WAIVER OF BREACH. The waiver by one party of a breach of any
provision of this Agreement by the other party shall not operate or be construed
as a waiver of any subsequent breach by the one party.

         5.       ASSIGNMENT. The rights and obligations of ERPT and Executive
under this Agreement shall inure to the benefit of, and shall be binding upon,
ERPT and its successors and assigns and Executive and his heirs and personal
representatives.

         6.       ENTIRE AGREEMENT. This instrument contains the entire
agreement between the parties. It may not be changed orally but only by
agreement in writing signed by the party against whom enforcement of any waiver,
change, modification or discharge is sought.

         7.       GOVERNING LAW; SEVERABILITY. This Agreement shall be construed
and enforced, and all questions concerning compliance by any person with its
terms shall be determined under the laws of the State of Illinois. All
provisions of this Agreement are severable and this Agreement shall be
interpreted and enforced as if all completely invalid or unenforceable
provisions were not contained herein, and partially valid and enforceable
provisions shall be enforced to the extent valid and enforceable.

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         IN WITNESS WHEREOF, the parties have executed this Agreement as of the
day and year first above written.

                                   ERPT:

                                   EQUITY RESIDENTIAL PROPERTIES TRUST, a
                                   Maryland real estate investment trust



                                   By:  /s/                 Douglas Crocker II
                                        ----------------------------------------
                                        Douglas Crocker II, President & CEO

                                   Address:

                                   Two North Riverside Plaza
                                   Chicago, Illinois 60606

                                   EXECUTIVE


                                   /s/                           Samuel Zell
                                   --------------------------------------------
                                   SAMUEL ZELL


                                   Address:

                                   Two North Riverside Plaza
                                   Chicago, Illinois  60606