<PAGE>

                                                                Exhibit 10(dd)p1

                                                                 EXECUTION COPY
                                                                 --------------


                               JOINDER AGREEMENT

          Reference is made to the Term Loan Agreement, dated as of July 31,
2000 (as amended, supplemented or otherwise modified from time to time, the
"Loan Agreement"), among GGP Limited Partnership, GGPLP L.L.C., the institutions
from time to time parties thereto as Lenders, Lehman Commercial Paper Inc., as
Syndication Agent, and Bankers Trust Company, as Administrative Agent.  Unless
otherwise defined herein, terms defined in the Loan Agreement and used herein
shall have the meanings given to them in the Loan Agreement.

          Commerzbank AG, New York and Grand Cayman Branches (the "Joining
Lender") (i) represents and warrants that it is legally authorized to enter into
this Joinder Agreement; (ii) confirms that it has received a copy of the Loan
Agreement, together with copies of such other documents and information as it
has deemed appropriate to make its own credit analysis and decision to enter
into this Joinder Agreement; (iii) agrees that it will, independently and
without reliance upon the Co-Agents or any other Lender and based on such
documents and information as it shall deem appropriate at the time, continue to
make its own credit decisions in taking or not taking action under the Loan
Agreement; (iv) appoints and authorizes the Co-Agents to take such action as
agent on its behalf and to exercise such powers under the Loan Agreement as are
delegated to the Co-Agents by the terms thereof, together with such powers as
are reasonably incidental thereto and not otherwise reserved under the Loan
Agreement; (v) agrees that it will perform in accordance with their terms all of
the obligations which by the terms of the Loan Agreement are required to be
performed by it from and after the date hereof as a Lender; (vi) confirms that,
to the best of its knowledge, as of the date hereof, it has not made any
determination which would subject the Borrower to the payment of additional
compensation under Section 13.2 or under Section 13.3 of the Loan Agreement;
(vii) specifies as its Domestic Lending Office (and address for notices) and
Eurodollar Lending Office(s) the offices set forth on Schedule 1 hereto; and
(viii) if the Joining Lender is organized under the laws of a jurisdiction
outside the United States, attaches the forms prescribed by the Internal Revenue
Service of the United States certifying as to the Joining Lender's status for
purposes of determining exemption from United States withholding taxes with
respect to all payments to be made to the Joining Lender under the Loan
Agreement and the Notes or such other documents as are necessary to indicate
that all such payments are subject to such taxes at a rate reduced by an
applicable tax treaty.

          Upon execution and delivery of this Joinder Agreement by the parties
hereto as provided in Section 3.2 of the Loan Agreement, (a) the Joining Lender
hereby shall be a party to the Loan Agreement, shall be a Lender under the Loan
Agreement having the Loan Commitments set forth in Schedule 1 hereto, effective
as of the date of this Joinder Agreement, and shall have the rights and
obligations of a Lender under the Loan Agreement and (b) the Maximum Aggregate
Loan Amount shall be increased to $255,000,000.00.

          THIS JOINDER AGREEMENT SHALL BE GOVERNED BY, AND CONSTRUED AND
INTERPRETED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.
<PAGE>

                                                                Exhibit 10(dd)p2

          This Joinder Agreement may be executed by one or more of the parties
hereto on any number of separate counterparts, and all of said counterparts
taken together shall be deemed to constitute one and the same instrument.
Delivery of an executed signature page hereof by facsimile transmission shall be
effective as delivery of a manually executed counterpart hereof.
<PAGE>

                                                                Exhibit 10(dd)p3

          IN WITNESS WHEREOF, the parties hereto have caused this Joinder
Agreement to be duly executed and delivered by their proper and duly authorized
officers as of this 1st day of August, 2001.

                              COMMERZBANK AG, NEW YORK AND GRAND CAYMAN BRANCHES

                              By:  /s/  Christian Berry
                                   -------------------------------
                                   Name:  Christian Berry
                                  Title:  Assistant Vice President

                              By:  /s/  Douglas P. Traynor
                                   -------------------------------
                                   Name:  Douglas P. Traynor
                                  Title:  Senior Vice President


Accepted and agreed:

GGP LIMITED PARTNERSHIP, a Delaware limited partnership

By:  GENERAL GROWTH PROPERTIES, INC.,
     a Delaware corporation, its sole general partner

     By:   /s/  Bernard Freibaum
           -----------------------------
         Name:  Bernard Freibaum
        Title:  Executive Vice President

GGPLP L.L.C., a Delaware limited liability company

By:  GGP LIMITED PARTNERSHIP,
     a Delaware limited partnership, its managing member

     By:    GENERAL GROWTH PROPERTIES, INC.,
            a Delaware corporation, its sole general partner

     By:   /s/  Bernard Freibaum
           -----------------------------
         Name:  Bernard Freibaum
        Title:  Executive Vice President
<PAGE>

                                                                Exhibit 10(dd)p4

Consented to:

BANKERS TRUST COMPANY, as Administrative Agent

By:    /s/  Steven P. Lapha
       --------------------
     Name:  Steven P. Lapha
    Title   Director

LEHMAN COMMERCIAL PAPER INC., as Syndication Agent

By:    /s/  Francis X. Gilhool
       -----------------------
     Name:  Francis X. Gilhool
    Title   Authorized Signatory