
<PAGE>

                                   PROMISSORY NOTE
                                          

$100,000,000                                                     January 5, 1998

     FOR VALUE RECEIVED, Brandywine Realty Trust ("BRT") and Brandywine
Operating Partnership, L.P. (collectively, the "Borrowers"), jointly and
severally, hereby unconditionally promise to pay to NationsBank, N.A.
("Lender"), at its offices located in Charlotte, North Carolina or such other
place as designated by the Lender, the principal sum of ONE HUNDRED MILLION
DOLLARS ($100,000,000) or such lesser principal amount as may be outstanding
from time to time hereunder, in lawful money of the United States of America
and in immediately available funds, together with interest on such principal
amount and such other amounts as may be due and owing hereunder in accordance
with the terms hereof.

     This Note is issued upon, and the undersigned acknowledge and agree to,
the following terms and conditions:

     1.   Definitions.  As used herein the following terms shall have the
meanings herein specified unless the context other requires.

          "Business Day" means any day other than a Saturday, a Sunday, a
     legal holiday or a day on which banking institutions are authorized or
     required by law or other governmental action to close in McLean,
     Virginia, Charlotte, North Carolina or New York, New York; provided that
     in the case of Eurodollar Loans, such day is also a day on which dealings
     between banks are carried on in U.S. dollar deposits in the London
     interbank market.

          "Default" means any event, act or condition which with notice or
     lapse of time, or both, would constitute an Event of Default.

          "Eurodollar Loan" means a Loan bearing interest based at a rate
     determined by reference to the Eurodollar Rate.

          "Eurodollar Rate" means, for the Interest Period for each Eurodollar
     Loan comprising part of the same borrowing (including conversions,
     extensions and renewals), a per annum interest rate determined pursuant
     to the following formula:

               Eurodollar Rate =     London Interbank Offered Rate    
                                  ------------------------------------
                                   1 - Eurodollar Reserve Percentage

          "Eurodollar Reserve Percentage" means, for any day, that percentage
     (expressed as a decimal) which is in effect from time to time under
     Regulation D of the Board of Governors of the Federal Reserve System (or
     any successor), as such regulation may be amended from time to time, or
     any successor regulation, as the maximum reserve requirement (including,
     without limitation, any basic, supplemental, emergency, special, or
     marginal reserves) applicable with respect to Eurodollar liabilities as
     that term is defined in 

<PAGE>

     Regulation D (or against any other category of liabilities that includes
     deposits by reference to which the interest rate of Eurodollar Loans is
     determined), whether or not any Lender has any Eurodollar liabilities
     subject to such reserve requirement at that time. Eurodollar Loans shall
     be deemed to constitute Eurodollar liabilities and as such shall be
     deemed subject to reserve requirements without benefits of credits for
     proration, exceptions or offsets that may be available from time to time
     to a Lender.  The Eurodollar Rate shall be adjusted automatically on and
     as of the effective date of any change in the Eurodollar Reserve
     Percentage.

          "Event of Default" means any of the events or circumstances
     described in Section 7 hereof.

          "Final Maturity Date" means August 5, 1998.

          "Guarantors" has the meaning set forth in the Senior Revolving
     Credit Agreement.

          "Initial Maturity Date" means May 5, 1998.

          "Interest Period" means, as to Eurodollar Loans, a period of one
     months' duration commencing, in each case, on the date of the borrowing
     (including continuations and conversions thereof); provided, however, (a)
     if any Interest Period would end on a day which is not a Business Day,
     such Interest Period shall be extended to the next succeeding Business
     Day (except that where the next succeeding Business Day falls in the next
     succeeding calendar month, then on the next preceding Business Day), (b)
     no Interest Period shall extend beyond the Maturity Date, (c) with
     respect to Eurodollar Loans, where an Interest Period begins on a day for
     which there is no numerically corresponding day in the calendar month in
     which the Interest Period is to end, such Interest Period shall end on
     the last Business Day of such calendar month, and (d) no Interest Period
     shall extend beyond the Initial Maturity Date unless the Maturity Date
     has been extended pursuant to Section 4(c) hereof.

          "Interest Payment Date" means (a) as to Prime Rate Loans, the last
     Business Day of each month and on the Maturity Date, (b) as to Eurodollar
     Loans on the last day of the applicable Interest Period and on the
     Maturity Date.

          "London Interbank Offered Rate" means, for any Eurodollar Loan for
     any Interest Period therefor, the rate per annum (rounded upwards, if
     necessary, to the nearest 1/16 of 1%) appearing on Telerate Page 3750 (or
     any successor page) as the London interbank offered rate for deposits in
     Dollars at approximately 11:00 a.m. (London time) two Business Days prior
     to the first day of such Interest Period for a term comparable to such
     Interest Period; provided, however, if more than one rate is specified on
     Telerate Page 3750, the applicable rate shall be the arithmetic mean of
     all such rates.  If for any reason such rate is not available, the term
     "London Interbank Offered Rate" shall mean, for any Eurodollar Loan for
     any Interest Period therefor, the rate per annum (rounded upwards, if
     necessary, to the nearest 1/16 of 1%) appearing on Reuters Screen LIBO
     Page as the London interbank 

                                          2
<PAGE>

     offered rate for deposits in U.S. dollars at approximately 11:00 a.m.
     (London time) two Business Days prior to the first day of such Interest
     Period for a term comparable to such Interest Period; provided, however,
     if more than one rate is specified on Reuters Screen LIBO Page, the
     applicable rate shall be the arithmetic mean of all such rates.

          "Maturity Date" means the Initial Maturity Date or if the Initial
     Maturity Date is extended in accordance with the terms hereof, the Final
     Maturity Date.

          "Notice of Borrowing" means a request by the Borrowers for a Loan,
     in the form of Exhibit 2(b) attached hereto.

          "Notice of Continuation/Conversion" means a request by the Borrowers
     to continue an existing Eurodollar Loan to a new Interest Period or to
     convert a Eurodollar Loan to a Prime Rate Loan or to convert a Prime Rate
     Loan to a Eurodollar Loan, in the form of Exhibit 2(c) attached hereto.

          "Prime Rate" means the per annum rate of interest established from
     time to time by the Lender at its principal office in Charlotte, North
     Carolina (or such other principal office of the Lender as communicated in
     writing to the Borrowers) as its Prime Rate.  Any change in the interest
     rate resulting from a change in the Prime Rate shall become effective as
     of 12:01 a.m. of the Business Day on which each change in the Prime Rate
     is announced by the Lender.  The Prime Rate is a reference rate used by
     the Lender in determining interest rates on certain loans and is not
     intended to be the lowest rate of interest charged on any extension of
     credit to any debtor. 

          "Prime Rate Loan" means a Loan bearing interest based at a rate
     determined by reference to the Prime Rate.

          "Senior Revolving Credit Agreement" means that certain $300 million
     revolving credit agreement, dated as of the date hereof, among the
     Borrowers, the Subsidiaries of the Borrowers as Guarantors, the Lender,
     as Administrative Agent, and the other lenders party thereto.

     2.   The Loans.  

          (a)  Commitment.  Subject to the terms and conditions set forth
     herein, the Lender agrees to make loans (each a "Loan" and collectively
     the "Loans") to the Borrowers, in U.S. dollars, at any time and from time
     to time, from the date hereof to but not including the Maturity Date;
     provided that the aggregate principal amount of Loans advanced hereunder
     cannot exceed $100,000,000.

          (b)  Method of Borrowing for Loans.  By no later than 11:00 a.m. (i)
     one Business Day prior to the date of the requested borrowing of Loans
     that will be Prime Rate Loans or (ii) three Business Days prior to the
     date of the requested borrowing of Loans that will be Eurodollar Loans,
     the Borrowers shall submit a written Notice of Borrowing in the 

                                          3
<PAGE>

     form of Exhibit 2(b) attached hereto to the Lender setting forth (A) the
     amount requested, (B) whether such Loans shall be Prime Rate Loans or
     Eurodollar Loans, and (C) certification that the Borrowers have complied
     in all respects with Section 6(b) hereof.  The Lender will make the
     requested Loan to the Borrowers on the date set forth in the Notice of
     Borrowing by crediting the account of the Borrowers on the books of the
     Lender.

          (c)  Continuations and Conversions.  The Borrowers shall have the
     option, on any Business Day, to continue existing Eurodollar Loans for a
     subsequent Interest Period, to convert Prime Rate Loans into Eurodollar
     Loans, or to convert Eurodollar Loans into Prime Rate Loans; provided,
     however, that (i) each such continuation or conversion must be requested
     by the Borrowers pursuant to a written Notice of Continuation/Conversion,
     in the form of Exhibit 2(c) attached hereto, in compliance with the terms
     set forth below, (ii) Eurodollar Loans may only be continued or converted
     on the last day of the Interest Period applicable thereto, (iii)
     Eurodollar Loans may not be continued nor may Prime Rate Loans be
     converted into Eurodollar Loans during the existence and continuation of
     a Default or Event of Default and (iv) any request to continue a
     Eurodollar Loan that fails to comply with the terms hereof or any failure
     to request a continuation of a Eurodollar Loan at the end of an Interest
     Period shall result in a conversion of such Eurodollar Loan to a Prime
     Rate Loan on the last day of the applicable Interest Period.  Each
     continuation or conversion must be requested by the Borrowers no later
     than 11:00 a.m. (A) one Business Day prior to the date for a requested
     conversion of a Eurodollar Loan to a Prime Rate Loan or (B) three
     Business Days prior to the date for a requested continuation of a
     Eurodollar Loan or conversion of a Prime Rate Loan to a Eurodollar Loan,
     in each case pursuant to a written Notice of Continuation/Conversion
     submitted to the Lender.

          (d)  Minimum Amounts/Restrictions on Loans.  Each request for a
     borrowing, conversion or continuation shall be subject to the
     requirements that (i) each Eurodollar Loan shall be in a minimum amount
     of $1,000,000 and in integral multiples of $100,000 in excess thereof,
     (ii) each Prime Rate Loan shall be in a minimum amount of $500,000 (and
     integral multiples of $100,000 in excess thereof) or the remaining amount
     available under this Note, (iv) no more than four Loans shall be made
     during any one month and (v) no more than six Eurodollar Loans shall be
     outstanding at any one time.  For the purposes of this Section, all
     Eurodollar Loans with the same Interest Periods beginning on the same
     date shall be considered as one Eurodollar Loan, but Eurodollar Loans
     with different Interest Periods, even if they begin on the same date,
     shall be considered as separate Eurodollar Loans.

          (e)  Appointment of BOP.  BRT hereby appoints BOP to act as its
     agent for all purposes under this Note (including, without limitation,
     with respect to all matters related to the borrowing and repayment of
     Loans) and agrees that (i) BOP may execute such documents on behalf of
     BRT as BOP deems appropriate in its sole discretion and BRT shall be
     obligated by all of the terms of any such document executed on its
     behalf, (ii) any notice or communication delivered by the Lender to BOP
     shall be deemed delivered to BRT and (iii) the Lender may accept, and be
     permitted to rely on, any document, instrument or agreement executed by
     BOP on behalf of a Borrower or BRT.

                                          4
<PAGE>

     3.   Interest.

          (a)  Interest Rate.  From the date hereof until the Initial Maturity
     Date, (i) all Prime Rate Loans shall accrue interest at the Prime Rate
     plus .25% and all Eurodollar Loans shall accrue interest at the
     Eurodollar Rate plus 1.50%.  If the Maturity Date is extended pursuant to
     the terms hereof, then from the day after the Initial Maturity Date until
     the Final Maturity Date, all Prime Rate Loans shall accrue interest at
     the Prime Rate plus .50% and all Eurodollar Loans shall accrue interest
     at the Eurodollar Rate plus 1.75%.

          (b)  Default Rate of Interest.  Upon the occurrence, and during the
     continuance, of an Event of Default, the principal of and, to the extent
     permitted by law, interest on the Loans and any other amounts owing
     hereunder (including without limitation fees and expenses) shall bear
     interest, payable on demand, at a per annum rate equal to four percent
     (4%) plus the rate which would otherwise be applicable (or if no rate is
     applicable, then the rate for Prime Rate Loans plus four percent (4%) per
     annum).

          (c)  Interest Payments.  Interest on Loans shall be due and payable
     in arrears on each Interest Payment Date.  If an Interest Payment Date
     falls on a date which is not a Business Day, such Interest Payment Date
     shall be deemed to be the succeeding Business Day, except that in the
     case of Eurodollar Loans where the succeeding Business Day falls in the
     succeeding calendar month, then on the preceding Business Day.

          (d)  Computation of Interest.  Except for Prime Rate Loans which
     shall be calculated on the basis of a 365 or 366 day year as the case may
     be, all computations of interest hereunder shall be made on the basis of
     the actual number of days elapsed over a year of 360 days.  Interest
     shall accrue from and include the date of borrowing (or continuation or
     conversion) but exclude the date of payment.  It is the intent of the
     Lender and the Borrowers to conform to and contract in strict compliance
     with applicable usury law from time to time in effect.  All agreements
     between the Lender and the Borrowers are hereby limited by the provisions
     of this paragraph which shall override and control all such agreements,
     whether now existing or hereafter arising and whether written or oral.

     4.   Payments.      

          (a)  Place of Payments.  All payments of principal, interest, fees,
     expenses and other amounts to be made by a Borrower under this Note shall
     be received not later than 2:00 p.m. on the date when due, in U.S.
     dollars and in immediately available funds, by the Lender at its offices
     in Charlotte, North Carolina.  Payments received after such time shall be
     deemed to have been received on the next Business Day.  Whenever any
     payment hereunder shall be stated to be due on a day which is not a
     Business Day, the due date thereof shall be extended to the next
     succeeding Business Day (subject to accrual of interest and fees for the
     period of such extension), except that in the case of Eurodollar Loans,
     if the extension would cause the payment to be made in the next following
     calendar month, then such payment shall instead be made on the next
     preceding Business Day.  

                                          5
<PAGE>



          (b)  Voluntary Prepayments.  The Borrowers shall have the right to
     prepay Loans in whole or in part from time to time without premium or
     penalty; provided, however, that Eurodollar Loans may only be prepaid on
     three Business Days' prior written notice to the Lender and any
     prepayment of Eurodollar Loans will be subject to Section 4(d) below. 
     Prepayments shall be applied first to Prime Rate Loans and then to
     Eurodollar Loans in direct order of Interest Period maturities.  Loans
     repaid hereunder may not be reborrowed.

          (c)  Payment in full at Maturity; Extension of Maturity.

               (i)  On the Maturity Date, the entire outstanding principal
          balance of all Loans, together with accrued but unpaid interest and
          all other sums owing with respect thereto, shall be due and payable
          in full, unless accelerated sooner pursuant to Section 8 hereof.

               (ii) If on the Initial Maturity Date (A) no Default or Event of
          Default exists and is continuing and (B) the Borrowers pay to the
          Lender an extension fee equal to one-fourth of one percent (.25%) of
          the then principal amount outstanding under this Note, the Borrowers
          may elect to extend the Maturity Date to the Final Maturity Date;
          provided that if the Borrowers elect to extend the Maturity Date
          pursuant to this Section 4(c)(ii), the Lender may, in its sole
          discretion, elect to require the Borrowers to provide collateral to
          secure its obligations under this Note. The Borrowers shall give
          written notice to the Lender of its desire to effect such election
          at least 20 days, but no more than 45 days, prior to the Initial
          Maturity Date.
          
          (d)  Compensation.  The Borrowers promise to indemnify the Lender
     and to hold the Lender harmless from any loss or expense which the Lender
     may sustain or incur as a consequence of (i) default by the Borrowers in
     making a borrowing of, conversion into or continuation of Eurodollar
     Loans after the Borrowers have given a notice requesting the same in
     accordance with the provisions of this Note, (ii) default by the
     Borrowers in making any prepayment of a Eurodollar Loan after the
     Borrowers have given a notice thereof in accordance with the provisions
     of this Note and (iii) the making of a prepayment of Eurodollar Loans on
     a day which is not the last day of an Interest Period with respect
     thereto.  Such indemnification may include an amount equal to (A) the
     amount of interest which would have accrued on the amount so prepaid, or
     not so borrowed, converted or continued, for the period from the date of
     such prepayment or of such failure to borrow, convert or continue to the
     last day of the applicable Interest Period (or, in the case of a failure
     to borrow, convert or continue, the Interest Period that would have
     commenced on the date of such failure) in each case at the applicable
     rate of interest for such Eurodollar Loans provided for herein minus (B)
     the amount of interest (as reasonably determined by the Lender) which
     would have accrued to the Lender on such amount by placing such amount on
     deposit for a comparable period with leading banks in the interbank
     Eurodollar market.  The agreements in this section shall survive the
     termination of this Note and the payment of the Loans and all other
     amounts payable hereunder.  Notwithstanding the 

                                          6
<PAGE>

     foregoing any prepayment of a Eurodollar Loan made in connection with the
     requirements of Section 3.3(b)(iii) of the Senior Revolving Credit
     Agreement shall not be subject to this Section 4(d).

     5.   Incorporation by Reference.

          (a)  Yield Protection.  Sections 3.9, 3.10, 3.11 and 3.12 of the
     Senior Revolving Credit Agreement are incorporated herein by reference
     (including any defined terms contained therein), to the extent
     applicable, and shall be binding on the Borrowers as if set forth herein.

          (b)  Representations and Warranties.  All of the representations and
     warranties set forth in Section 6 of the Senior Revolving Credit
     Agreement are incorporated herein by reference (including any defined
     terms contained therein) and made and affirmed by the Borrowers to the
     Lender as of the date of this Note and as of such dates as required
     pursuant to Section 6(b) hereof.

          (c)  Covenants.  All of the covenants set forth in Section 7 and
     Section 8 of the Senior Revolving Credit Agreement are incorporated
     herein by reference (including any defined terms contained therein) and
     shall be binding on the Borrowers as if set forth herein.

     6.   Conditions Precedent.  

          (a)  Closing Conditions.  The obligation of the Lender to make the
     initial Loan under this Note is subject to satisfaction of the following
     conditions (in form and substance acceptable to Lender):

               (i)  Executed Documents.  Receipt by the Lender of a duly
          executed copy of this Note.

               (ii) Guaranty Agreement.  Receipt by the Lender of a guaranty
          agreement, in form and substance acceptable to the Lender, executed
          by the Guarantors (the "Guaranty Agreement").

               (iii)     Authority Documents.  Receipt by the Lender of
          documents and certificates from the Borrowers and Guarantors in the
          same form and in the same manner as required by Sections 5.1(b),
          (c), (d) and (e) of the Senior Revolving Credit Agreement.

               (iv) Legal Opinion.  Receipt by the Lender of opinions from
          counsel to the Borrowers and Guarantors, in form and substance
          acceptable to the Lender, addressed to the Lender and dated as of
          the date hereof.

               (v)  Fees and Expenses.  All fees and expenses required to be
          paid by the Borrowers to the Lender under this Note have been paid
          in full.

                                          7
<PAGE>

          (b)  Conditions to Loans.  In addition to the conditions precedent
     stated elsewhere herein, the Lender shall not be obligated to make Loans
     unless:

               (i)  Delivery of Notice.  The Borrowers shall have delivered a
          Notice of Borrowing, duly executed and completed, by the time
          specified in Section 2(b) hereof.

               (ii) Representations and Warranties.  The representations and
          warranties made by the Borrowers as incorporated herein by reference
          are true and correct in all material respects at and as if made as
          of such date except to the extent they expressly relate to an
          earlier date.

               (iii)     No Default.  No Default or Event of Default shall
          exist or be continuing either prior to or after giving effect
          thereto.

               (iv) Availability.  After giving effect to the making of the
          requested Loan, the aggregate principal amount of Loans advanced
          under this Note shall be less than or equal to $100,000,000.
     
The delivery of each Notice of Borrowing shall constitute a representation and
warranty by the Borrowers of the correctness of the matters specified in
subsections (b), (c), and (d) above.

     7.   Events of Default.  An Event of Default shall exist upon the
occurrence of any of the following:

          (a)  Payments.  The Borrowers shall default in the payment (i) when
     due of any principal amount of any Loans or (ii) within three days of
     when due of any interest on the Loans or any fees or other amounts owing
     hereunder.

          (b)  Senior Revolving Credit Agreement.  An Event of Default shall
     exist under the terms of the Senior Revolving Credit Agreement.

          (c)  Guaranty Agreement.  An Event of Default shall exist under the
     terms of the Guaranty Agreement.

     8.   Remedies.  Upon the occurrence of an Event of Default, the Lender
may (a) declare any commitment to advance Loans under this Note to be
terminated, (b) declare all unpaid principal, accrued but unpaid interest and
all other sums owing under this Note to be immediately due and payable in full
without presentation, demand, protest or notice of any kind, all of which are
hereby waived by the Borrowers and/or (c) enforce any and all rights and
interests in accordance with applicable law, including, without limitation,
all rights against the Guarantors and all rights of set-off.

                                          8
<PAGE>

     9.   Miscellaneous.

          (a)  Notices.  Except as otherwise expressly provided herein, all
     notices and other communications shall have been duly given and shall be
     effective (i) when delivered by hand, (ii) when transmitted via telecopy
     (or other facsimile device), (iii) the Business Day following the day on
     which the same has been delivered prepaid to a reputable national
     overnight air courier service, or (iv) the third Business Day following
     the day on which the same is sent by certified or registered mail,
     postage prepaid, in each case to the respective parties at the address or
     telecopy numbers set forth below, or at such other address as such party
     may specify by written notice to the other parties hereto; provided,
     however, that if any notice is delivered on a day other than a Business
     Day then such notice shall not be effective until the next Business Day:

          if to the Borrowers:     [name of Borrower]
                                   c/o Brandywine Operating Partnership, L.P.
                                   Newtown Square Corporate Campus
                                   16 Campus Boulevard, Suite 150          
                                   Newtown Square, Pennsylvania 19073 
                                   Attention:  Gerard H. Sweeney
                                          President and Chief Executive Officer

          if to the Lender:        Cheryl Fitzgerald
                                   NationsBank Real Estate
                                   Structured Debt Group    
                                   8300 Greensboro Drive, Suite 300
                                   McLean, Virginia  22102

                                   Phone:  (703) 761-8170
                                   Fax:      (703) 761-8160

          (b)  Set-Off.  In addition to any rights now or hereafter granted
     under applicable law or otherwise, and not by way of limitation of any
     such rights, upon the occurrence of an Event of Default and the
     commencement of remedies described in Section 8 hereof, the Lender is
     authorized at any time and from time to time, without presentment,
     demand, protest or other notice of any kind (all of which rights being
     hereby expressly waived), to set-off and to appropriate and apply any and
     all deposits (general or special) and any other indebtedness at any time
     held or owing by the Lender (including, without limitation, branches,
     agencies or affiliates of the Lender wherever located) to or for the
     credit or the account of any Borrower against obligations and liabilities
     of such Borrower to the Lender hereunder, irrespective of whether the
     Lender shall have made any demand hereunder and although such
     obligations, liabilities or claims, or any of them, may be contingent or
     unmatured, and any such set-off shall be deemed to have been made
     immediately upon the occurrence of an Event of Default even though such
     charge is made or entered on the books of the Lender subsequent thereto.
     The Borrowers hereby agree that any person purchasing a 

                                          9
<PAGE>

     participation in the Loans hereunder may exercise all rights of set-off
     with respect to its participation interest as fully as if such Person
     were the Lender hereunder.

          (c)  Benefit of Agreement.  This Note shall be binding upon and
     inure to the benefit of and be enforceable by the respective successors
     and assigns of the parties hereto; provided that  the Borrowers may not
     assign and transfer any of their interests without the prior written
     consent of the Lender; and provided further that the Lender may transfer,
     assign or grant participations in its rights and/or obligations hereunder
     as it deems necessary or appropriate.

          (d)  No Waiver; Remedies Cumulative.  No failure or delay on the
     part of the Lender in exercising any right, power or privilege hereunder
     and no course of dealing between the Borrowers and the Lender shall
     operate as a waiver thereof; nor shall any single or partial exercise of
     any right, power or privilege hereunder preclude any other or further
     exercise thereof or the exercise of any other right, power or privilege
     hereunder.  The rights and remedies provided herein are cumulative and
     not exclusive of any rights or remedies which the Lender would otherwise
     have.  No notice to or demand on the Borrowers in any case shall entitle
     the Borrowers to any other or further notice or demand in similar or
     other circumstances or constitute a waiver of the rights of the Lender to
     any other or further action in any circumstances without notice or
     demand.

          (e)  Expenses and Indemnification.  The Borrowers agree to:  (a) pay
     all reasonable out-of-pocket costs and expenses of the Lender in
     connection with (i) the negotiation, preparation, execution and delivery
     and administration of this Note (including, without limitation, the
     reasonable fees and expenses of Moore & Van Allen, special counsel to the
     Lender, (ii) any amendment, waiver or consent relating hereto and thereto
     including, but not limited to, any such amendments, waivers or consents
     resulting from or related to any work-out, renegotiation or restructure
     relating to the performance by the Borrowers under this Note, (iii) the
     enforcement of this Note, including, without limitation, the reasonable
     fees and disbursements of counsel for the Lender, and (iv) any bankruptcy
     or insolvency proceeding of a Borrower or any of its Subsidiaries, and
     (b) indemnify the Lender, its officers, directors, employees,
     representatives and agents from and hold each of them harmless against
     any and all losses, liabilities, claims, damages or expenses incurred by
     any of them as a result of, or arising out of, or in any way related to,
     or by reason of, any investigation, litigation or other proceeding
     (whether or not the Lender is a party thereto) related to the entering
     into and/or performance of this Note or the use of proceeds of any Loans
     (including other extensions of credit) hereunder or the consummation of
     any other transactions contemplated in this Note, including, without
     limitation, the reasonable fees and disbursements of counsel incurred in
     connection with any such investigation, litigation or other proceeding
     (but excluding any such losses, liabilities, claims, damages or expenses
     to the extent incurred by reason of gross negligence or willful
     misconduct on the part of the person to be indemnified).

          (f)  Amendments, Waivers and Consents.  Neither this Note nor any of
     the terms hereof may be amended, changed, waived, discharged or
     terminated unless such 

                                         10
<PAGE>

     amendment, change, waiver, discharge or termination is in writing signed
     by the Borrowers and the Lender.

          (g)  Survival of Indemnification and Representations and Warranties. 
     All indemnities set forth herein and all representations and warranties
     made herein shall survive the execution and delivery of this Note and the
     making of the Loans.

          (h)  Counterparts.  This Note may be executed in any number of
     counterparts, each of which when so executed and delivered shall be an
     original, but all of which shall constitute one and the same instrument.

          (i)  Headings.  The headings of the sections and subsections hereof
     are provided for convenience only and shall not in any way affect the
     meaning or construction of any provision of this Note.
          (j)  Governing Law; Venue.

                    (i)  THIS NOTE AND THE RIGHTS AND OBLIGATIONS OF THE
               PARTIES HEREUNDER SHALL BE GOVERNED BY AND CONSTRUED AND
               INTERPRETED IN ACCORDANCE WITH THE LAWS OF THE STATE OF
               NORTH CAROLINA.  Any legal action or proceeding with
               respect to this Note may be brought in the courts of the
               State of North Carolina in Mecklenburg County, or of the
               United States for the Western District of North Carolina,
               and, by execution and delivery of this Note, each Borrower
               hereby irrevocably accepts for itself and in respect of
               its property, generally and unconditionally, the
               jurisdiction of such courts.  Each Borrower further
               irrevocably consents to the service of process out of any
               of the aforementioned courts in any such action or
               proceeding by the mailing of copies thereof by registered
               or certified mail, postage prepaid, to it at the address
               for notices pursuant to Section 9(a).  Nothing herein
               shall affect the right of the Lender to serve process in
               any other manner permitted by law or to commence legal
               proceedings or to otherwise proceed against a Borrower in
               any other jurisdiction.

                    (ii) Each Borrower hereby irrevocably waives any
               objection which it may now or hereafter have to the laying
               of venue of any of the aforesaid actions or proceedings
               arising out of or in connection with this Note brought in
               the courts referred to in subsection (i) hereof and hereby
               further irrevocably waives and agrees not to plead or
               claim in any such court that any such action or proceeding
               brought in any such court has been brought in an
               inconvenient forum.

                                         11
<PAGE>

          (k)  Waiver of Jury Trial.  EACH OF THE UNDERSIGNED HEREBY
     IRREVOCABLY WAIVES ALL RIGHT TO TRIAL BY JURY IN ANY ACTION, PROCEEDING
     OR COUNTERCLAIM ARISING OUT OF OR RELATING TO THIS NOTE, ANY OF THE OTHER
     DOCUMENTS EXECUTED OR DELIVERED IN CONNECTION HEREWITH OR THE
     TRANSACTIONS CONTEMPLATED HEREBY.

          (l)  Severability.  If any provision of this Note is determined to
     be illegal, invalid or unenforceable, such provision shall be fully
     severable and the remaining provisions shall remain in full force and
     effect and shall be construed without giving effect  to the illegal,
     invalid or unenforceable provisions.

          (m)  Entirety.  This Note, together with the other documents
     referred to herein, represent the entire agreement of the parties hereto
     and thereto, and supersede all prior agreements and understandings, oral
     or written, if any, including any commitment letters or correspondence.

          (n)  Non-Recourse.  Notwithstanding anything herein to the contrary,
     no recourse shall be had against the Brandywine Realty Services
     Partnership or any past, present or future shareholder, officer, director
     or trustee of BRT for any obligation of the Borrowers hereunder, or for
     any claim based thereon or otherwise in respect thereof; provided,
     however, that this subparagraph (n) shall not restrict or limit any claim
     against any such person arising out of or occurring with respect to fraud
     or any intentional misrepresentation or any act or omission that is
     willful or wanton or constitutes gross negligence or willful misconduct.

                                         12
<PAGE>

     This Note is executed as of the date first set forth above.

                         BRANDYWINE REALTY TRUST, a Maryland
                         real estate investment trust

                         By:                                
                            --------------------------------------------------
                              Name:     Gerard H. Sweeney
                              Title:    President and Chief Executive Officer


                         BRANDYWINE OPERATING PARTNERSHIP, L.P.,
                         a Delaware limited partnership

                         By:  Brandywine Realty Trust, a Maryland real
                              estate investment trust, its general partner

                              By:                           
                                 ---------------------------------------------
                                   Name:     Gerard H. Sweeney
                                   Title:    President and Chief Executive 
                                             Officer



ACKNOWLEDGED AND AGREED
AS OF THE DATE FIRST
SET FORTH ABOVE

NATIONSBANK, N.A.


By:                 
   ----------------------
Name:                    
     --------------------
Title:                   
      -------------------

