<PAGE>

                            STOCK EXCHANGE AGREEMENT

         THIS STOCK EXCHANGE AGREEMENT is made and entered into as of the ____
day of May, 2000, by and between Stonehaven Realty Trust f/k/a Wellington
Properties Trust, a Maryland real estate investment trust ("Seller") and
Wellington Management Corporation, a Wisconsin corporation ("Buyer").

                                R E C I T A L S:
         A. Stonehaven owns all of the issued and outstanding uncertificated
common stock ("Lake Pointe Shares") of Lake Pointe Apartment Homes, Inc., a
Wisconsin corporation ("Lake Pointe"), which owns an apartment living community
in Schofield, Wisconsin ("Lake Pointe Project");

         B. Seller also owns 18 units or member interests ("Highlander Member
Interest") of Highlander Acquisition Company, LLC, a Wisconsin limited liability
company ("Highlander") which owns an apartment living community in Des Moines,
Iowa ("Highlander Project");

         C. Buyer owns 95,000 shares of Class B 9% Convertible Preferred Shares
of Seller ("Class B Preferred Shares");

         D. Buyer desires to acquire Seller's interest in Lake Pointe and the
Lake Pointe Project represented by the Lake Pointe Shares and Seller's interest
in Highlander and the Highlander Project represented by the Highlander Member
Interest in exchange for the transfer of the Class B Preferred Shares owned by
Buyer, all in accordance with the terms of this Agreement.


<PAGE>

                                    AGREEMENT

         1.       PURCHASE OF INTERESTS. At the Closing (as hereinafter defined)
                  Seller shall sell and transfer the Lake Pointe Shares and
                  Highlander Member Interest to Buyer and Buyer hereby agrees to
                  acquire the Lake Pointe Shares and Highlander Member Interest
                  on the terms and conditions set forth in this Agreement.

         2.       EXCHANGE OF STOCK AS CONSIDERATION. In exchange for the Lake
                  Pointe Shares and Highlander Member Interest, Buyer shall
                  transfer the Class B Preferred Shares owned by Buyer to
                  Seller.

         3.       REPRESENTATIONS AND WARRANTIES OF SELLER. Seller represents,
                  warrants and covenants to Buyer that as of the date hereof and
                  as of the Date of Closing:

                  3.1: AUTHORITY. Seller has all requisite power and authority
                  to enter into this Agreement and each agreement, document and
                  instrument to be executed and delivered by Seller pursuant to
                  this Agreement and to carry out the transactions contemplated
                  hereby and thereby. This Agreement and each agreement,
                  document and instrument to be executed and delivered by Seller
                  pursuant to this Agreement constitutes, or when executed and
                  delivered will constitute, the legal, valid and binding
                  obligation of Seller each enforceable in accordance with their
                  respective terms.

                  3.2: LAKE POINTE SHARES. The Lake Pointe Shares are and when
                  delivered to Buyer will be free and clear of any and all
                  pledges, claims, restrictions, charges, liens, security
                  interests, encumbrances or other interests of third parties of
                  any nature whatsoever created by Seller, except for
                  restrictions imposed by federal or state securities laws.

                  3.3: HIGHLANDER MEMBER INTEREST. The Highlander Member
                  Interest when delivered to Buyer will be free and clear of any
                  and all pledges, claims, restrictions, charges, liens,
                  security interests, encumbrances or other interests of third
                  parties of any nature whatsoever created by Seller, except for
                  restrictions imposed by federal or state securities laws.


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<PAGE>

                  3.4: "AS IS" CONDITION. Buyer agrees and acknowledges that
                  Buyer (or an affiliate) is the prior owner of the Lake Pointe
                  Shares and/or Lake Pointe Project and the current manager of
                  the Lake Pointe Project. Buyer is also the organizer and
                  syndicator of Highlander and the current manager of the
                  Highlander Project. As such, Buyer agrees, acknowledges and
                  represents that Buyer is accepting the Lake Pointe Shares,
                  Lake Pointe Project, Highlander Member Interest and Highlander
                  Project on a "as is" "where is" basis without any
                  representations or warranties whatsoever with respect to the
                  value of the Lake Pointe Shares and Highlander Member
                  Interest, the value or financial viability of the Lake Pointe
                  Project or Highlander Project, the physical condition of Lake
                  Pointe Project or Highlander Project and any other matter
                  whatsoever except as specifically set forth in this Agreement.

         4.       REPRESENTATIONS AND WARRANTIES OF BUYER.  Buyer represents,
warrants and covenants to Seller that as of the date hereof and as of the Date
of Closing:

                  4.1: AUTHORITY. Buyer has the full right, power and authority
                  to enter into this Agreement and each agreement, document and
                  instrument to be executed and delivered by Buyer pursuant to
                  this Agreement and to carry out the transactions contemplated
                  hereby and thereby. This Agreement and each agreement,
                  document and instrument to be executed and delivered by Buyer
                  pursuant to this Agreement constitutes, or when executed and
                  delivered will constitute, the legal, valid and binding
                  obligation of Buyer each enforceable in accordance with their
                  respective terms.

                  4.2: CLASS B PREFERRED SHARES. The Class B Preferred Shares
                  are, and when delivered to Seller pursuant to this Agreement
                  will be, free and clear of any and all pledges, claims,
                  restrictions, charges, liens, security interests, encumbrances
                  or other interests of third parties of any nature whatsoever
                  created by Buyer, except for restrictions imposed by federal
                  or state securities laws.

         5.       CLOSING. The Closing of the transaction contemplated hereby
(the "Closing") shall take place at a time mutually acceptable to both Seller
and Buyer which is within five (5) days after receiving written acknowledgment
from First Union Bank as servicer for Credit Suisse First Boston ("Lender")
consenting to the transfer of the Lake Pointe Shares and Lake Pointe Project
from Seller to Buyer as contemplated hereunder. The Closing shall take place at


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<PAGE>

the offices of Wellington Management Corporation or at such other place as may
be mutually agreed upon by the parties.

                  5.1: CLOSING PRORATIONS. At the Closing, the following items
                  shall be prorated or adjusted (as appropriate) as of the close
                  of business on the Date of Closing: (i) city, state, county
                  and school district ad valorem taxes and other taxes
                  (including Lender escrows) and assessments which are actually
                  due and payable in the year of closing (all taxes and
                  assessments due and payable in years subsequent to the Date of
                  Closing shall be the responsibility of Buyer); (ii) all
                  utility or other charges which may become a lien upon the Lake
                  Pointe Project and all service and other related contracts;
                  (iii) casualty insurance premiums (including Lender escrows);
                  (iv) the interest due and owing the Lender (including Lender
                  escrows); (v) all rents, including past due rents; (vi) any
                  other income or expense items properly attributable to the
                  operation of the property and agreed upon by Seller and Buyer.
                  In no event, however, shall prorations include any funds held
                  or set aside for capital improvements, repairs or deferred
                  maintenance which shall remain the property of Seller.

                  5.2: PAYMENTS. At the Closing, Seller shall be entitled to all
                  funds held in any Lake Pointe account and all receivables and
                  other assets of Lake Pointe, except the Lake Pointe Project.
                  The cash balance owing, if any, by either Buyer or Seller
                  pursuant to the prorations as provided in Section 5.1 above,
                  shall be paid directly by Seller to Buyer or Buyer to Seller,
                  as the case may be, by cashier's check, in certified funds, or
                  by wire transfer on the Date of Closing.

                  5.3: SECURITY DEPOSITS. At the Closing, Seller shall transfer
                  its interest in, and Buyer shall assume all obligations under
                  the leases and Seller shall transfer, in cash, all tenant
                  security deposits with respect to the Lake Pointe Project.

         6.       ADDITIONAL ISSUES.
                  6.1: DIVIDEND. Subject to Closing (or upon a breach of this
                  Agreement by Buyer), Buyer waives all claims to any
                  distributions, dividends, or other sums payable, or claimed
                  payable to Buyer in connection with the Class B Preferred
                  Shares.

                  6.2: CONTINUED MANAGEMENT. Buyer shall continue to perform
                  real estate-related management and bookkeeping services with
                  respect to Lake Pointe pursuant to the certain management
                  agreement dated March 3, 1998. Notwithstanding the foregoing,
                  Seller shall have the right to implement such financial
                  controls as Seller deems prudent from and after execution
                  hereof and prior to the Date of Closing and Buyer agrees to
                  cooperate with Seller to


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<PAGE>

                  implement such procedures and controls. In addition thereto,
                  Buyer shall not expend any funds with respect to the Lake
                  Pointe Project nor make any capital or other improvements
                  without the prior written consent or approval of Seller, which
                  consent may be withheld, by Seller in its sole discretion. If
                  the Closing has not occurred on or before August 1, 2000, the
                  Seller shall have the right to terminate the management
                  agreement, without any demonstration of cause, upon no less
                  than thirty (30) days written notice to the Buyer, in
                  accordance with the terms of the management agreement.

                  6.3: TERMINATION OF LISTING AGREEMENT. Upon Closing of the
                  transaction contemplated hereunder, Seller and Buyer and WMC
                  Realty, Inc. agree that that certain Commercial Listing
                  Contract - Exclusive Right to Sell Agreement dated January 15,
                  1998, is hereby terminated in all respects and neither Seller
                  nor WMC Realty, Inc. shall have any rights or obligations
                  thereunder including, without limitation, any rights or
                  obligations with respect to any listing, brokerage or transfer
                  fees. It is agreed that WMC Realty, Inc. shall not receive a
                  brokerage commission upon the closing of the transaction
                  contemplated hereunder and Buyer will indemnify Seller and
                  hold Seller harmless from any claim for commissions by WMC
                  Realty, Inc. and/or any other person or entity claiming a
                  commission by or through Buyer, and its affiliates, including
                  WMC Realty, Inc

                  6.4: RETENTION OF RIGHTS. Notwithstanding anything contained
                  in this Agreement to the contrary, Seller and Buyer agree that
                  Seller retains all rights to conduct a financial accounting or
                  audit and any sums owing by Buyer to either Lake Pointe or
                  Seller as disclosed in any such accounting or audit shall be
                  and remain the property of Seller notwithstanding the transfer
                  or agreement to transfer the Lake Pointe Shares as provided
                  herein. In this regard, Lake Pointe shall be deemed to have
                  assigned such claims, if any, to Seller as of the Date of
                  Closing. Seller reserves and retains all claims of Lake Pointe
                  arising for the period through the Date of Closing and the
                  execution of this Agreement and the subsequent transfer of the
                  Lake Pointe Shares shall not operate as a release of any such
                  claims.

                  6.5:     RELEASES.

                           6.5.1 Release of Seller. Upon Closing, Buyer, for it,
                  its officers, directors, shareholders, principals, affiliated
                  corporations and businesses, successors and assigns, and all
                  other related or affiliated persons or entities, does hereby
                  release and forever discharge Seller and its officers,
                  trustees, shareholders, employees, advisors, attorneys,
                  agents, insurers, affiliated corporations and businesses,
                  successors and assigns, and all other related or affiliated
                  persons or entities, as the case may be, from and against any
                  all claims, demands, causes of actions or rights which Buyer
                  had, now has or could


                                       5
<PAGE>

                  hereinafter have or assert in any manner associated with
                  Seller, its ownership of an equity interest in Seller
                  (including without limitation the Class B Preferred Shares
                  except future rights arising after Closing which Buyer may
                  have as a holder of the Seller's common shares), the business
                  of Seller including the Lake Pointe Project and Highlander
                  Project, and any other matter or thing whatsoever involving
                  Seller and Buyer; notwithstanding the foregoing, the release
                  provisions of this section shall be inapplicable to any breach
                  of this Agreement by Seller, and to any right of
                  indemnification provided by Seller's declaration of trust or
                  bylaws afforded as a result of service as an employee, officer
                  or trustee of Seller. Seller is not released from any
                  obligations to reimburse Buyer for salary and other expenses
                  associated with the employment of Robert F. Rice and sums due
                  and owing for the management of the Lake Pointe Project. The
                  sum of $12,036.82 shall be paid on or before June 2, 2000 and
                  the sum of $58,155.74 shall be paid on or before June 30,
                  2000.

                  6.5.2 Release of Buyer. Upon Closing, Seller, for it, its
                  officers, trustees, shareholders, principals, affiliated
                  corporations and businesses, successors and assigns, and all
                  other related or affiliated persons or entities, does hereby
                  release and forever discharge Buyer and its officers,
                  directors, shareholders, employees, advisors, attorneys,
                  agents, insurers, affiliated corporations and businesses,
                  successors and assigns, and all other related or affiliated
                  persons or entities, as the case may be, from and against any
                  all claims, demands, causes of actions or rights which Seller
                  had, now has or could hereinafter have or assert in any manner
                  associated with Buyer, the business of Buyer including Buyer's
                  management of and interest in the Lake Pointe Project and
                  Highlander Project, and any other matter or thing whatsoever
                  involving Buyer and Seller; notwithstanding the foregoing, the
                  release provisions of this section shall be inapplicable to
                  any breach of this Agreement by Buyer, and to the right to an
                  accounting with respect to the Lake Pointe Project as provided
                  in Section 6.4.

                  6.6: SURVIVAL. The provisions of Sections 6.2, and 6.4 will be
                  operative upon execution hereof and shall not be affected by
                  any termination of this Agreement for failure of the
                  conditions precedent set forth in Sections 7.1 and 7.3 hereof
                  or any termination pursuant to Section 10 hereof.

                  6.7: INDEMNITY. Buyer agrees to indemnify Seller and hold
                  Seller harmless from and against all liabilities and
                  obligations involving Lake Pointe, the Lake Pointe Shares, the
                  Lake Pointe Project, Highlander, the Highlander Member
                  Interest and the Highlander Project, whether such obligations
                  arise prior to, on or after the closing of the transactions
                  contemplated hereunder. As to any claim arising prior to the
                  closing of the transactions contemplated hereunder, Buyer
                  reserves its rights to seek indemnification from Seller
                  pursuant to the management agreement. Buyer specifically
                  agrees to assume and hold Seller harmless from all liabilities
                  to the Lender in connection with that certain


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<PAGE>

                  mortgage loan with the Lake Pointe Project. Buyer shall pay
                  any and all fees, expenses or charges imposed by the Lender or
                  otherwise in connection with the transfer of the Lake Pointe
                  Shares, the Lake Pointe Project, the Highlander Member
                  Interest and Highlander Project to Buyer.

         7.       CONDITION PRECEDENT; DELIVERY OF DOCUMENTS AT CLOSING.

                  7.1: SELLER'S CONDITIONS PRECEDENT. The obligation of Seller
                  to consummate this Agreement and the transactions contemplated
                  hereby is subject to fulfillment prior to or at the Closing of
                  the following conditions precedent:

                           7.1.1    Representations and Warranties. Each of the
                                    representations and warranties of the Buyer
                                    in Section 4 hereof shall be true and
                                    correct on the Date of Closing as though
                                    made on such date and all action necessary
                                    to authorize the execution, delivery and
                                    performance by the Buyer of this Agreement
                                    and each agreement, document and instrument
                                    to be executed and delivered pursuant hereto
                                    and the consummation of the transaction
                                    contemplated hereby and thereby shall have
                                    been duly taken by Buyer.

                           7.1.2    Covenants. Buyer shall have performed all of
                                    its obligations hereunder which by the terms
                                    hereof are to be performed on or before the
                                    Date of Closing.

                  7.2: SELLER'S DELIVERABLES. On the Date of Closing, Seller
                  shall execute, deliver or cause to be executed and delivered
                  to Buyer the following: (i) a bill of sale representing
                  Seller's interest in the Lake Pointe Shares, which are
                  uncertificated shares; (ii) resignations of all officer and
                  director positions with respect to Lake Pointe as Buyer may
                  request in its sole discretion; (iii) any and all documents
                  regarding Lake Pointe and the Lake Pointe Project in the
                  possession of Seller, it being acknowledged that Buyer is in
                  possession of substantially all of such documents; (iv)
                  resolutions of the Board of Trustees of Seller authorizing the
                  execution, delivery and performance by Seller pursuant to this
                  Agreement and the agreements, documents and instruments to be
                  executed and delivered pursuant hereto, including the
                  consummation of the transactions contemplated hereby, and
                  thereby certified by an officer of Seller; (v) a bill of sale
                  representing Seller's interest in the Highlander Member
                  Interest; (vi) any and all documents regarding Highlander and
                  the Highlander Project in the possession of Seller, it being
                  acknowledged that Buyer is in possession of substantially all
                  of such documents; (vii) such other instruments and documents
                  as may be reasonably be required by any of the provisions of
                  this Agreement or reasonably necessary in the opinion of Buyer
                  or Buyer's counsel, to reflect the performance of this
                  Agreement and all other agreements contemplated hereby.


                                       7
<PAGE>

                  7.3: BUYER'S CONDITIONS PRECEDENT. The obligations of Buyer to
                  consummate this Agreement and the transactions contemplated
                  hereby is subject to fulfillment prior to or at the Closing of
                  the following conditions precedent:

                           7.3.1: Representations and Warranties. Each of the
                           representations and warranties of Seller in Section 3
                           hereof shall be true and correct on the Date of
                           Closing as though made on such date.

                           7.3.2:   Covenants.  Seller shall have performed all
                           of its obligations hereunder which by the terms
                           hereof are to be performed on or before the Date of
                           Closing.

                           7.3.3:   Lender Consent. Buyer shall have received
                           the written acknowledgment of Lender consenting to
                           the assignment and transfer of the Lake Pointe Shares
                           and the Lake Pointe Project.

                  7.4: BUYER'S DELIVERABLES. On the Date of Closing, Buyer shall
                  execute, deliver or cause to be executed and delivered to
                  Seller the following: (i) stock certificates for the Class B
                  Preferred Shares, together with all necessary stock powers
                  endorsed by Buyer; (ii) such other instruments and documents
                  as may be required by any other provisions of this Agreement
                  or reasonably necessary, in the opinion of Seller or Seller's
                  counsel, to reflect the performance of this Agreement and all
                  other agreements contemplated hereby.

         8. EXPENSES. Each of the parties to this Agreement shall bear its own
expenses in connection with the negotiation and consummation of the transactions
contemplated by this Agreement.

         9.       GENERAL PROVISIONS.

                  9.1 INCORPORATION OF RECITALS. The Recitals set forth above
                  are incorporated herein and are made a part of this Agreement
                  as if fully set forth herein and shall constitute an
                  expression of the intent of the parties and as an aid in the
                  construction of this Agreement.

                  9.2 ENTIRE AGREEMENT; AMENDMENT. This Agreement constitutes
                  the entire agreement between Seller and Buyer pertaining to
                  the subject matter hereof and supersedes any and all prior or
                  contemporaneous agreements or understandings of the parties
                  relating to the subject matter hereof, whether written or
                  oral. This Agreement may not be modified or amended except
                  pursuant to a written agreement signed by Seller and Buyer.


                                       8
<PAGE>

                  9.3 FURTHER ASSURANCES. The parties agree that after the date
                  of Closing they will from time to time, upon the reasonable
                  request of the other, execute, acknowledge and deliver in
                  proper form any instruments of conveyance or further assurance
                  necessary or reasonably desirable to meet such parties'
                  obligations, liabilities and agreements contemplated
                  hereunder.

                  9.4 COUNTERPARTS. This Agreement may be executed in one or
                  more counterparts, each of which shall be deemed an original,
                  but all of which together shall constitute one and the same
                  original.

                  9.5 NOTICES. All notices, requests, demands or other
                  communications required or permitted by this Agreement shall
                  be in writing, and delivery shall be deemed to be sufficient
                  if delivered personally or by registered or certified mail,
                  return receipt requested, postage-prepaid, addressed as
                  follows:

                       If to the Seller:    Duane H. Lund, CEO
                                            Stonehaven Realty Trust
                                            2550 West University Avenue
                                            Suite 240N
                                            St. Paul, MN 55114

                       With a copy to:      William M. Habicht, Esq.
                                            Messerli & Kramer P.A.
                                            1800 Fifth Street Towers
                                            150 South Fifth Street
                                            Minneapolis, MN  55402

                       If to the Buyer:     Arnold K. Leas
                                            Wellington Management Corporation
                                            18650 W. Corporate Drive, Suite 300
                                            P.O. Box 0919
                                            Brookfield, WI  59008

                       With a copy to:      Gregory Leas, Esq.
                                            Wellington Management Corporation
                                            18650 W. Corporate Drive, Suite 300
                                            P.O. Box 0919
                                            Brookfield, WI  59008

                       or such other addresses as may be specified pursuant
                       to notice given by either party in accordance with
                       the provisions of this subsection.

                  9.6 HEADINGS. The headings used in this Agreement are for
                  convenience only and shall not be deemed to constitute a part
                  hereof, and shall not be


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<PAGE>

                  deemed to limit, characterize or in any way affect the
                  provisions of this Agreement.

                  9.7 SURVIVAL OF TERMS. The agreements, representations and
                  warranties contained in this Agreement shall be deemed to be
                  remade at and survive the Closing.

                  9.8      GOVERNING LAW.  This Agreement shall be governed by
                  and interpreted in accordance with the laws of the State of
                  Minnesota.

                  9.9 BINDING AGREEMENT. Except as otherwise provided herein,
                  this Agreement and the terms, conditions and covenants
                  contained herein and the transactions contemplated hereunder
                  shall be binding upon and inure to the benefit of the parties
                  hereto and their respective successors, representatives and
                  assigns.

         10.      TERMINATION. This Agreement may be terminated and the
transactions contemplated herein may be abandoned after the date of this
Agreement, but not later than the Closing:

                  (a)  by mutual written consent of all parties hereto;

                  (b) by Buyer if any of the conditions provided for in Section
                  7.3 of this Agreement have not been met and have not been
                  waived in writing by Buyer on or before the date of Closing;

                  (c) by Seller if any of the conditions provided for in Section
                  7.1 of this Agreement have not been met and have not been
                  waived in writing by Seller on or before the date of Closing;
                  or

                  (d) by either Seller or Buyer, if the Closing has not occurred
                  by August 1, 2000.

         In the event of termination or abandonment by any parties provided in
         this Section 10, written notice shall be given to the other party(ies)
         and each party shall pay its own expenses incident to preparation for
         consummation of this Agreement and the transactions contemplated
         hereunder and neither party shall have any liability or


                                       10
<PAGE>

         obligation to the other party hereunder except such liabilities or
         obligations as may arise as a result of a breach hereof.

                [Remainder of this page intentionally left blank]


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<PAGE>

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


SELLER:                                 BUYER:


STONEHAVEN REALTY TRUST                 WELLINGTON MANAGEMENT CORPORATION



By: /s/ Duane H. Lund                   By: /s/ Gregory Leas
   -----------------------------------      ---------------------------------
        Its:  Chief Executive Officer           Its: Executive Vice President
             ------------------------                -------------------------


                                        [Agreed as to Section 6.3 only]



                                        WMC REALTY, INC.

                                        By:  /s/ Gregory Leas
                                             -----------------------------
                                                 Its: Executive Vice President
                                                      ------------------------


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