<DOCUMENT>
<TYPE>EX-8.1
<SEQUENCE>4
<FILENAME>ex8-1.txt
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                                                                     Exhibit 8.1


            [FORM OF OPINION OF WILMER CUTLER PICKERING HALE AND DORR
                            RELATING TO TAX MATTERS]


August 31, 2004


Franklin Street Properties Corp.
401 Edgewater Place
Suite 200
Wakefield, MA  01880-6210

      Re:   Mergers pursuant to Agreement and Plan of Merger between Franklin
            Street Properties Corp., the four corporations listed on Exhibit A
            hereto, and the four corporations listed on Exhibit B hereto.

Ladies and Gentlemen:
This opinion is being delivered to you in connection with filing of the Consent
Solicitation/ Prospectus on Form S-4 (the "Consent Solicitation") with the
Securities and Exchange Commission on ____________, 2004 relating to the
Agreement and Plan of Merger dated as of August 13, 2004 (the "Merger
Agreement"), by and between Franklin Street Properties Corp., a Maryland
corporation ("FSP Corp."), the four Delaware corporations listed on Exhibit A
hereto (each, an "Acquisition Subsidiary" and, collectively, the "Acquisition
Subsidiaries"), and the four other Delaware corporations listed on Exhibit B
hereto (each, a "Target REIT" and, collectively, the "Target REITs"). Pursuant
to the Merger Agreement, each Target REIT will merge with and into an
Acquisition Subsidiary, and the separate existence of each Target REIT shall
thereupon cease (each, a "Merger" and, collectively, the "Mergers"). Except as
otherwise provided, capitalized terms not defined herein have the meanings set
forth in the Merger Agreement and the exhibits thereto or in the letters
delivered to Wilmer Cutler Pickering Hale and Dorr LLP by FSP Corp. and the
Acquisition Subsidiaries and each Target REIT containing certain representations
of FSP Corp., the Acquisition Subsidiaries and each Target REIT relevant to this
opinion (the "Representation Letters"). All section references, unless otherwise
indicated, are to the United States Internal Revenue Code of 1986, as amended
(the "Code").

In our capacity as counsel to FSP Corp. in the Mergers, and for purposes of
rendering this opinion, we have examined and relied upon the Merger Agreement
and the exhibits thereto, the Representation Letters, the Consent Solicitation,
and such other documents as we considered relevant to our analysis. In our
examination of documents, we have assumed the authenticity of original
documents, the accuracy of copies, the genuineness of signatures, and the legal
capacity of signatories.

We have assumed that all parties to the Merger Agreement and to any other
documents examined by us have acted, and will act, in accordance with the terms
of such Merger Agreement and documents and that the Mergers will be consummated
at the Effective Time pursuant to the terms and conditions set forth in the
Merger Agreement without the waiver or modification of any such terms and
conditions. Furthermore, we have assumed that all representations contained in
the Merger Agreement, as well as those representations contained in the
Representation Letters, are, and at the Effective Time will be, true and

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complete in all material respects, and that any representation made in any of
the documents referred to herein "to the best of the knowledge and belief" (or
similar qualification) of any person or party is, and at the Effective Time will
be, correct without such qualification. We have also assumed that as to all
matters for which a person or entity has represented that such person or entity
is not a party to, does not have, or is not aware of, any plan, intention,
understanding, or agreement, there is no such plan, intention, understanding, or
agreement. We have not attempted to verify independently such representations,
but in the course of our representation, nothing has come to our attention that
would cause us to question the accuracy thereof.

The conclusions expressed herein represent our judgment as to the proper
treatment of certain aspects of the Mergers as well as the proper interpretation
of other matters of law covered by our opinion, in each case, under the income
tax laws of the United States based upon the Code, Treasury Regulations, case
law, and rulings and other pronouncements of the Internal Revenue Service (the
"IRS") as in effect on the date of this opinion. No assurances can be given that
such laws will not be amended or otherwise changed after the Effective Time or
that such changes will not affect the conclusions expressed herein.
Nevertheless, we undertake no responsibility to advise you of any developments
after the Effective Time in the application or interpretation of the income tax
laws of the United States.

Our opinion represents our best judgment of how a court would decide if
presented with the issues addressed herein and is not binding upon either the
IRS or any court. Thus, no assurances can be given that a position taken in
reliance on our opinion will not be challenged by the IRS or rejected by a
court.

This opinion addresses only the specific United States federal income tax
consequences set forth below, and does not address any other federal, state,
local, or foreign income, estate, gift, transfer, sales, use, or other tax
consequences that may result from the Mergers or any other transaction
(including any transaction undertaken in connection with the Mergers).

On the basis of, and subject to, the foregoing, and in reliance upon the
representations and assumptions described above, we are of the opinion that:

1.          Each Merger will constitute a reorganization within the meaning of
            Section 368(a).

2.          To the extent that the matters discussed under the heading "Material
            United States Federal Income Tax Considerations" in the Consent
            Solicitation constitute matters of law, they are accurate in all
            material respects.

No opinion is expressed as to any federal income tax consequence of the Mergers
or any other matter except as specifically set forth herein, and this opinion
may not be relied upon except with respect to the consequences specifically
discussed herein.

This opinion is intended solely for the purpose of inclusion as an exhibit to
the Consent Solicitation. It may not be relied upon for any other purpose or by
any other person or entity, and may not be made available to any other person or
entity without our prior written consent. We hereby consent to the filing of
this opinion as an exhibit to the Consent Solicitation and further consent to

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the use of our name in the Consent Solicitation in connection with references to
this opinion and the tax consequences of the Mergers. In giving this consent,
however, we do not hereby admit that we are in the category of persons whose
consent is required under Section 7 of the Securities Act of 1933, as amended.



Very truly yours,


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                                    EXHIBIT A


Montague Acquisition Corp.
Addison Acquisition Corp.
Royal Ridge Acquisition Corp.
Collins Crossing Acquisition Corp.

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                                    EXHIBIT B

FSP Montague Business Center Corp.
FSP Addison Corp.
FSP Royal Ridge Corp.
FSP Collins Crossing Corp.

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