OPINION OF GOODWIN PROCTOR & HOAR

EXHIBIT 5.1


[Letterhead of Goodwin, Procter & Hoar LLP]


December 4, 1997



Bay Apartment Communities, Inc.
4340 Stevens Creek Boulevard, Suite 275
San Jose, CA 95129

Re: Legality of Securities to be Registered
under Registration Statement on Form S-3

Ladies and Gentlemen:

This opinion is delivered in our capacity as counsel to Bay Apartment
Communities, Inc., a Maryland corporation (the "Company"), in connection with
the Company's registration statement on Form S-3 (the "Registration Statement")
filed with the Securities and Exchange Commission under the Securities Act of
1933, as amended, which relates to the sale from time to time of an
indeterminate amount of debt securities ("Debt Securities"), shares of preferred
stock, par value $.01 per share ("Preferred Stock"), shares of common stock, par
value $.01 per share ("Common Stock"), or any combination of Debt Securities,
Preferred Stock and Common Stock (collectively, the "Securities"), having a
maximum aggregate public offering price of $600,000,000. The Registration
Statement provides that the Securities may be offered separately or together, in
separate series, in amounts, at prices and on terms to be set forth in one or
more prospectus supplements (each a "Prospectus Supplement") to the prospectus
contained in the Registration Statement.

We have examined the Articles of Incorporation of the Company, as
amended and on file with the Maryland State Department of Assessments and
Taxation, the Bylaws of the Company, as amended, such records of corporate
proceedings of the Company as we have deemed appropriate for the purposes of
this opinion, the Registration Statement and the exhibits thereto.

Based upon the foregoing, we are of the opinion that when the Securities
are specifically authorized for issuance by the Company's Board of Directors or
an authorized committee thereof (the "Authorizing Resolution"), upon receipt by
the Company of the full consideration therefor as provided in the Authorizing
Resolution and upon the issuance of the Securities as described in the
Registration Statement and a Prospectus Supplement that is consistent with the
Authorizing Resolution, the Securities will be legally issued, fully paid and
nonassessable.

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We hereby consent to being named as counsel to the Company in the
Registration Statement, to the references therein to our firm under the caption
"Legal Matters" and to the inclusion of this opinion as an exhibit to the
Registration Statement.

Very truly yours,

/s/ Goodwin, Procter & Hoar LLP

GOODWIN, PROCTER & HOAR LLP

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