OPINION OF GOODWIN, PROCTER & HOAR LLP RE:LEGALITY

EXHIBIT 5.1





October 30, 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 (the "Securities Act"), which relates to the sale from time to
time of an indeterminate amount of shares of the Company's preferred stock, par
value $.01 per share ("Preferred Stock"), common stock, par value $.01 per share
("Common Stock"), or any combination of Preferred Stock and Common Stock (the
"Securities"), having a maximum aggregate public offering price of $400,000,000.
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 deem appropriate for the purposes of this opinion, and the
Registration Statement and the exhibits thereto.

Based upon the foregoing, we are of the opinion that (i) when specifically
authorized for issuance by the Company's Board of Directors or an authorized
committee thereof (the "Authorizing Resolution"), (ii) upon receipt by the
Company of the full consideration therefor as provided in the Authorizing
Resolution and (iii) when issued 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.

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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