Exhibit 99.1

                CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350,
                       AS ADOPTED PURSUANT TO SECTION 906
                        OF THE SARBANES-OXLEY ACT OF 2002

       In connection with the Annual Report on Form 10-K of Heritage Property
Investment Trust, Inc. (the "Company") for the period ending December 31,
2002, as filed with the Securities and Exchange Commission on the date hereof
(the "Report"), I, Thomas C. Prendergast, President and Chief Executive
Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as
adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that, to
the best of my knowledge: (1) the Report fully complies with the requirements
of Section 13(a) or 15(d) of the Securities Exchange Act of 1934, and (2) the
information contained in the Report fairly presents, in all material
respects, the financial condition and the results of operations of the
Company.

                                        Heritage Property Investment Trust, Inc.



                                        By: /s/ Thomas C. Prendergast
                                           ------------------------------------
                                           Thomas C. Prendergast
                                           President and Chief Executive Officer