EXHIBIT 23.1 CONSENT OF INDEPENDENT AUDITORS We consent to reference to our firm under the caption "Experts" in the Amendment No. 1 to Registration Statement (Form S-4) of Great Lakes Merger Trust and related Proxy Statement of Great Lakes REIT, Inc. and to the incorporation by reference therein of our reports indicated below filed with the Securities and Exchange Commission. Financial Statements Date of Auditors' Report ---------------------- ------------------------ Consolidated financial statements and January 29, 1998, except schedule of Great Lakes REIT, Inc. included for Note 14 as to which in its Annual Report (Form 10-K) for the year the date is March 13, 1998 ended December 31, 1997 Statement of revenue and certain expenses of December 17, 1997 TRI-ATRIA Office Building for the year ended December 31, 1996 included in the Current Report (Form 8-K/A) of Great Lakes REIT, Inc. dated February 6, 1998 Statement of revenue and certain expenses of December 19, 1997 777 Eisenhower Plaza for the year ended December 31, 1996 included in the Current Report (Form 8-K/A) of Great Lakes REIT, Inc. dated February 6, 1998 Ernst & Young LLP Chicago, Illinois June 17, 1998