EXHIBIT 99.1 CERTIFICATION OF PRINCIPAL FINANCIAL OFFICER PURSUANT TO 18 U.S.C. SECTION 1350 In connection with the accompanying Quarterly Report on Form 10-Q of Manufactured Home Communities, Inc. for the quarter ended March 31, 2003, I, John M. Zoeller, Executive Vice President and Chief Financial Officer of Manufactured Home Communities, Inc., hereby certify pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, to the best of my knowledge, that: 1. such Quarterly Report on Form 10-Q of Manufactured Home Communities, Inc. for the quarter ended March 31, 2003 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 such Quarterly Report on Form 10-Q of Manufactured Home Communities, Inc. for the quarter ended March 31, 2003 fairly presents, in all material respects, the financial condition and results of operations of Manufactured Home Communities, Inc. Date: May 10, 2003 By: /s/ John M. Zoeller ------------------- ------------------------------------------- John M. Zoeller Executive Vice President and Chief Financial Officer 27 CERTIFICATION OF CHIEF EXECUTIVE OFFICER PURSUANT TO 18 U.S.C. SECTION 1350 In connection with the accompanying Quarterly Report on Form 10-Q of Manufactured Home Communities, Inc. for the quarter ended March 31, 2003, I, Howard Walker, Chief Executive Officer of Manufactured Home Communities, Inc., hereby certify pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, to the best of my knowledge, that: 1. such Quarterly Report on Form 10-Q of Manufactured Home Communities, Inc. for the quarter ended March 31, 2003 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 such Quarterly Report on Form 10-Q of Manufactured Home Communities, Inc. for the quarter ended March 31, 2003 fairly presents, in all material respects, the financial condition and results of operations of Manufactured Home Communities, Inc. Date: May 10, 2003 By: /s/ Howard Walker ------------------ ------------------------------------------- Howard Walker Chief Executive Officer 28