**EXHIBIT 31.1****CERTIFICATIONS**I, Frank C. Spencer, certify that:1. I have reviewed this quarterly report on Form 10-Q of Cogdell Spencer Inc.; 2. Based on my knowledge, this quarterly report does not contain any untrue statement of amaterial fact or omit to state a material fact necessary to make the statements made, in lightof the circumstances under which such statements were made, not misleading with respect to theperiod covered by this quarterly report; 3. Based on my knowledge, the financial statements, and other financial information included inthis quarterly report, fairly present in all material respects the financial condition,results of operations and cash flows of the registrant as of, and for, the periods presentedin this quarterly report; 4. The registrant’s other certifying officer(s) and I are responsible for establishing andmaintaining disclosure controls and procedures (as defined in Exchange Act Rules 13a-15(e) and15d-15(e)) and internal control over financial reporting (as defined in Exchange Act Rules13a-15(f) and 15d-15(f)) for the registrant and have: (a) Designed such disclosure controls and procedures, or caused such disclosurecontrols and procedures to be designed under our supervision, to ensure that materialinformation relating to the registrant, including its consolidated subsidiaries, ismade known to us by others within those entities, particularly during the period inwhich this quarterly report is being prepared;  (b) Designed such internal control over financial reporting, or caused suchinternal control over financial reporting to be designed under our supervision, toprovide reasonable assurance regarding the reliability of financial reporting and thepreparation of financial statements for external purposes in accordance with generallyaccepted accounting principles;  (c) Evaluated the effectiveness of the registrant’s disclosure controls andprocedures and presented in this quarterly report our conclusions about theeffectiveness of the disclosure controls and procedures, as of the end of the periodcovered by this quarterly report based on such evaluation; and  (d) Disclosed in this quarterly report any change in the registrant’s internalcontrol over financial reporting that occurred during the registrant’s most recentfiscal quarter (the registrant’s fourth fiscal quarter in the case of an annualreport) that has materially affected, or is reasonably likely to materially affect,the registrant’s internal control over financial reporting; and5. The registrant’s other certifying officer and I have disclosed, based on our most recentevaluation of internal control over financial reporting, to the registrant’s auditors and theaudit committee of registrant’s board of directors (or persons performing the equivalentfunctions): (a) All significant deficiencies and material weaknesses in the design oroperation of internal control over financial reporting which are reasonably likely toadversely affect the registrant’s ability to record, process, summarize and reportfinancial information; and  (b) Any fraud, whether or not material, that involves management or otheremployees who have a significant role in the registrant’s internal control overfinancial reporting.        Date: May 10, 2007 By:   /s/ Frank C. Spencer   Name:  Frank C. Spencer   Title:  Chief Executive Officer  
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