Exhibit 23.1

Consent of Independent Registered Public Accounting Firm

We consent to the incorporation by reference in the following Registration Statements:

(1) Registration Statement (Form S-8 Nos. 333-134100) pertaining to the 2006 Equity Incentive Plan;

(2) Registration Statement (Form S-1 Nos. 333-196551) pertaining to Amendment No. 1 to Form S-1 Registration Statement; and

(3) Registration Statement (Form S-3 Nos. 333-186786) pertaining to Amendment No. 2 to Form S-1 Registration on Form S-3;

of our report dated December 12, 2014, with respect to the consolidated financial statements of Integrated Electrical Services, Inc. included in this Annual Report (Form 10-K) for the year ended September 30, 2014.

/s/ ERNST & YOUNG LLP

Houston, Texas

December 12, 2014