accommodations extended and to be extended by the Guaranteed Creditors to the Company and EMCOR UK.

          NOW, THEREFORE, in consideration of the benefits accruing to the Guarantors, and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the parties hereto agree as follows:

          1. Each Additional Guarantor acknowledges and agrees that it shall become a “Guarantor” party to the Guaranty effective upon the date such Additional Guarantor’s execution of this Supplement and the delivery of this Supplement to the Agent on behalf of the Guaranteed Creditors, and that upon such execution and delivery, all references in the Guaranty to the terms “Guarantor” or “Guarantors” shall be deemed to include such Additional Guarantor.

          2. Each Additional Guarantor hereby assumes and becomes liable (jointly and severally with all the other Guarantors) for the indebtedness hereby guaranteed (as defined in the Guaranty) and agrees to pay and otherwise perform all of the obligations of a Guarantor under the Guaranty according to, and otherwise on and subject to, the terms and conditions of the Guaranty to the same extent and with the same force and effect as if the such Guarantor had originally been one of the Existing Guarantors under the Guaranty and had originally executed the same as such an Existing Guarantor.

          3. Without limiting the generality of the foregoing, each Guarantor acknowledges receipt of a copy of the Credit Agreement and hereby consents to and agrees with all of the terms, conditions and transactions contemplated thereunder and agrees that the amendment and restatement of the Prior Credit Agreement shall have no effect on the obligations of each Guarantor pursuant to the Guaranty.

          4. Each Guarantor confirms that the Guaranty and all of such Guarantor’s obligations thereunder remain in full force and effect and, without limiting the foregoing, each Guarantor acknowledges and agrees that loans and advances and other credit extended under the Credit Agreement shall constitute “indebtedness hereby guaranteed”, as such term is defined in the Guaranty, and that is guaranteed by the Guarantors under the Guaranty. All references to the terms “Credit Agreement” contained in the Guaranty shall be deemed references to the terms “Credit Agreement” as defined herein. All references to “Borrowers” contained in the Guaranty shall be deemed references to the Company, EMCOR UK and any other subsidiary of the Company that is designated as a Borrower under the Credit Agreement.

          5. Each Guarantor hereby reaffirms all of the terms, provisions, agreements and covenants contained in the Guaranty.

          6. The Guarantors agree to execute and deliver such further instruments and documents and do such further acts and things as the Agent may deem necessary or proper to carry out more effectively the purposes of this Supplement.

          7. This Supplement may be executed in any number of counterparts and by different parties hereto on separate counterparts, each of which when so executed shall be an original but

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