<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2024 Workiva-->
<!--r:a15e37b5-5dee-4e61-8f34-6928a0ceceb9,g:43fc9036-d1f6-49f8-baa0-b54e2e42d503-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:eme="http://www.emcorgroup.com/20240331" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types1="http://www.xbrl.org/dtr/type/2020-01-21" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2022-03-31" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.emcorgroup.com/20240331">
  <xs:import namespace="http://fasb.org/srt/2023" schemaLocation="https://xbrl.fasb.org/srt/2023/elts/srt-2023.xsd"/>
  <xs:import namespace="http://fasb.org/us-gaap/2023" schemaLocation="https://xbrl.fasb.org/us-gaap/2023/elts/us-gaap-2023.xsd"/>
  <xs:import namespace="http://www.w3.org/1999/xlink" schemaLocation="http://www.xbrl.org/2003/xlink-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/dtr/type/2020-01-21" schemaLocation="https://www.xbrl.org/dtr/type/2020-01-21/types.xsd"/>
  <xs:import namespace="http://www.xbrl.org/dtr/type/2022-03-31" schemaLocation="https://www.xbrl.org/dtr/type/2022-03-31/types.xsd"/>
  <xs:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/country/2023" schemaLocation="https://xbrl.sec.gov/country/2023/country-2023.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/dei/2023" schemaLocation="https://xbrl.sec.gov/dei/2023/dei-2023.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/ecd/2023" schemaLocation="https://xbrl.sec.gov/ecd/2023/ecd-2023.xsd"/>
  <xs:annotation>
    <xs:appinfo>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="eme-20240331_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="eme-20240331_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="eme-20240331_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="eme-20240331_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:type="simple"/>
      <link:roleType id="DocumentAndEntityInformation" roleURI="http://www.emcorgroup.com/role/DocumentAndEntityInformation">
        <link:definition>0000001 - Document - Document And Entity Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ConsolidatedBalanceSheets" roleURI="http://www.emcorgroup.com/role/ConsolidatedBalanceSheets">
        <link:definition>0000002 - Statement - Consolidated Balance Sheets</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ConsolidatedBalanceSheetsParenthetical" roleURI="http://www.emcorgroup.com/role/ConsolidatedBalanceSheetsParenthetical">
        <link:definition>0000003 - Statement - Consolidated Balance Sheets (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedStatementsOfOperations" roleURI="http://www.emcorgroup.com/role/CondensedConsolidatedStatementsOfOperations">
        <link:definition>0000004 - Statement - Condensed Consolidated Statements Of Operations</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedStatementsOfComprehensiveIncome" roleURI="http://www.emcorgroup.com/role/CondensedConsolidatedStatementsOfComprehensiveIncome">
        <link:definition>0000005 - Statement - Condensed Consolidated Statements Of Comprehensive Income</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedStatementsOfComprehensiveIncomeParenthetical" roleURI="http://www.emcorgroup.com/role/CondensedConsolidatedStatementsOfComprehensiveIncomeParenthetical">
        <link:definition>0000006 - Statement - Condensed Consolidated Statements Of Comprehensive Income (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedStatementsOfCashFlows" roleURI="http://www.emcorgroup.com/role/CondensedConsolidatedStatementsOfCashFlows">
        <link:definition>0000007 - Statement - Condensed Consolidated Statements Of Cash Flows</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedStatementsofCashFlowsParenthetical" roleURI="http://www.emcorgroup.com/role/CondensedConsolidatedStatementsofCashFlowsParenthetical">
        <link:definition>0000008 - Statement - Condensed Consolidated Statements of Cash Flows (Parenthetical)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CondensedConsolidatedStatementsOfEquity" roleURI="http://www.emcorgroup.com/role/CondensedConsolidatedStatementsOfEquity">
        <link:definition>0000009 - Statement - Condensed Consolidated Statements Of Equity</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="BasisOfPresentation" roleURI="http://www.emcorgroup.com/role/BasisOfPresentation">
        <link:definition>0000010 - Disclosure - Basis Of Presentation</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="NewAccountingPronouncements" roleURI="http://www.emcorgroup.com/role/NewAccountingPronouncements">
        <link:definition>0000011 - Disclosure - New Accounting Pronouncements</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomers" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomers">
        <link:definition>0000012 - Disclosure - Revenue from Contracts with Customers</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AcquisitionsOfBusinesses" roleURI="http://www.emcorgroup.com/role/AcquisitionsOfBusinesses">
        <link:definition>0000013 - Disclosure - Acquisitions Of Businesses</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EarningsPerShare" roleURI="http://www.emcorgroup.com/role/EarningsPerShare">
        <link:definition>0000014 - Disclosure - Earnings Per Share</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Inventories" roleURI="http://www.emcorgroup.com/role/Inventories">
        <link:definition>0000015 - Disclosure - Inventories</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="Debt" roleURI="http://www.emcorgroup.com/role/Debt">
        <link:definition>0000016 - Disclosure - Debt</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FairValueMeasurements" roleURI="http://www.emcorgroup.com/role/FairValueMeasurements">
        <link:definition>0000017 - Disclosure - Fair Value Measurements</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxes" roleURI="http://www.emcorgroup.com/role/IncomeTaxes">
        <link:definition>0000018 - Disclosure - Income Taxes</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommonStock" roleURI="http://www.emcorgroup.com/role/CommonStock">
        <link:definition>0000019 - Disclosure - Common Stock</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RetirementPlans" roleURI="http://www.emcorgroup.com/role/RetirementPlans">
        <link:definition>0000020 - Disclosure - Retirement Plans</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentsandContingencies" roleURI="http://www.emcorgroup.com/role/CommitmentsandContingencies">
        <link:definition>0000021 - Disclosure - Commitments and Contingencies</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AdditionalCashFlow" roleURI="http://www.emcorgroup.com/role/AdditionalCashFlow">
        <link:definition>0000022 - Disclosure - Additional Cash Flow</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SegmentInformation" roleURI="http://www.emcorgroup.com/role/SegmentInformation">
        <link:definition>0000023 - Disclosure - Segment Information</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomersPolicy" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomersPolicy">
        <link:definition>9954471 - Disclosure - Revenue from Contracts with Customers (Policy)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FairValueMeasurementsPolicy" roleURI="http://www.emcorgroup.com/role/FairValueMeasurementsPolicy">
        <link:definition>9954472 - Disclosure - Fair Value Measurements (Policy)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentandContingenciesPolicies" roleURI="http://www.emcorgroup.com/role/CommitmentandContingenciesPolicies">
        <link:definition>9954473 - Disclosure - Commitment and Contingencies (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomersTables" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomersTables">
        <link:definition>9954474 - Disclosure - Revenue from Contracts with Customers (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EarningsPerShareTables" roleURI="http://www.emcorgroup.com/role/EarningsPerShareTables">
        <link:definition>9954475 - Disclosure - Earnings Per Share (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="InventoriesTables" roleURI="http://www.emcorgroup.com/role/InventoriesTables">
        <link:definition>9954476 - Disclosure - Inventories (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FairValueMeasurementsTables" roleURI="http://www.emcorgroup.com/role/FairValueMeasurementsTables">
        <link:definition>9954477 - Disclosure - Fair Value Measurements (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesTables" roleURI="http://www.emcorgroup.com/role/IncomeTaxesTables">
        <link:definition>9954478 - Disclosure - Income Taxes (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RetirementPlansTables" roleURI="http://www.emcorgroup.com/role/RetirementPlansTables">
        <link:definition>9954479 - Disclosure - Retirement Plans (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AdditionalCashFlowInformationTables" roleURI="http://www.emcorgroup.com/role/AdditionalCashFlowInformationTables">
        <link:definition>9954480 - Disclosure - Additional Cash Flow Information (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SegmentInformationTables" roleURI="http://www.emcorgroup.com/role/SegmentInformationTables">
        <link:definition>9954481 - Disclosure - Segment Information (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomersDetails" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomersDetails">
        <link:definition>9954482 - Disclosure - Revenue from Contracts with Customers (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomersScheduleofCumulativeCatchUpAdjustmentDetails" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomersScheduleofCumulativeCatchUpAdjustmentDetails">
        <link:definition>9954483 - Disclosure - Revenue from Contracts with Customers - Schedule of Cumulative Catch-Up Adjustment (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomersScheduleofDisaggregationofRevenuesDetails" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomersScheduleofDisaggregationofRevenuesDetails">
        <link:definition>9954484 - Disclosure - Revenue from Contracts with Customers - Schedule of Disaggregation of Revenues (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomersScheduleofCreditLossesDetails" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomersScheduleofCreditLossesDetails">
        <link:definition>9954485 - Disclosure - Revenue from Contracts with Customers - Schedule of Credit Losses (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomersScheduleofContractwithCustomerAssetandLiabilityDetails" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomersScheduleofContractwithCustomerAssetandLiabilityDetails">
        <link:definition>9954486 - Disclosure - Revenue from Contracts with Customers - Schedule of Contract with Customer, Asset and Liability (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomersScheduleofRevenueRemainingPerformanceObligationsDetails" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomersScheduleofRevenueRemainingPerformanceObligationsDetails">
        <link:definition>9954487 - Disclosure - Revenue from Contracts with Customers - Schedule of Revenue, Remaining Performance Obligations (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomersScheduleofRevenueRemainingPerformanceObligationsExpectedTimingofSatisfactionDetails" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomersScheduleofRevenueRemainingPerformanceObligationsExpectedTimingofSatisfactionDetails">
        <link:definition>9954488 - Disclosure - Revenue from Contracts with Customers - Schedule of Revenue. Remaining Performance Obligations, Expected Timing of Satisfaction (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RevenuefromContractswithCustomersScheduleofRevenueRemainingPerformanceObligationsExpectedTimingofSatisfactionDetails_1" roleURI="http://www.emcorgroup.com/role/RevenuefromContractswithCustomersScheduleofRevenueRemainingPerformanceObligationsExpectedTimingofSatisfactionDetails_1">
        <link:definition>9954488 - Disclosure - Revenue from Contracts with Customers - Schedule of Revenue. Remaining Performance Obligations, Expected Timing of Satisfaction (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AcquisitionsOfBusinessesDetails" roleURI="http://www.emcorgroup.com/role/AcquisitionsOfBusinessesDetails">
        <link:definition>9954489 - Disclosure - Acquisitions Of Businesses (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="EarningsPerShareDetails" roleURI="http://www.emcorgroup.com/role/EarningsPerShareDetails">
        <link:definition>9954490 - Disclosure - Earnings Per Share (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="InventoriesDetails" roleURI="http://www.emcorgroup.com/role/InventoriesDetails">
        <link:definition>9954491 - Disclosure - Inventories (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DebtNarrativeDetails" roleURI="http://www.emcorgroup.com/role/DebtNarrativeDetails">
        <link:definition>9954492 - Disclosure - Debt (Narrative) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="FairValueMeasurementsScheduleOfAssetsAndLiabilitiesCarriedAtFairValueMeasuredOnARecurringBasisDetails" roleURI="http://www.emcorgroup.com/role/FairValueMeasurementsScheduleOfAssetsAndLiabilitiesCarriedAtFairValueMeasuredOnARecurringBasisDetails">
        <link:definition>9954493 - Disclosure - Fair Value Measurements (Schedule Of Assets And Liabilities Carried At Fair Value Measured On A Recurring Basis) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="IncomeTaxesDetails" roleURI="http://www.emcorgroup.com/role/IncomeTaxesDetails">
        <link:definition>9954494 - Disclosure - Income Taxes (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ScheduleofIncomeTaxProvisionDetails" roleURI="http://www.emcorgroup.com/role/ScheduleofIncomeTaxProvisionDetails">
        <link:definition>9954495 - Disclosure - - Schedule of Income Tax Provision (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommonStockDetails" roleURI="http://www.emcorgroup.com/role/CommonStockDetails">
        <link:definition>9954496 - Disclosure - Common Stock (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RetirementPlansNarrativeDetails" roleURI="http://www.emcorgroup.com/role/RetirementPlansNarrativeDetails">
        <link:definition>9954497 - Disclosure - Retirement Plans (Narrative) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RetirementPlansComponentsOfNetPeriodicPensionBenefitCostIncomeDetails" roleURI="http://www.emcorgroup.com/role/RetirementPlansComponentsOfNetPeriodicPensionBenefitCostIncomeDetails">
        <link:definition>9954498 - Disclosure - Retirement Plans (Components Of Net Periodic Pension Benefit Cost (Income)) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="CommitmentsandContingenciesNarrativeDetails" roleURI="http://www.emcorgroup.com/role/CommitmentsandContingenciesNarrativeDetails">
        <link:definition>9954499 - Disclosure - Commitments and Contingencies Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="AdditionalCashFlowInformationDetails" roleURI="http://www.emcorgroup.com/role/AdditionalCashFlowInformationDetails">
        <link:definition>9954500 - Disclosure - Additional Cash Flow Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SegmentInformationDetails" roleURI="http://www.emcorgroup.com/role/SegmentInformationDetails">
        <link:definition>9954501 - Disclosure - Segment Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xs:appinfo>
  </xs:annotation>
  <xs:element id="eme_GovernmentSiteBasedServicesMember" abstract="true" name="GovernmentSiteBasedServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_UnitedStatesSubsidiariesMember" abstract="true" name="UnitedStatesSubsidiariesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_Noncashsharebasedcompensationexpense" abstract="false" name="Noncashsharebasedcompensationexpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_ShortDurationProjectsMember" abstract="true" name="ShortDurationProjectsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_TransportationMarketSectorMember" abstract="true" name="TransportationMarketSectorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_NumberOfOperatingSubsidiaries" abstract="false" name="NumberOfOperatingSubsidiaries" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="eme_RevenueFromContractsWithCustomersTableTable" abstract="true" name="RevenueFromContractsWithCustomersTableTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="eme_CreditAgreement2023Member" abstract="true" name="CreditAgreement2023Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="eme_AggregateEstimatedExposureContractsWithSuretyBonds" abstract="false" name="AggregateEstimatedExposureContractsWithSuretyBonds" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_UnitedStatesElectricalConstructionAndFacilitiesServicesMember" abstract="true" name="UnitedStatesElectricalConstructionAndFacilitiesServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_RevolvingCreditFacilityBaseRateFederalFundsRateMember" abstract="true" name="RevolvingCreditFacilityBaseRateFederalFundsRateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_PercentageOfIndividualSegmentRevenues" abstract="false" name="PercentageOfIndividualSegmentRevenues" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="eme_CashPaidForAbstract" abstract="true" name="CashPaidForAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="eme_IncreaseBorrowingCapacity" abstract="false" name="IncreaseBorrowingCapacity" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_BusinessCombinationRecognizedWorkingCapital" abstract="false" name="BusinessCombinationRecognizedWorkingCapital" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_AggregateEstimatedExposureRPO1" abstract="false" name="AggregateEstimatedExposureRPO1" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="eme_UnitedStatesIndustrialServicesMember" abstract="true" name="UnitedStatesIndustrialServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_RevenueRemainingPerformanceObligationTableTextBlock" abstract="false" name="RevenueRemainingPerformanceObligationTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:textBlockItemType"/>
  <xs:element id="eme_RevolvingCreditFacilityBaseRateAdjustedSOFROneMonthTenorRateMember" abstract="true" name="RevolvingCreditFacilityBaseRateAdjustedSOFROneMonthTenorRateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_HospitalityandEntertainmentMarketSectorMember" abstract="true" name="HospitalityandEntertainmentMarketSectorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_UnitedStatesBuildingServicesMember" abstract="true" name="UnitedStatesBuildingServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_NumeratorEarningsPerShareAbstract" abstract="true" name="NumeratorEarningsPerShareAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="eme_HighTechManufacturingMarketSectorMember" abstract="true" name="HighTechManufacturingMarketSectorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_ContractWithCustomerCumulativeCatchUpAdjustmentChangeInMeasureOfProgress" abstract="false" name="ContractWithCustomerCumulativeCatchUpAdjustmentChangeInMeasureOfProgress" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_CommercialSiteBasedServicesMember" abstract="true" name="CommercialSiteBasedServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_CreditAgreementExpirationDate1" abstract="false" name="CreditAgreementExpirationDate1" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:dateItemType"/>
  <xs:element id="eme_CommercialMarketSectorMember" abstract="true" name="CommercialMarketSectorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_RevolvingCreditFacility0BaseRateMember" abstract="true" name="RevolvingCreditFacility0BaseRateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_ServiceWorkMember" abstract="true" name="ServiceWorkMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_WaterandWastewaterMarketSectorMember" abstract="true" name="WaterandWastewaterMarketSectorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_ContractLiabilitiesNet" abstract="false" name="ContractLiabilitiesNet" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_PaymentsforContingentConsiderationArrangements" abstract="false" name="PaymentsforContingentConsiderationArrangements" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_A2024AcquisitionsMember" abstract="true" name="A2024AcquisitionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="eme_DefinedBenefitPlanNumberOfPlans" abstract="false" name="DefinedBenefitPlanNumberOfPlans" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="eme_DefinedBenefitPlanNetPeriodicBenefitCostExcludingServiceCost" abstract="false" name="DefinedBenefitPlanNetPeriodicBenefitCostExcludingServiceCost" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_RevenueFromContractWithCustomersLineItemsLineItems" abstract="true" name="RevenueFromContractWithCustomersLineItemsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="eme_CumulativeCatchUpAdjustmentTable" abstract="true" name="CumulativeCatchUpAdjustmentTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="eme_LettersOfCreditMaximumBorrowingCapacity" abstract="false" name="LettersOfCreditMaximumBorrowingCapacity" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_A2023AcquisitionsMember" abstract="true" name="A2023AcquisitionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="eme_InstitutionalMarketSectorMember" abstract="true" name="InstitutionalMarketSectorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_UnitedKingdomBuildingServicesMemberMember" abstract="true" name="UnitedKingdomBuildingServicesMemberMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_RevolvingCreditFacility2023Member" abstract="true" name="RevolvingCreditFacility2023Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="eme_UnitedStatesMechanicalConstructionAndFacilitiesServicesMember" abstract="true" name="UnitedStatesMechanicalConstructionAndFacilitiesServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_FieldServicesMember" abstract="true" name="FieldServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_ContractWithCustomerCumulativeCatchUpAdjustmentChangeInMeasureOfProgressTableTextBlock" abstract="false" name="ContractWithCustomerCumulativeCatchUpAdjustmentChangeInMeasureOfProgressTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="eme_RangeOfLetterOfCreditFees" abstract="false" name="RangeOfLetterOfCreditFees" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="eme_UnitedKingdomSubsidiaryMember" abstract="true" name="UnitedKingdomSubsidiaryMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_ScheduleofRemainingPerformanceObligationsLineItems" abstract="true" name="ScheduleofRemainingPerformanceObligationsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="eme_NetworkandCommunicationsMarketSectorMember" abstract="true" name="NetworkandCommunicationsMarketSectorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_CumulativeCatchUpAdjustmentLineItems" abstract="true" name="CumulativeCatchUpAdjustmentLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="eme_ShopServicesMember" abstract="true" name="ShopServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_ContractwithCustomerNetLiabilitiesIncrease" abstract="false" name="ContractwithCustomerNetLiabilitiesIncrease" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_CreditAgreementInitiationDate1" abstract="false" name="CreditAgreementInitiationDate1" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:dateItemType"/>
  <xs:element id="eme_ProjectWorkMember" abstract="true" name="ProjectWorkMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_DenominatorEarningsPerShareAbstract" abstract="true" name="DenominatorEarningsPerShareAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="eme_ManufacturingandIndustrialMarketSectorMember" abstract="true" name="ManufacturingandIndustrialMarketSectorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_BusinessAcquisitionPurchasePriceAllocationGoodwillIdentifiableIntangibleAssetsExpectedTaxDeductibleAmount" abstract="false" name="BusinessAcquisitionPurchasePriceAllocationGoodwillIdentifiableIntangibleAssetsExpectedTaxDeductibleAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_EstimatedInsuranceRecoveriesCurrent" abstract="false" name="EstimatedInsuranceRecoveriesCurrent" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_MechanicalServicesMember" abstract="true" name="MechanicalServicesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_HealthcareMarketSectorMember" abstract="true" name="HealthcareMarketSectorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_AdjustedTermSOFRMember" abstract="true" name="AdjustedTermSOFRMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="eme_SuretyBondsForInsurance" abstract="false" name="SuretyBondsForInsurance" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_BusinessCombinationRecognizedOtherNetLiabilities" abstract="false" name="BusinessCombinationRecognizedOtherNetLiabilities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="eme_ScheduleofRemainingPerformanceObligationsTable" abstract="true" name="ScheduleofRemainingPerformanceObligationsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="eme_DividendsCommonStock1" abstract="false" name="DividendsCommonStock1" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
