#1ACCON THIRD QUARTER 2023 AECON GROUP INC. (TSX: ARE)#2Forward-Looking Information Non-GAAP & Supplementary Financial Measures The information in this presentation includes certain forward-looking statements which may constitute forward-looking information under applicable securities laws. These forward-looking statements are based on currently available competitive, financial and economic data and operating plans but are subject to risks and uncertainties. Forward-looking statements may include, without limitation, statements regarding the operations, business, financial condition, expected financial results, performance, prospects, ongoing objectives, strategies and outlook for Aecon, including statements regarding: Oaktree's minority investment in Aecon Utilities, the expected benefits thereof and results therefrom, including the acceleration of growth of Aecon Utilities in Canada and the U.S.; the anticipated use of proceeds from Oaktree's minority investment in Aecon Utilities; the expansion of Aecon Utilities' geographic reach and range of services in the U.S.; Aecon Utilities' goal of targeting prudent balance sheet leverage and liquidity; expectations regarding significant opportunities arising from the Inflation Reduction Act (IRA) and Bipartisan Infrastructure Law (BIL) in the U.S.; its strategic focus on clean energy and other projects linked to sustainability and the opportunities arising therefrom; the impact of Aecon's recurring revenue base; potential value creation options, estimated costs and timelines for projects; the various phases of projects for Aecon; Aecon's greenhouse gas emission reduction targets and means to accomplish such targets; government investment; expectations regarding strong private sector end market demand due to, among other things, aging electrical and gas infrastructure and North American 5G adoption rate; expectations regarding ongoing recovery in travel through Bermuda International Airport in 2023; long-term cash flow and growth opportunities in concessions including opportunities to add to the existing portfolio of Canadian and international concessions in the next 12 to 24 months; expectations regarding the repayment of the outstanding convertible debentures at or before maturity and other debt obligations in 2023; expectations regarding the continued impact of inflation, interest rates and supply chain efficiency; expectations regarding the pipeline of opportunities available to Aecon and project pursuits; expectations regarding future revenue growth and the impact therefrom; expectations regarding the impact of the four fixed price legacy projects; Aecon's expectations of being able to strengthen its balance sheet while preserving capital for other long-term growth and concession opportunities; and, future dividends. Forward-looking statements may in some cases be identified by words such as "will," "believes," "target," "expects," "anticipates," "estimates," "towards," "opportunity," "projects," "intends," "schedule," "outlook," "can," "may," "to be," "upon," "should" or the negative of these terms, or similar expressions. In addition to events beyond Aecon's control, there are factors which could cause actual or future results, performance or achievements to differ materially from those expressed or inferred herein including, but not limited to: the risk of not being able to drive a higher margin mix of business by participating in more complex projects, achieving operational efficiencies and synergies, and improving margins; the risk of not being able to meet contractual schedules and other performance requirements on large, fixed priced contracts; the risk of not being able to meet its labour needs at reasonable costs; the risk of not being able to address any supply chain issues which may arise and pass on costs of supply increases to customers; the risk of not being able, through its joint ventures, to enter into implementation phases of certain projects following the successful completion of the relevant development phase; the risk of not being able to execute its strategy of building strong partnerships and alliances; the risk of not being able to execute its risk management strategy; the risk of not being able to grow backlog across the organization by winning major projects; the risk of not being able to maintain a number of open, recurring and repeat contracts; the risk of not being able to accurately assess the risks and opportunities related to its industry's transition to a lower-carbon economy; the risk of not being able to oversee, and where appropriate, respond to known and unknown environmental and climate change-related risks, including the ability to recognize and adequately respond to climate change concerns or public, governmental and other stakeholders' expectations on climate matters; the risk of not being able to meet its commitment to meeting its greenhouse gas emissions reduction targets; the risks associated with the strategy of differentiating its service offerings in key end markets; the risks associated with undertaking initiatives to train employees; the risks associated with the seasonal nature of its business; the risks associated with being able to participate in large projects; the risks associated with legal proceedings to which it is a party; the ability to successfully respond to shareholder activism; the risk that the strategic partnership with Green Infrastructure Partners Inc. ("GIP") will not realize the expected results and may negatively impact Aecon's existing business; the risk that Aecon will not realize the anticipated balance sheet flexibility with the completion of the sale of ATE; the risk that Aecon will not realize the opportunities presented by a transition to a net-zero economy; the risk that Aecon will not realize the strategic rationale for the sale of the equity interest in Skyport; the risk that the strategic partnership with Oaktree will not realize the expected results and may negatively impact the existing business of Aecon Utilities; the risk that Aecon will not realize the anticipated balance sheet flexibility with the completion of the sale of minority interest in Aecon Utilities; the risk that Aecon Utilities will not realize opportunities to expand its geographic reach and range of services in the U.S.; the risk that Aecon will not realize the anticipated balance sheet strength while preserving capital for other long-term growth and concession opportunities in connection with the sale of the equity interest in Skyport; and risks associated with the COVID-19 pandemic and future pandemics and Aecon's ability to respond to and implement measures to mitigate the impact of COVID-19 and future pandemics. These forward-looking statements are based on a variety of factors and assumptions including, but not limited to that: none of the risks identified above materialize, there are no unforeseen changes to economic and market conditions and no significant events occur outside the ordinary course of business. These assumptions are based on information currently available to Aecon, including information obtained from third-party sources. While Aecon believes that such third-party sources are reliable sources of information, Aecon has not independently verified the information, Aecon has not ascertained the validity or accuracy of the underlying economic assumptions contained in such information from third-party sources and hereby disclaims any responsibility or liability whatsoever in respect of any information obtained from third-party sources. Risk factors are discussed in greater detail in the Section 13 - "Risk Factors" in Aecon's December 31, 2022 Management's Discussion and Analysis filed on SEDAR+ (www.sedarplus.com) on February 28, 2023 and in other filings made by Aecon with the securities regulatory authorities in Canada. Except as required by applicable securities laws, forward-looking statements speak only as of the date on which they are made and Aecon undertakes no obligation to publicly update or revise any forward-looking statement, whether as a result of new information, future events or otherwise. ACCON The presentation presents certain non-GAAP and supplementary financial measures, as well as non-GAAP ratios and capital management measures disclosed to assist readers in understanding the Company's performance ("GAAP" refers to Canadian Generally Accepted Accounting Principles under IFRS). These measures do not have any standardized meaning and therefore are unlikely to be comparable to similar measures presented by other issuers and should not be considered in isolation or as a substitute for measures of performance prepared in accordance with GAAP. Management uses these non-GAAP and supplementary financial measures, as well as certain non-GAAP ratios and capital management measures to analyze and evaluate operating performance. Aecon also believes the financial measures defined below are commonly used by the investment community for valuation purposes, and are useful complementary measures of profitability, and provide metrics useful in the construction industry. The most directly comparable measures calculated in accordance with GAAP are profit (loss) attributable to shareholders or earnings (loss) per share. Throughout this presentation, the following terms are used, which do not have a standardized meaning under GAAP: "Adjusted EBITDA", "Equity Project EBITDA", "Backlog" and "Adjusted EBITDA margin." "Operating margin" and "Gross profit margin" are a supplementary financial measures. Refer to Section 4 "Non-GAAP and Supplementary Financial Measures" and Section 9 "Quarterly Financial Data" in the Company's September 30, 2023 Management's Discussion and Analysis, filed October 25, 2023 (the "Q3 2023 MD&A") for additional information regarding the non-GAAP and supplementary financial measures and non-GAAP ratios used in this presentation. Also refer to pages 17 and 27 in this presentation for additional information regarding non-GAAP ratios and capital management measures. The Q3 2023 MD&A is available on SEDAR+ (www.sedarplus.com), and the additional information regarding the non-GAAP and supplementary financial measures and non-GAAP ratios used in this presentation information in the above noted sections is incorporated by reference into this presentation. 2#3• Why Invest in Aecon? POSITIONED TO HARNESS OPPORTUNITIES THAT ARE EXPECTED TO COME WITH THE TRANSITION TO A NET ZERO ECONOMY Favourable Demand Environment * Diversified & Resilient Business Model Shareholder Value Creation CONSOLIDATED* CONSTRUCTION CONCESSIONS $4.8B $4.7B TOTAL REVENUE* NEW AWARDS* $6.2B BACKLOGⓇ ADJ. EBITDA*@ $141M $92M $89M (at Sep 30, 2023) OPERATING PROFIT** $242M $54M $177M Significant level of infrastructure investment underway across Aecon's focus areas Positive population and immigration dynamics helping to drive demand Transition to net zero economy creating opportunities in both public and private sectors Canada's exposure to resources sector driving additional demand in private sector Significant opportunities through Inflation Reduction Act (IRA) and Bipartisan Infrastructure Law (BIL) in the U.S. Historically, government investment in infrastructure has been a key source of stimulus in economic slowdowns • . Diversified projects by geography, sector, contract size and type in Construction segment • ~900 discrete projects underway with average project size $25 million • Growing number of projects in Concessions portfolio • • Recurring revenue base adds further stability and growth opportunity to business mix 54% of Q3 2023 TTM revenue from non-fixed price contracts versus 49% of Q3 2022 TTM revenue Positioned to harness expected opportunities linked to sustainability and the transition to a net zero economy • • 9% 10 YEAR DIVIDEND CAGR 60% OF 2022 REVENUE TIED TO SUSTAINABILITY PROJECTS# 71% OF BACKLOG TIED TO SUSTAINABILITY PROJECTS#& History of regular dividend increases ACQUISITIONS 8 IN THE ENERGY TRANSITION Strategic investment in Aecon Utilities in Q3 2023 by Oaktree to drive growth across utility end-markets in Canada and the U.S. and valuing Aecon Utilities at $750M (~ 9.3x TTM Adjusted EBITDA multiple) Strategic disposition of Aecon's Transportation East ("ATE") business in Q2 2023 at a ~8 - 9x TTM Adjusted EBITDA multiple @2 Growth in Concessions and O&M portfolio provides future revenue generating opportunities Focused on sustainability, including 30% GHG reduction target on an intensity basis by 2030 as compared to 2020 and net zero target by 2050 Q3 2023 Trailing Twelve Months ("TTM"). * Consolidated operating profit includes gains related to the sale of Aecon Transportation East ("ATE") ($36.5 million) and the sale of a 49.9% interest in the Bermuda International Airport concessionaire of $139 million, including a fair value remeasurement gain of $80.4 million on Aecon's 50.1% retained interest in the concessionaire, reported in the Concessions segment. + After corporate costs and eliminations. ACCON Compound Annual Growth Rate ("CAGR") of annual dividend from 2013 to 2022. & September 30, 2023 This is a non-GAAP financial measure. Refer to page 2 in this presentation. Σ Represents the implied $750 million enterprise value for Aecon Utilities divided by Q2 2023 TTM Adj. EBITDA of $80.4M. 2 Represents the implied $235 million enterprise value divided by 2022 Adj. EBITDA. # Sustainability projects help to preserve and protect the environment, but also help to preserve the ability of society to sustain itself. Including but not limited to projects that: reduce emissions, support the transition to a net-zero economy, support clean water use and conservation, and reduce/recycle waste. * Strategic, tuck-in acquisitions made over the past four years related to clean energy and transition to a net zero economy through decarbonization. * Intensity based targets are based on economic output and represent tonnes of CO2 per million dollars of revenue. 3#4Diverse Business Model Q3 2023 TTM Revenue Q3 2023 TTM Operating Profit $4,692 M+ $92 M+ $54 M+ Concessions Construction 03 2023 TIMA, EBITDA Urban Transportation Solutions 13%* Civil 31%* ACCON رہہ Nuclear Power 15%* SKYPORT * Utilities 19%* MOSAIC TRANSIT GROUP ONXPRESS TRANSPORTATION PARTNERS HOW NNI& CROSSLIN TRANSIT SOLUTIONS BRIDGING NORTHAMERICA Industrial 22%* GRANDLINQ CONTRACTORS Q3 2023 TTM Revenue Q3 2023 TTM Adj. EBITDA Q3 2023 TTM Operating Profit $91 M+ $89 M+ @ $177 M** BERMUDA INTERNATIONAL AIRPORT 50.1%^% FINCH WEST LRT 33.3% GO RAIL NETWORK ON-CORRIDOR 28.0%^ EGLINTON LRT 25.0%^ GORDIE HOWE INTERNATIONAL BRIDGE 20.0%^ WATERLOO LRT 10.0%^ ONEIDA ENERGY STORAGE L.P. 8.35%^ + Before corporate costs and eliminations. * % of Q3 2023 TTM Construction revenue; Civil sector includes Roads and Highways operations, which contributed 9% of Construction segment revenue. ^ % of Aecon equity ownership in Infrastructure Project Companies and Operators. * CC&L Infrastructure acquired a 49.9% interest in the concessionaire, which closed in Q3 2023. Aecon Concessions retains the management contract for the airport and joint control of Skyport with a 50.1% retained interest. This is a non-GAAP financial measure. Refer to page 2 in this presentation. * Operating profit for Concessions segment includes a gain related to the sale of a 49.9% interest in the Bermuda International Airport concessionaire of $139 million, including a fair value remeasurement gain of $80.4 million on Aecon's 50.1% retained interest in the concessionaire.#5Overview of Aecon Utilities Large and diverse utility infrastructure provider in Canada with a growing U.S. presence Financial Highlights 19%^ of Aecon's Construction Segment Revenue in Q3'23 TTM Period $361M Backlog at Q3'23 24% Electrical Transmission & Distribution Services for substations, tower assembly and installation, including high-voltage transmission Diversified Business Across Key End Markets 20% Renewables/ In-Home Services Solar, GeoExchange, battery storage, smart home, hybrid 27% Telecom Turnkey fibre installation, legacy network and 5G network expansion heating and HVAC US Expansion $693M Q3'23 TTM Recurring Revenue (75% of Total Aecon Utilities Revenue) 29% Pipeline Distribution Natural gas gathering systems, distribution services maintenance, facilities construction, water distribution Significant opportunities through Inflation Reduction Act (IRA) and Bipartisan Infrastructure Law (BIL) Energy Transition Energy transition is a key theme in all of Aecon Utilities' core end-markets Revenue ($M) $918 $928 19% CAGR $82M @ $810 $647 $550 Q3'23 TTM Adjusted EBITDA 2019A 2020A 2021A 2022A Q3' 23 TTM ACCON ^ After Construction segment intercompany eliminations for Aecon Utilities This is a non-GAAP financial measure. Refer to page 2 in this presentation. LO#6Oaktree's Investment in Aecon Utilities Highlights and unlocks the value of Aecon Utilities; investment represents valuation of ~9.3x TTM Adjusted EBITDA @ STRATEGIC RATIONALE • • Investment Amount & Overview Dividend Rate and Structure Aecon Utilities Rights • Oaktree's Minority Investment in Aecon Utilities $150 million Preferred Equity ($750 million enterprise value resulting in an as-converted ownership of 27.5%). Strengthens Aecon's consolidated balance sheet and provides financial flexibility to fund strategic growth initiatives. The Preferred Equity will carry a 12% dividend rate (payable in kind or cash at Aecon's option) for the first 3 years, increasing to 14% thereafter. Aecon has the option to redeem the Preferred Equity for cash at any time at a value equivalent to the greatest of: (a) the as-converted value of the Preferred Equity, (b) the accreted value of the Preferred Equity, and (c) 1.5x the Net Investment Amount less all cash dividends and distributions paid to Oaktree. Aecon will have four board members on Aecon Utilities' new six-person Board. Overview of Oaktree Oaktree is a leader among global investment managers specializing in alternative investments, with US$179 billion in assets under management. The firm emphasizes an opportunistic, value-oriented and risk-controlled approach to investments in credit, private equity, real assets and listed equities. The firm has over 1,100 employees and offices in 20 cities worldwide. In 2019, Brookfield Asset Management acquired a majority interest in Oaktree. Together, Brookfield and Oaktree provide investors with one of the most comprehensive offerings of alternative investment products available today. While partnering to leverage one another's strengths, Oaktree operates as an independent business within the Brookfield family, with its own product offerings and investment, marketing, and support teams. ACCON This is a non-GAAP financial measure. Refer to page 2 in this presentation. Σ Represents the implied $750 million enterprise value for Aecon Utilities divided by Q2 2023 TTM Adj. EBITDA of $80.4M *The gross subscription amount is $154.6 million, which represents $150.0 million after upfront fees. Creates a vehicle to accelerate Aecon Utilities' growth Oaktree is a highly respected institution and a value-added partner with significant experience to help Aecon Utilities reach its full potential Capitalize on attractive industry tailwinds, including decarbonization, sustainability and the energy transition Leverage Oaktree's network of industry relationships and extensive resources to continue growing in the U.S. Standalone capital structure provides the financial flexibility to capitalize on attractive M&A opportunities Highlights and unlocks the value of Aecon Utilities at $750M enterprise value and ~9.3x TTM Adjusted EBITDA multiple @ Immediately strengthens Aecon's balance sheet and capital position 6#7Highlighting Value Through Other Strategic Monetization Transactions strengthen balance sheet and complement strategic focus on investments in end markets related to energy transition and sustainability Sale of Aecon Transportation East Business To Green Infrastructure Partners Price & Overview Strategic Cooperation Agreement • 100% sale of Aecon Transportation East Business ("ATE”) to Green Infrastructure Partners Inc. ("GIP") for $235 million representing TTM Adjusted EBITDA multiple of ~8-9x ATE comprised of Aecon's roadbuilding, aggregates and materials businesses in Ontario and represented ~7% of Aecon's 2022 revenue Aecon and GIP have entered into a strategic cooperation agreement for certain major projects and pursuits in Ontario that leverages both Aecon's heavy civil construction services and GIP's roadbuilding capabilities 49.9% Sale of Bermuda International Airport Concessionaire To CC&L Infrastructure Price & Overview Management Structure Sale of 49.9% interest in the L.F. Wade International Airport (Bermuda International Airport) concessionaire, Bermuda Skyport Corporation Limited ("Skyport") to Connor, Clark & Lunn Infrastructure ("CC&L Infrastructure") for US$120 million in cash Aecon Concessions has retained the management contract for the airport and joint control of Skyport with a 50.1% retained interest Approvals • Closed on May 1, 2023 and Timing Approvals Closed on September 20, 2023 and Timing Strategic Rationale Shift towards opportunities related to decarbonization, energy transition and sustainability Consistent with Aecon's goal of targeting prudent balance sheet leverage and liquidity Helps reduce overall capital intensity of Aecon's business Strategic Rationale Highlights value of the Bermuda International Airport concession and underlines the contribution of the Concessions' portfolio of projects to Aecon Further strengthens Aecon's balance sheet while preserving capital for other long-term growth and concession opportunities Partnership with an experienced infrastructure investment firm demonstrates investor confidence in the future of Bermuda's long-term prospects ACCON This is a non-GAAP financial measure. Refer to page 2 in this presentation. Represents the implied $235 million enterprise value for ATE divided by 2022 Adj. EBITDA. 7#8Focused On Energy Transition Opportunities • • 60% of 2022 Revenue Tied To Sustainability Projects# Focused on various stages of the value chain in building the resilient, low carbon and connected infrastructure of tomorrow Presence in key markets across Canada and long-term relationships with clients across focused operating sectors Utilities Civil & Industrial Nuclear Urban Transportation Solutions • Electricity Transmission & Distribution • Water Distribution & • Small Modular Reactors • Light Rail Transit Management Refurbishment & . • Grid Modernization/Hardening . Hydroelectricity Decommissioning • • • Geothermal & District Energy / Renewables Energy Storage EV Charging Infrastructure Fibre and Broadband/ Telecom Infrastructure & 5G Hydrogen & Renewable Natural Gas Maintenance & Fabrication Services • Carbon Capture and Storage • Nuclear Waste Management High Speed Rail Expansion and electrification of Go-transit system in Ontario including 25-year O&M contract • Rare Metals & Battery Material Mining Facilities • In-Home Services ONRSTOR ACCON TESLA Oneida Energy Storage Project Site C Clean Energy Project Bruce Power Fuel Channel and Feeder Replacement GO Rail Expansion On-Corridor Works ACCON # Sustainability projects help to preserve and protect the environment, but also help to preserve the ability of society to sustain itself. Including but not limited to, projects that: reduce emissions, support the transition to a net-zero economy, support clean water use and conservation, and reduce/recycle waste. 8#9Solid Backlog & Growing Recurring Revenue Profile Current backlog excludes Aecon's share of the GO Expansion On Corr, Scarborough Subway Extension SRS and Darlington SMR projects Total BacklogⓇ ($M) At September 30 Backlog Duration ($M) Recurring Revenue ($M) At September 30 $6,043 $6,275 $6,202 $6,043 $6,275 $6,202 $667 $803 $1,124 $96 $78 $102 $1,306 $84 $1,866 $2,006 $1,732 $69 $1,479 $1,378 $57 $5,965 $6,179 $6,100 2021 2022 2023 ■Construction ■Concessions $1,040 $734 $3,237 $610 $2,857 $2,659 2021 2022 2023 12 Months 13-24 Months Beyond 24 Months 47% Fixed Price (58% at September 30, 2022) Backlog Contract Type At September 30, 2023 53% Cost Plus/ Unit Price (42% at September 30, 2022) 46% Fixed Price (51% same period last year) Q3 2023 TTM Revenue+ *These projects were awarded in a collaborative model and are currently in the development and alliance phases. Further detail on these projects is provided on Slide 10. + TTM Revenue contract mix reflects inclusion of recurring revenue (Cost Plus/Unit Price) and timing of backlog work off. This is a non-GAAP financial measure. Refer to page 2 in this presentation. ACCON Q3 2021 TTM Q3 2022 TTM Q3 2023 TTM ■Construction ■Concessions 54% Cost Plus/Unit Price (49% same period last year)#10De-Risking Business Through Collaborative Models Sustainability linked projects currently in development phases present significant opportunities for long term growth* GO Rail Expansion On-Corridor (OnCorr) Works Project Estimated Total Capital Cost: >$10B^& Progressive Design, Build, Operate & Maintain Model ONxpress Transportation Partners (ONxpress) selected to design, build, operate and maintain the GO Expansion OnCorr Works project in Ontario Progressive and collaborative design, build, operate and maintain model ONxpress consortium comprised of Aecon, FCC, Deutsche Bahn and Alstom Aecon 50% share in a civil JV with FCC, and 28% share in a 25-year O&M partnership with Deutsche Bahn Early works and a two-year collaborative development phase commenced in Q3 2022, with O&M anticipated to commence in Q2 2024 Scarborough Subway Extension Stations, Rail and Systems (SRS) Estimated Design & Construction Cost: $2B - $4B*& Progressive Design-Build Model Scarborough Transit Connect (STC), a 50/50 consortium between Aecon (lead partner) and FCC, selected as the development partner for the Scarborough Subway Extension SRS project in Ontario Progressive and collaborative design-build model An 18-month collaborative development phase commenced in Q4 2022 to finalize the scope, cost and schedule of various elements of the project, with certain early works activities commencing during this phase Upon successful completion of the development phase, an implementation phase will commence under a target price contract Scarborough Sc Darlington New Nuclear Project (DNNP) Small Modular Reactor (SMR) Total Capital Cost Under Development Integrated Project Delivery Model Aecon, GE Hitachi and SNC-Lavalin executed a six-year alliance agreement with Ontario Power Generation (OPG) to deliver North America's first grid-scale SMR through the DNNP in Ontario Under an Integrated Project Delivery (IPD) model, OPG serves as the license holder and will maintain overall responsibility for the project, including operator training, commissioning, Indigenous engagement, stakeholder outreach and oversight Aecon is the provider of all construction services, including project management, construction planning and execution. Site preparation and related work is currently underway and SMR construction is expected to reach completion in the fourth quarter of 2028 ACCON # Projects would be added to backlog following completion of successful development phases over one to two years. Based on Infrastructure Ontario Market Update Report (January 2022); represents "Estimated Total Capital Costs" for the project, not Aecon's share in the project. *Based on Infrastructure Ontario Market Update Report (November 2022); represents "Estimated Design & Construction Cost" for the project, not Aecon's share in the project. & Estimated figures are not Aecon's shares in the projects as the work is performed in partnerships or joint ventures with other companies; Aecon's scope of work and relative value subject to change during the development phases. 10#11Major Projects & Concessions Provide Stability Project Timeline (Starting from 2023) 2023 Gordie Howe Bridge 2024 Finch West LRT Eglinton LRT GO On-Corridor Oneida Energy Storage Waterloo LRT Bermuda Airport Bruce Power Collaborative Development Phase Scarborough Subway Ext. Collaborative Development Phase Darlington New SMR Darlington Refurbishment Deerfoot Trail Improv. John Hart Dam Seismic Kingstown Port (St. Vincent) Giant Mine Remediation Pattullo Bridge Eglinton West Tunnel Winnipeg North End Buffalo Pound Water Treat. REM Montreal 2025 P3 Concessions/ DBOM* Gordie Howe Bridge Other Major Projects* Bruce Power Nuclear Refurbishment (55% JV) $1.7 billion Fuel Channel and Feeder Replacement contract for remaining five units at Bruce Nuclear $5.7 billion; construction started 2018; Generating Station with anticipated completion in 2032 20% equity stake and 30-year concession post construction Finch West LRT $2.5 billion; construction started 2018; 33.3% equity stake and 30-year concession post construction (at 50% share in construction JV) Scarborough Subway Extension SRS (50% JV) $2-4+ billion; project duration to be determined post collaborative design phase Darlington New Nuclear Project (SMR) Total Capital Cost Under Development; expected to reach completion in Q4 2028 Darlington Nuclear Refurbishment (50% JV) $5.3 billion; construction started 2015; $2.75 billion; ~10-year project started 2016 Deerfoot Trail Improvements Project $615 million; ~4-year project to be started in 2023 2026 2027 2028 2029 2030 Eglinton LRT 2054 2053 25% equity stake and 30-year 2052 concession post construction 2050 GO Rail Expansion - On-Corridor 2050 >$10 billion^; 28% interest in 25-year John Hart Dam Seismic Upgrade (60% JV) 2049 2047 >>>2032 O&M partnership post collaborative design phase; 50% interest in construction JV Oneida Energy Storage $141 million EPC contract; construction started 2023; 8.35% equity stake and 20-year electricity storage services agreement (plus 5-years uncontracted revenue) post construction Waterloo LRT $583 million; construction started 2014 and completed 2019; 10% equity stake and 30-year concession began in 2019 Bermuda Airport US$274 million; construction started 2017 and completed 2020; 50.1%% equity stake and 30-year concession began in 2017 $245 million; ~3-year project to be started in 2023 Kingstown (SVG) Port Modernization Project US$170 million; ~3-year project started 2022 Giant Mine Remediation Water Treatment Plant Project $215 million; ~3-year project to be started in 2023 Pattullo Bridge Replacement (50% JV) $968 million; ~5-year project started 2020 Eglinton Crosstown West Extension Tunnel (40% JV) $729 million; ~4-year project started 2021 Winnipeg North End Sewage Plant (50% JV) $272 million; ~4-year project started 2021 Buffalo Pound Water Treatment Plant (50% JV) $273 million; ~3-year project started 2022 REM LRT Montreal (24% JV) / REM LRT Airport Station (50% JV) $6.9 billion; ~6-year project started 2018 Construction Equity & Maintenance Equity, Operations & Maintenance Progressive Design, Build, Operations & Maintenance Progressive Design-Build Integrated Project Delivery Opportunity ACCON Dates above are general estimates of completion and may not reflect final completion dates. For information regarding risk related to construction delays, see Section 13 "Risk Factors" in the Q3 2023 MD&A. * Awarded contract values refer to the initial contract amount and do not account for any subsequent change orders which have resulted in an increase to the scope and/or price of the contract; awarded contract values do not necessarily represent Aecon's share, as all projects listed are with partners as of the date hereof except Bermuda Airport and Kingstown Port Modernization Project; construction duration of each project is approximate and subject to change. * CC&L Infrastructure acquired a 49.9% interest in the concessionaire, which closed in Q3 2023. Aecon Concessions retains the management contract for the airport and joint control of Skyport with a 50.1% retained interest. ^ Based on Infrastructure Ontario Market Update Report (January 2022); represents "Estimated Total Capital Costs" for the project, not Aecon's share in the project. + Based on Infrastructure Ontario Market Update Report (November 2022); represents "Estimated Design & Construction Cost" for the project, not Aecon's share in the project. 11#12Government Investment Aligned with Aecon's Strengths^ Federal Infrastructure Programs $180B Invest in Canada Plan* 12-year Federal investment plan 2016 to 2028 To date, the plan has invested over $142B in over 92,000 projects, 95% of them completed or underway $3.2B investment in Universal Broadband Fund to provide high-speed internet access to all Canadians by 2030 $35B Canada Infrastructure Bank $35B for the Canada Infrastructure Bank ("CIB") to attract private capital to major infrastructure projects and help build more infrastructure across the country Budget 2023 announced that the CIB will invest at least $10B through its clean power priority area, and at least $10B through its green infrastructure priority area $3B Supporting Clean Electricity Projects Budget 2023 proposed to provide $3 billion over 13 years to recapitalize funding for the Smart Renewables and Electrification Pathways Program to support critical regional priorities and Indigenous-led projects, and other green initiatives $15B Canada Growth Fund* To help build a net-zero economy by 2050 by accelerating the investment of private capital into decarbonization and clean technology projects ° $6.5B $0.6B $13B ° $0.4B $103B $47B Provincial Budgets $13B BC Budget Transportation investment over 3 years from 2023 $6.5B Alberta Budget Transportation and public transit investment over 3 years from 2023 $0.4B Saskatchewan Budget Transportation investment in 2023 $0.6B Manitoba Budget Transportation investment in 2023 $103B Ontario Budget $99B in Transit and Transportation investment over 10 years from 2023, including $28B in road and highways and $71B in transit $4B beginning in 2019 to provide high speed internet access to every community in Ontario by the end of 2025 $47B Quebec Budget Investment in road and transit infrastructure over 10 years from 2023 including $32B investment in roads ACCON Source: Infrastructure Canada, Canada Infrastructure Bank Investing in New Infrastructure Growth Plan 2020, Ontario Budget 2023, BC Budget 2023, Alberta Budget 2023, Quebec Budget 2023, Manitoba Budget 2023, Saskatchewan Budget 2023 # Source: Federal Budget 2023. 12#13Strong Public and Private End Market Demand CURRENT MAJOR PROJECT PURSUITS INCLUDE: Diversified series of pursuits by sector and geography | Opportunities strongly correlate with Aecon's experience and sustainability goals Strong Private Sector End Market Demand SUPPORTED BY NORTH AMERICAN UTILITY INVESTMENTS Contrecoeur Terminal PDB ос ELECTRIC UTILITY DISTRIBUTION Ontario Line - North Civil Elevated Guideway and Stations PDB ON = Yonge Subway Extension Fraser River Tunnel DBF ON 55% PDB BC Aging Electric Infrastructure Distribution infrastructure age relative to useful life GAS UTILITY DISTRIBUTION Aging Gas Infrastructure Gas Distribution Pipelines Constructed (By decade) Surrey Langley SkyTrain Guideway DBF BC Surrey Langley SkyTrain Stations DB BC 41% Within useful life ■Near end of useful life ■ At end of useful life 4% Annual capex related to electricity distribution to grow from US$50B in 2021 to $63B in 2025 in North America 44% ■Pre-1970s ■1980s ■1990s 2000s Nearly 45% of gas distribution infrastructure in North America is near or at the end of its useful life of 40 years Annual capex related to gas distribution to be in a range of US$26B to $28B from 2021 to 2025 in North America 16% 21% 19% Surrey Langley Skytrain Systems and Trackwork PDB BC TELECOMMUNICATIONS Capital Line South Extension (Phase 1) DB AB North American 5G Adoption Rate Percentage of Wireless Connections on 5G ENERGY TRANSITION U.S. Net Electricity Generation By Percentage Renewables are set to rise over time U.S. Virgin Islands Airport Modernization DBFOM 50% USVI 50% 40% 40% 30% 30% Providenciales International Airport (Turks & Calcos) DBFOM TCIS 20% 20% 10% 0% 10% 2019A 2020A 2021A 2022E 2023E 2024 2025E 2017A 2018A 2019A 2020A 2021A 2022A 2023E 2024E ACCON Supported by increasing fibre-to-the-home needs by all major North American carriers * It is possible that Aecon or joint ventures in which Aecon is a participant will not be successful in being awarded a contract for any or all of these major project pursuits. Full-list of pursuits not presented. ^ Source: Department of Energy, American Gas Association. Fortune Business Insights, BloombergNEF. Coal Nuclear Natural Gas Renewables 13#14Valuable Concessions and O&M Portfolio Bermuda L.F. Wade International Airport Passenger departures, billions per year maintenance concession to 2047 50.1% equity ownership and concession New terminal opened in December 2020 30-year operations and 22% 12 10 6 4 2 0 Global Air Passenger Departure Forecast 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 Passenger Level Forecast (December 2022) 2021 DFNI Americas Award for the Most Supportive Approach to Retail for Skyport* 2021 CCPPP Award for Innovations and Excellence in P3s & Historical Passenger Level 2021 Best Airport by Size and Region (under 2 million passengers per year in Latin America and Caribbean) # Canadian LRTS • 30-year maintenance concessions on Eglinton, Finch and Waterloo LRTS Availability-based payments with revenue risk mitigated by provincial transit counterparties Experienced team currently bidding on other Canadian transit projects GO On-Corridor Works 25-year operations & maintenance agreement in development for the GO Rail Expansion project in Ontario Decarbonization project involving electrification of system, new vehicle fleet and enhanced service Gordie Howe International Bridge • • 30-year operations and maintenance concession Availability-based payments with revenue risk mitigated by Canadian Federal Government Oneida Energy Storage Facility International Airport with exclusive rights to serve all commercial, private and cargo air traffic in Bermuda Majority of revenue generated through regulated, fixed fee mechanism, adjusted to inflation; downside protection via Minimum Revenue Guarantee Stable domestic and corporate travel base with less than 50% of traffic linked to tourism specifically • 20-year agreement with IESO (with additional 5 years of uncontracted revenue) for electricity storage services Availability-based payments for capacity services, as well as revenue from energy sold into Ontario electricity grid and operating reserve ^ Source: www.iata.org ACCON Skyport is responsible for the Bermuda L.F. Wade International Airport's operations, maintenance and commercial functions and is 50.1% owned by Aecon Concessions. & Canadian Council for Public-Private Partnerships (CCPPP) #Awarded by Airport Council International (ACI) World * CC&L Infrastructure acquired a 49.9% interest in the concessionaire, which closed in Q3 2023. Aecon Concessions retains the management contract for the airport and joint control of Skyport with a 50.1% retained interest. 14#15Concessions Experience in Infrastructure Development Proven capability to develop, construct, finance and operate diverse infrastructure concessions in Canada and internationally Solutions-based, experienced partner to international construction firms, governments and financial institutions Experienced in technology and systems integration in transit, tolling and airport infrastructure CAPABILITIES P3 PUBLIC PRIVATE PARTNERSHIPS STRATEGIC PARTNERING Provides for long-term cash flow opportunity with flexibility to monetize interests for future development projects Focused on decarbonization, energy transition and sustainability opportunities where prior Concessions experience can be leveraged PROJECT DEVELOPMENT PROJECT FINANCING ACCON GROWTH OPPORTUNITIES CANADIAN TRANSPORTATION & TRANSIT P3s RENEWABLE ENERGY/ ENERGY STORAGE UTILITIES INDIGENOUS PARTNERSHIPS OPERATIONS & MAINTENANCE INTERNATIONAL (AIRPORTS & OTHER) 15#16Q3 2023 Financial Results Q3 2022 TTM results include net benefit from the Canada Emergency Wage Subsidy ("CEWS") program of $4.1 million $ Millions (except per share amounts) Three Months Ended September 30 Twelve Months Ended September 2023 2022 Change+ 2023 2022 Change+ Revenue 1,240 1,321 6% 4,781 4,518 Gross Profit 45.7 118.6 61% 256.4 351.6 6% ▼ 27% Gross Profit Margin %& 3.7% 9.0% 530 bps 5.4% 7.8% Adjusted EBITDAⓇ 32.0 92.6 65% 140.7 213.0 240 bps 34% Adjusted EBITDA Margin %* 2.6% 7.0% 440 bps 2.9% 4.7% 180 bps Operating Profit 140.1 61.0 ▲ 130% 242.0 87.2 ▲ 178% Profit 133.4 34.5 ▲ 287% 171.9 22.8 654% Earnings per share - diluted 1.63 0.45 ▲ 262% 2.20 0.37 487% New Awards 591 991 40% 4,707 4,751 1% Backlog (at end of period)Ⓡ 6,202 6,275 1% 6,202 6,275 1% +bps = basis point This is a non-GAAP financial measure. Refer to page 2 in this presentation. *This is a non-GAAP financial ratio. Refer to page 2 in this presentation. ACCON & This is a supplementary financial measure. Refer to page 2 in this presentation. 16#17Financial Position, Liquidity and Capital Resources • • Balance Sheet ($M) Free Cash Flow ($M) September 30, 2023 Core Cash Bank Indebtedness Cash in Joint Operations 22.4 (30.0) Operating profit 2023 Q3 TTM 242.0 2022 Q3 TTM 87.2 410.0 Depreciation and amortization 88.3 92.3 Total Cash^ 402.4 (Gain) on sale of assets (228.0) (6.6) Income from projects accounted for using the equity (19.2) (16.4) Net Working Capital* Long-Term Debt - Finance Leases 380.6 method Equity Project EBITDAⓇ 57.6 56.6 Adjusted EBITDAⓇ 140.7 213.0 117.5 - Equipment & Other Asset Loans 24.6 Cash Interest Expense (net) (52.5) (45.4) LT Debt excluding Convertible Debentures" 142.1 Capital Expenditures (net of disposals) 40.9 (25.2) Income Taxes Paid (32.8) (32.8) Convertible Debentures (Face Value) due Dec. 2023 (5.0%) 184.0 Change in Working Capital (99.0) (176.1) Net JV Impact* (55.9) (54.2) Total LT Debt plus Convertible Debentures 326.1 Free Cash Flow™# (58.6) (120.7) LT Debt to Q3 2023 TTM Adjusted EBITDA&@+ - Excluding Convertible Debentures 1.0 x Cash Flow From Operations (87.6) (77.2) 2.3 x 23% - Including Convertible Debentures Debt to capitalization percentage On December 29, 2023, Aecon repaid the full principal amount of $184 million owed under its 5.0% unsecured convertible debentures, which were due on December 31, 2023, along with accrued unpaid interest Cash Flow From Investing Activities 334.0 (56.5) Cash Flow From Operations & Investing Activities 246.4 (133.7) No other debt or working capital credit facility maturities in 2023, except equipment and property loans and leases in the normal course Excludes restricted cash associated with Bermuda Airport Project. Excludes non-recourse project debt associated with Bermuda Airport Project. Long-term debt-to-Adjusted EBITDA ratio is a measurement that Management believes is commonly used by the investment community to assess the Company's debt leverage and liquidity. & Calculations based on face value of convertible debentures. * Net Working Capital is a capital management measure that management uses to analyze and evaluate Aecon's liquidity and its ability to generate cash to meet its short-term financial obligations. Management also believes this measure is commonly used by the investment community for valuation purposes. Refer to page 27 in this presentation for the composition of Net Working Capital and a quantitative reconciliation to the most comparable financial measure. "Debt to capitalization percentage is considered by the Company to be the most important metric in measuring the strength and flexibility of its consolidated balance sheets. Calculated as Debt of $324.9 million (including $182.7 million fair value of convertible debentures) divided by capitalization of $1,402.8 million, which is comprised of shareholders' equity of $1,077.9 million plus $182.7 convertible debentures and $142.2 million of debt, to equal 23%. * Net JV Impact represents the difference between Equity Project EBITDA included in Adjusted EBITDA (Equity Project EBITDA as defined in Aecon's Q3 2023 MD&A) and distributions from projects accounted for using the equity method. Excludes $317.6 million net proceeds on sale of ATE and minority sale of Bermuda Airport in Q3 2023 TTM and $30.4 million purchase amount (net of cash acquired) in Q3 2022 TTM, respectively, related to strategic business acquisitions since Q4 2021. # Free Cash Flow is a capital management measure that management uses to analyze and evaluate the cash generated after taking into consideration cash outflows that support its operations and maintain its capital assets. Management also believes this measure is commonly used by the investment community for valuation purposes. Refer to page 27 in this presentation for a quantitative reconciliation to the most comparable financial measure, being Cash Flow From Operations & Investing Activities. This is a non-GAAP financial measure or non-GAAP ratio. Refer to page 2 in this presentation. ACCON 17#18Outlook • • • Demand for Aecon's services across Canada continues to be strong. Aecon (including joint ventures in which Aecon is a participant) is prequalified on a number of project bids due to be awarded during the next twelve months and has a pipeline of opportunities to further add to backlog over time. With backlog of $6.2 billion at September 30, 2023 and recurring revenue programs continuing to see robust demand, Aecon believes it is positioned to achieve further revenue growth over the next few years. While volatile global and Canadian economic conditions are impacting inflation, interest rates, and overall supply chain efficiency, these factors have stabilized to some extent and have largely been and will continue to be reflected in the pricing and commercial terms of the Company's recent and prospective project awards and bids. However, certain ongoing joint venture projects that were bid some years ago have experienced impacts related, in part, to those factors, that will require satisfactory resolution of claims with the respective clients. Results have been negatively impacted by these four legacy projects in recent periods, undermining positive revenue and profitability trends in the balance of Aecon's business. Until these projects are complete and related claims have been resolved, there is a risk that this could also occur in future periods - see Section 5 "Recent Developments" and Section 10.2 "Contingencies" in the September 30, 2023 MD&A and Section 13 "Risk Factors" in the 2022 Annual MD&A regarding the risk on four large fixed price legacy projects entered into in 2018 or earlier by joint ventures in which Aecon is a participant. Subsequent to quarter end, on October 23, 2023 Aecon announced a strategic investment by Oaktree in Aecon Utilities. The investment subsequently closed on October 24, 2023. Oaktree acquired a minority ownership interest in Aecon Utilities by way of a net $150 million convertible preferred equity investment (the "Investment"). The Investment creates a vehicle to address attractive industry growth opportunities across utility end-markets in Canada and the U.S., provides financial flexibility to accelerate Aecon Utilities' acquisition strategy, introduces a recognized value-added partner in Oaktree with a successful track record in utilities infrastructure investing, and strengthens Aecon's consolidated balance sheet with Aecon receiving proceeds of $150 million from the Investment. This provides Aecon the financial flexibility to fund strategic growth initiatives. In addition to Aecon Utilities' new credit facility of $400 million, Aecon has a separate committed revolving credit facility of $450 million that replaces its prior $600 million facility. In the Construction segment, with strong demand, growing recurring revenue programs, and diverse backlog in hand, Aecon is focused on achieving solid execution on its projects and selectively adding to backlog through a disciplined bidding approach that supports long-term margin improvement in this segment. In addition to the selection of consortiums in which Aecon is a participant for two large transit related projects in 2022 noted above, in early 2023, a partnership in which Aecon is a participant announced that it had executed a six-year alliance agreement with Ontario Power Generation to deliver North America's first grid-scale Small Modular Reactor through the Darlington New Nuclear Project in Clarington, Ontario. In addition, Oneida LP, a consortium in which Aecon Concessions is an 8.35% equity partner, executed an agreement with the Independent Electricity System Operator for the Oneida Energy Storage Project to deliver a 250 megawatt / 1,000 megawatt-hour energy storage facility near Nanticoke Ontario, with Aecon awarded a $141 million Engineering, Procurement and Construction contract by Oneida LP. All of these projects further demonstrate Aecon's strategic focus in the industry with respect to projects linked to decarbonization, energy transition, and sustainability and represent more collaborative procurement models than have traditionally been used. In the Concessions segment, in addition to expecting an ongoing recovery in travel through the Bermuda International Airport through 2023, there are a number of opportunities to add to the existing portfolio of Canadian and international concessions in the next 12 to 24 months, including projects with private sector clients that support a collective focus on sustainability and the transition to a net-zero economy. The GO Expansion On-Corridor Works project and the Oneida Energy Storage project noted above are examples of the role Aecon's Concessions segment is playing in developing, operating and maintaining assets related to this transition. ACCON 18#19A Sustainability Aecon's sustainability strategy focuses on what we build and how we build it - we are building infrastructure projects that are helping drive the transition to a net zero future, while also expanding our expertise in sustainable construction practices. Environmental Leadership Sustainable Infrastructure Company of the Year (Canada by the North America Business Awards, 2022) First construction company in Canada to set a GHG target 2030 - 30% reduction in Direct CO2 Emissions on an Intensity Basis as compared to 2020 2050 - Net-Zero for Direct and Indirect CO2 Emissions Committed to the Government of Canada's Net-Zero Challenge & The Science Based Target Initiative Piloted the use of low carbon concrete & electric construction equipment Continue to adopt recognized environmental standards including the Envision framework Our People and Communities Canada's Best Employers (Forbes 2023) Best of the Best Award in the Green Building Culture Award category (Toronto Construction Association) Silver Certification in Progressive Aboriginal Relations (Canadian Council for Aboriginal Business) Partnerships to achieve goals Progressive Aboriginal Responsible Governance 2022 Sustainability Report - Building a Sustainable Future Oversight of sustainability was moved from the Risk Committee to the entire Board in 2022 Commitment to UN Sustainable Development Goals PARTNERSHIPS SILVER LEVEL AFFORDABLE AND RELATIONS CLEAN ENERGY 11 SUSTAINABLE CITIES AND COMMUNITIES INDUSTRY, INNOVATION AND INFRASTRUCTURE 17 FOR THE GOALS Canadian Council for Aboriginal Business Aecon Women In Trades (AWIT) Operating joint ventures with 2 First Nations in Alberta & 3 in Ontario Aecon's Reconciliation Action Plan Engaging in reconciliation by working in unison with Indigenous Peoples $200M+ in goods & services procured from the Indigenous economy in 2022 100% completion rating for Aecon's Code of Conduct ESG screening for preferred suppliers with a target of 100% completion rate by 2025 ACCON * Intensity based targets are based on economic output and represent tonnes of CO2 per million dollars of revenue. SUSTAINABLE DEVELOPMENT GOALS TCFD | TASK FORCE ED FINANCIAL DISCLOSURES 19#20Working Towards Net Zero Construction Today, the construction industry is responsible for about 10% of greenhouse gas emissions worldwide¹, and faces many opportunities for increased efficiency and lower emissions. Aecon is working to make construction activity more sustainable through innovative equipment, data-driven work processes and enhanced management of materials and waste. This is a summary of key initiatives we're using to reduce emissions and work towards net zero construction: NOTABLE SUSTAINABILITY INITIATIVES 14% direct, intensity-based reduction to date 30% direct, intensity-based reduction target 1 The 2020 Global Status Report for Buildings and Construction. 2 See 2021 Sustainability Report for some of our past initiatives. 2020 EV Charger Installations on Aecon Properties GeoExchange Installation 2022 2020 & 20212 VOLVO Low-Carbon Concrete Pilot Zero-Emission Wheel Loader Pilot Solar tracker Solar panels Solar-powered on trucks road signs Solar-powered light barrels Solar light tower BIO FUTURE CONSIDERATIONS Increase trials and use of low-carbon and zero-emission equipment Electric charging stations Continue to explore low-carbon construction materials COTRACT Battery-powered Lower-emissions tools vehicles Biodiesel Trialling of zero-emission Recycled asphalt Battery-powered generator Eco road salts equipment 2022 Alternative power for construction sites 2030 Net Zero scopes 1, 2 & 3 by 2050 wwwW 20 20 2050#21W ACCON AL Aeco APPENDIX#22Operating Profit & Adj. EBITDA Contribution By Segment Q3 2022 TTM results include net benefit from the Canada Emergency Wage Subsidy ("CEWS") program of $4.1M Operating Profit ($ Millions) Operating Profit Margin % Q3 2023 Q3 2022 % CHANGE Q3 2023 Q3 2022 BPS CHANGE Construction 1.3 63.4 98% Construction 0.1% 4.9% 480 Concessions 152.7 8.3 1740% Concessions nmf# nmf# nmf# TOTAL^ 140.1 61.0 130% TOTAL^ 11.3% 4.6% 670 Q3 2023 TTM Q3 2022 TTM Q3 2023 Q3 2022 % CHANGE TTM TTM BPS CHANGE Construction 53.5 116.1 54% Construction 1.1% 2.6% 150 Concessions 176.6 19.6 801% Concessions nmf# nmf# nmf# TOTAL 242.0 87.2 178% TOTAL^ 5.1% 1.9% 320 Adjusted EBITDA ($ Millions) @ * Adjusted EBITDA Margin % Q3 2023 Q3 2022 % CHANGE Q3 2023 Q3 2022 BPS CHANGE Construction 16.5 82.0 80% Construction 1.4% 6.3% 490 Concessions 27.4 20.7 32% Concessions nmf# nmf# nmf# TOTAL^ 32.0 92.6 65% TOTAL^ 2.6 7.0% 440 Q3 2023 Q3 2022 Q3 2023 Q3 2022 TTM TTM % CHANGE TTM TTM BPS CHANGE Construction 91.9 192.1 52% Construction 2.0% 4.3% 230 Concessions 89.3 67.8 32% Concessions nmf# nmf# nmf# TOTAL^ 140.7 213.0 34% TOTAL^ 2.9% 4.7% 180 ^ After corporate costs and eliminations. # Not Meaningful. ACCON This is a non-GAAP financial measure. Refer to page 2 in this presentation. *This is a non-GAAP ratio. Refer to page 2 in this presentation. 22 22#23Construction Q3 2023 Results Revenue down by $83M, or 6%, quarter-over-quarter Q3 2023* Revenue ($M) Q3 2023 TTM* Revenue ($M) $4,692 $4,448 -6% +5% $1,299 $1,215 $106M in civil operations driven primarily by a lower volume of roadbuilding construction work in eastern Canada of $127 million as a result of the sale of ATE in the second quarter of 2023, and partially offset by an increase in major projects work in western Canada. $11M in nuclear operations from a lower volume of refurbishment work at nuclear generating stations located in Ontario. $2M in utilities operations. $30M in industrial operations driven primarily by increased activity on mainline pipeline work which offset a lower volume of field construction work primarily at chemical facilities in eastern Canada. Q3 2022 Q3 2023 Q3 2022 TTM Q3 2023 TTM $6M in urban transportation solutions primarily from an increase in rail expansion and electrification work in Ontario. New Awards ($M) New Awards ($M) $4,663 $4,612 $966 -42% -1% New awards lower by $403M, or 42%, quarter-over-quarter $563 ACCON Totals and variances may not add due to rounding and eliminations. Q3 2022 Q3 2023 Q3 2022 TTM Q3 2023 TTM 23#24Construction Q3 2023 Results (continued) Q3 2022 TTM results include net benefit from the Canada Emergency Wage Subsidy ("CEWS") program of $4.1M Q3 2023* Adjusted EBITDAⓇ down by $65M, or 80%, quarter-over-quarter and Operating Profit down by $62M, or 98%, quarter-over-quarter Lower gross profit in civil operations due to negative gross profit of $41.6 million in the third quarter of 2023 from one of the four fixed price legacy projects versus a gross profit of $1.0 million in the same period in 2022 from the same project.+ Negative gross profit of $49.5 million from one of the four fixed price legacy projects in urban transportation solutions compared to a negative gross profit of $22.5 million in the same period last year from the same project.+ ACCON * Totals and variances may not add due to rounding. This is a non-GAAP financial measure. Refer to page 2 in this presentation. See Section 5 "Recent Developments" and Section 10.2 "Contingencies" in the Q3 2023 MD&A and Section 13 "Risk Factors" in the 2022 Annual MD&A. Q3 2023 TTM* Adj. EBITDA ($M) Adj. EBITDA ($M) -80% -52% $82 $192 $92 $17 Q3 2022 (6.3% margin) Q3 2023 (1.4% margin) Q3 2022 TTM Q3 2023 TTM (4.3% margin) (2.0% margin) Operating Profit ($M) Operating Profit ($M) $116 $63 -98% -54% $54 $1 Q3 2022 TTM Q3 2023 TTM Q3 2022 (4.9% margin) Q3 2023 (0.1% margin) (2.6% margin) (1.1% margin) 24#25Concessions Q3 2023 Results Revenue up by $4M, or 21%, quarter-over-quarter Primarily due to an increase in commercial flight operations at the Bermuda International Airport. Adjusted EBITDAⓇ up by $6M, or 32%, quarter-over-quarter and Operating Profit up by $144M, or 1,740%, quarter-over-quarter Q3 2023* Revenue ($M) Q3 2023 TTM* Revenue ($M) $74 +23% $26 $22 +21% $91 Q3 2022 Adj. EBITDA ($M) Q3 2023 Q3 2022 TTM Q3 2023 TTM Adj. EBITDA ($M) $89 $27 $68 +32% $21 +32% Q3 2023 Q3 2022 TTM Q3 2023 TTM Operating Profit ($M) Operating Profit ($M) Primarily driven by a gain related to the sale of a 49.9% interest in Skyport of $139.0 million, including a fair value remeasurement gain of $80.4 million on Aecon's 50.1% retained interest in Skyport, an improvement in operating results at the Bermuda International Airport, and from an increase in management and development fees. Q3 2022 ACCON Totals and variances may not add due to rounding and eliminations. This is a non-GAAP financial measure. Refer to Refer to page 2 in this presentation. $177 +801% $152.7 +1,740% $8.3 $20 Q3 2022 Q3 2023 Q3 2022 TTM Q3 2023 TTM 25#26Q3 2023 Financial Results Excluding Legacy Projects, Property Sales and Business Dispositions $ Millions Three Months Ended September 30 Twelve Months Ended September 30 2023 2022 Change+ 2023 2022 Revenue 1,240 1,321 6% 4,781 4,518 Change+ 6% Legacy Projects (176) (199) (785) (754) ATE Results Pre-Sale (126) (150) (296) Pro Forma Revenue 1,064 995 7% 3,845 3,468 A 11% Operating Profit Legacy Projects Loss / (Profit) Property Dispositions (Gain on Sale) ATE Results Pre-Sale Loss/ (Profit) ATE Disposition Loss / (Gain on Sale)^ Skyport Minority Sale (Gain on Sale) Pro Forma Operating Profit Adjusted EBITDAⓇ Adjusted EBITDA Margin %* Legacy Projects Loss / (Profit) ATE Results Pre-Sale Loss / (Profit) Pro Forma Adjusted EBITDA Pro Forma Adjusted EBITDA Margin %* 140.1 61.0 ▲ 130% 242.0 87.2 ▲ 178% 91.1 30.2 234.2 105.2 (43.4) (10.2) 1.5 5.5 (36.5) (6.4) (139.0) (139.0) 93.7 81.0 16% 262.8 186.0 41% 32.0 92.6 65% 140.8 213.0 34% 2.6% 7.0% 440 bps 2.9% 4.7% 180 bps 91.1 30.2 234.2 105.2 (14.8) (3.8) (22.9) 123.1 108.0 14% 371.2 295.4 26% 11.6% 10.9% ▲ 70 bps 9.7% 8.5% 120 bps * 100% sale of Aecon Transportation East Business ("ATE") to Green Infrastructure Partners Inc. ("GIP"), which closed in Q2 2023 (May 1, 2023). * CC&L Infrastructure acquired a 49.9% interest in the concessionaire, which closed in Q3 2023 (September 20, 2023). Aecon Concessions retains the management contract for the airport and joint control of Skyport with a 50.1% retained interest. +bps basis point ACCON This is a non-GAAP financial measure. Refer to page 2 in this presentation. *This is a non-GAAP financial ratio. Refer to page 2 in this presentation. 26#27Non-GAAP Measures Quantitative Reconciliation * * Net Working Capital Reconciliation ($M) Free Cash Flow Reconciliation ($M) Cash Flow From Operations & Investing Reconciliation ($M) September 30, 2023 Q3 2023 TTM Q3 2022 TTM Q3 2023 Q3 2022 TTM TTM Trade and Other Receivables 1,042.5 Unbilled Revenue Inventories 759.4 29.7 Profit Before Income Taxes 183.0 36.2 Free Cash Flow (58.6) (120.7) Finance cost 66.6 52.0 Finance income (7.5) (1.1) Defined benefit pension 0.6 (0.4) Prepaid Expenses 100.6 Operating Profit 242.0 87.2 Stock-based compensation settlements and receipts (3.8) (3.0) Less Depreciation and amortization 88.3 92.3 Concession deferred revenue (4.0) (3.8) Gain on sale of assets (228.0) (6.6) Unrealized foreign exchange (gain) / loss (4.1) 3.0 Trade and Other Payables 1,178.3 Income from projects accounted for using the equity method Increase (decrease) in provisions 3.3 4.9 (19.2) (16.4) Provisions 19.0 Stock-based compensation expense 22.0 20.0 @ Equity Project EBITDA Deferred Revenue 354.4 Adjusted EBITDA 57.6 140.7 56.6 Decrease (increase) in restricted cash balances (11.1) (2.4) 213.0 Investment in concession rights 0.1 Net Working Capital 380.5 Cash interest paid (60.0) (46.4) Increase in long-term financial assets (15.0) (0.1) Cash interest received Purchase of property, plant and equipment Proceeds on sale of property, plant and equipment 7.5 (22.6) 74.1 1.0 Proceeds on sale of a subsidiary, net of cash on hand 317.6 (32.2) 10.4 Net cash outflow on acquisition of a business Other (30.4) (0.4) (0.8) Equity Project EBITDA Reconciliation ($M) Increase in intangible assets (10.6) (3.5) Total Reconciling Items 305.0 (13.0) Income taxes paid (32.8) (32.8) 03 2023 TTM 03 2022 TTM Free Cash Flow before Working Capital and net JV Impact Change in other balances related to operations Equity Project EBITDA 96.3 109.6 Cash Flow from Operations (87.6) (77.2) (99.0) (176.1) Cash Flow from Investing Activities 334.0 (56.5) (57.6) (56.6) Cash Flow from Operations and Investing Activities 246.4 (133.7) Operating profit of projects accounted Distributions from projects accounted for using the equity method 1.7 2.4 57.1 55.8 for using the equity method Free Cash Flow (58.6) (120.7) Depreciation and amortization of projects accounted for using the 0.5 0.8 equity method Equity Project EBITDA 57.6 56.6 ACCON This is a non-GAAP financial measure. Refer to page 2 in this presentation. * Totals may not add due to rounding. 27#28Capital Markets Overview ARE.TSX Statistics as of January 4, 2024 Analyst Coverage^ Firm ATB Capital Analyst Telephone Chris Murray (647) 776-8246 BMO Capital Markets Devin Dodge $13.44 Share Price 5.5% (416) 359-6774 Dividend Yield 61.8 Million Shares Outstanding 0.4 Million ($5.0 Million) Avg. Daily Share Volume (3 months TSX & ATS) - | 52 Week Low/High ~$0.8 Billion Market Capitalization $8.29 / $14.04 Canaccord Genuity CIBC Capital Markets Desjardins Securities National Bank Financial Paradigm Capital Raymond James Jacob Bout Yuri Lynk (514) 844-3708 (416) 956-6766 Benoit Poirier (514) 281-8653 Laurentian Bank Securities Jonathan Lamers (416) 577-1755 Maxim Sytchev (416) 869-6517 Alexandra Ricci (416) 361-6056 Frederic Bastien (604) 659-8232 $0.70 $0.74 $0.74 RBC Dominion Securities Sabahat Khan (416) 842-7880 $0.64 $0.58 $0.46 $0.50 $0.50 Stifel GMP Ian Gillies (416) 943-6108 $0.40 $0.36 $0.32 TD Securities Michael Tupholme (416) 307-9389 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 Expected ACCON Annual Dividend History 6 Buy/Outperform Recommendations 6 Hold / Sector Perform Recommendations $13.08 Average Target Price The views of analysts do not necessarily represent the views of Aecon. 28#29ACCON aecon.com in f O ADAM BORGATTI Senior Vice President Corporate Development & Investor Relations [email protected] STEVEN HONG Director Corporate Development & Investor Relations [email protected] INVESTOR RELATIONS 416.297.2600] [email protected] VANCOUVER 1055 Dunsmuir Street, Suite 2124 Vancouver, BC V7X 1G4 CALGARY 28 Quarry Park Blvd SE, Suite 310 Calgary, AB T2C 5P9 TORONTO 20 Carlson Court, Suite 105 Toronto, ON M9W 7K6 MONTREAL 2015 Peel Street, Suite 600 Montreal, QC H3A 1T8 ACCON IR Award winner Canada 2023 magazine