Sterling Infrastructure : 2024 Sustainability Report

For Better and Beyond

THE STERLING WAY -- 2024 SUSTAINABILITY REPORT

Corporate	Safety	People	Planet	Appendix
Introduction Governance

INTRODUCTION

04 About Sterling

05 Awards and Industry Recognition

07 Messages from Our Leaders

1. The Sterling Way
2. Deepening Our Commitment
3. Forging a Sustainable Future

	CORPORATE		SAFETY
	GOVERNANCE
	21	It All Starts with Safety
16	A Foundation of Integrity
22	Employee Protection
		and Transparency
17	Ethics and Compliance			and Safety Guidance
23	Innovation and
18	Risk Management
		Improvement

19 Protecting Data. Reducing Risk.

	PEOPLE		PLANET		APPENDIX
25	People, Our Most	33	Protecting Our	40	About This Report
		Precious Resource			Environment	41	Sterling Internal and
26		34
A Holistic Approach to	Applying Technology			External Stakeholders
		Employee Health and			To Reduce Environmental	42	Our Actions and Initiatives
		Wellness			Impacts
27	Developing Future Leaders	35	Sustainable Investments	43	SASB Framework:
28		36				Engineering and
Supporting Our	Climate-Related Projects			Construction Services
		Communities	37	Measures To Protect	44	TCFD Recommended
31
Investing in Future			the Environment			Disclosures
		Generations	38	Community Partners	45	Sustainability Reporting
					and Good Neighbors			Roadmap

This report provides Environmental, Social and Governance (ESG) information to stakeholders. Report release date: 3/19/2024 reflects activity beginning in 2020. We intend to provide annual updates to this report and periodic updates on our website, strlco.com. The data in this report are unaudited.

Cover image: Houston Spaceport rendering

The Sterling Way - 2024 Sustainability Report 2

Introduction	Corporate	Safety	People	Planet	Appendix
Governance

Introduction

In This Section

04 About Sterling

1. Awards and Industry Recognition

1. Messages from Our Leaders

1. The Sterling Way
2. Deepening Our Commitment
3. Forging a Sustainable Future

Road and Highway Builders (Transportation Solutions) project site

The Sterling Way - 2024 Sustainability Report 3

Introduction	Corporate	Safety	People	Planet	Appendix
Governance

About Sterling

Sterling Infrastructure, Inc. ("Sterling," "the Company," "we," "our" or "us"), a Delaware corporation, operates through a variety of subsidiaries within three segments specializing in E-Infrastructure, Transportation and Building Solutions in the United States, primarily across the Southern, Northeastern, Mid-Atlantic and Rocky Mountain regions and the Pacific Islands.

E-Infrastructure Solutions provides advanced, large-scalesite development services for manufacturing, data centers, e-commercedistribution centers, warehousing, power generation and more.

Transportation Solutions includes infrastructure and rehabilitation projects for highways, roads, bridges, airports, ports, rail and storm drainage systems.

Building Solutions projects include residential and commercial concrete foundations for single- family and multi-familyhomes, parking structures, elevated slabs, other concrete work and residential plumbing services.

From strategy to operations, we are committed to sustainability

by operating responsibly to safeguard and improve society's quality of life. Caring for our people and our communities, our customers and our investors - that is The Sterling Way.

"We build and service the infrastructure that enables our economy to run, our people to move and our country to grow."

- Joe Cutillo, CEO

For more information about Sterling, visit our website at strlco.com.

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Introduction	Corporate	Safety	People	Planet	Appendix
Governance

Awards and Industry Recognition

Sterling Corporate

2023 ENR Lists
	#29			#51
		Top 50			Top 400
		Domestic Heavy
				Contractors
		Contractors

	#80
	#161
	Top 100			Top 250
	Contractors by			Global
	New Contracts			Contractors

Forbes 2024

#15

Most Successful

Mid-Cap

Companies

Baron's 2023

Roundtable

Stock Pick

Project Awards

Banicki Construction, Inc.

• 2023 AGC of AZ Build Arizona Project of the Year - Terminal 4 South Concourse 1 Apron
• 2023 AZ MDCE (Million Dollar Circle of Excellence) Award

Ralph L. Wadsworth Construction Company, LLC

+ 2023 Construction Risk Partners Build America

Award, Highway & Transportation Renovation

$100+ Million

+ 2023 Utah Construction and Design, Most

Outstanding Highway Over $10 Million

+ 2023 AGC of Utah, Overall Highway/Utility/

Transportation Project of the Year

+ 2023 AGC of Utah, Urban Highway Project

of the Year

+ 2023 AGC of Utah, Active Transportation Project

2023 American Marketing Association Crystal Awards Finalist

• Corporate Identity: Sterling Brand Identity
• The Sterling Brand Identity Guide
• Social Responsibility Program:
  2023 Sustainability Report "Building a Better Tomorrow - The Sterling Way"

This page lists some of the most recent Awards Sterling and Sterling Subsidiaries have received.

• Engineering News-Record (ENR)
• Forbes 2024 America's Most Successful Mid-Cap Companies annual list
• Associated General Contractors of America (AGC)
• American Council of Engineering Companies (ACEC)
• 2023 American Marketing Association Houston Chapter

of the Year Award

+ 2023 ACEC Grand Award in Transportation

+ 2023 AGC Transportation Project of the Year

+ 2023 Highway Project of the Year, Utah

Construction and Design

+ 2023 Highway Project of the Year Over $10 Million,

Utah Construction and Design

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Introduction	Corporate	Safety	People	Planet	Appendix
Governance

Awards and Industry Recognition

Safety Awards

E-Infrastructure Solutions

Plateau

+ Rising Star for Safety October 2023

Petillo

• UTCA Construction Safety Award for Outstanding Achievement in Construction Safety and Health 2022
• Health ACC NJ Annual Safety Award for Outstanding Safety Record for the Year 2022 - Lost Workday Incidence Rate Below the National Average

Transportation Solutions

RLW

• UTAH Safety Council: 2023 Award of Merit - Field of Safety as Measured by Outstanding Safety Performance
• UTAH Safety Council: 2023 Million Hours Award -
  in Recognition of Completing 1,000,000 Consecutive Work Hours Without an OSHA Recordable Injury, Illness, Days Away from Work or Death
• UTAH Safety Council: 2023 Perfect Record Award - in Recognition of Completing 12 Consecutive Months Without an OSHA Recordable Injury, Illness, Days Away from Work or Death
• 2023 ARTBA Contractor Safety Award
• American General Contractors of UTAH: Achievement of Safety Excellence - Over 1 Million Man Hours Worked - Diamond Award Winner 2022
• AGC The Construction Association: Certificate of
  Commendation for Excellent Safety Record 2022 - Zero Incident Rate Highway - 425,000 and up Work Hours
• AGC The Construction Association: Certificate of
  Commendation for Excellent Safety Record 2022 - Zero Incident Rate Building - 275,000 and up Work Hours
• Colorado Contractors Association: Zero Incidence Rate - Exemplary Accident Prevention Record &
  12 Months Without a Lost Time Injury or Illness 2021

Banicki Construction, Inc.

• 2023 Arizona AGC Safety Professional of the Year
• 2023 ARTBA Contractor Safety Award

Texas Sterling Construction

• 2023 ARTBA Contractor Safety Award
• 2023 AGC of Texas Blue Bonnet Award
• 2023 AGC National Safety Award

Banicki Safety Manager

Awarded Safety Professional

of the Year

It was an honor to be named the 2024 Safety Professional of the Year by the Arizona Chapter of the Associated General Contractors (AGC). This award represents Banicki and Sterling's unwavering commitment to holding safety as the paramount pillar throughout all of our projects.

We have built a strong safety culture at Banicki that extends beyond work and into our employees' homes by including their children and grandchildren in our yearly safety calendar contest. Combined with Sterling's drive to focus best safety practices on leading indicators, I truly believe Sterling and our companies have one of the strongest safety programs in the nation.

I consider myself lucky to work for a company that puts safety first in everything that we do. This award is a testament to our collective dedication and commitment to maintaining a safe and sound work environment.

• Marc Momcilovich, CSP, CHST Safety Manager, J Banicki Construction

This page lists some of the most recent safety awards Sterling Subsidiaries have received.

• Utility & Transportation Contractors Association (UTCA)
• Associated Construction Contractors of NJ (ACC NJ)
• American Road & Transportation Builders Association (ARTBA)

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Introduction	Corporate	Safety	People	Planet	Appendix
Governance

Our dedication to sustainability is stronger than ever.

A Message from Our Chief Executive Officer, Joe Cutillo

Sterling is playing a critical role in the resurgence of manufacturing production in the United States. From the data infrastructure that enables AI and other emerging technologies, and the highways, bridges and airports that connect us, to the homes we live in, this infrastructure is the foundation of the America of tomorrow.

We embrace our responsibility to build a cleaner, better, and more equitable future. We believe that good business practices and sustainable business practices are inextricable and enable us to deliver meaningful and lasting value for our stakeholders. In 2023, we proudly joined thousands of other companies committed to responsible business actions that safeguard our future by signing the UN Global Compact. To our shareholders, we delivered another year of record results, with revenue growth of 11%, adjusted EBITDA growth of 24%, and adjusted diluted EPS growth of 40%. We believe there is continued opportunity for growth and margin expansion within each of our segments, supported by our record backlog at year-end. We are extremely excited about the opportunities ahead.

We are very proud of our teams.

Joe proudly serves on the Board of the American Road & Transportation Builders Association (ARTBA)

This year's report showcases our company-wide efforts to build a better future. Through engagement in sustainability-focused partnerships, our people are implementing real change that goes beyond our corporation. We are testing next-generation heavy equipment for the largest yellow iron suppliers. This allows us early access to some of the most fuel-efficient equipment on the market. We are also helping our partners improve their next-generation machines. Further, we continuously explore new technologies that offset and reduce our carbon footprint and invest in fuel additives that enhance efficiency and reduce emissions across our fleet. These are just a few examples, and there is still much more to be done. For 2024 and beyond, we remain committed to adopting even more responsible practices and incorporating new and innovative sustainable solutions across Sterling. We remain steadfast in caring for our people, our customers, our investors, our communities and the environment. That is The Sterling Way.

Joe Cutillo, CEO

By remaining focused on and committed to our strategic vision and	+ Revenue growth of 11%
ever-increasing sustainability efforts, we are solidifying our base,	At Sterling, we build and service the infrastructure that enables our economy to run,
+ Adjusted EBITDA and EPS growth 40%
growing in new markets and delivering more value to our customers	our people to move and our country to grow.
+ Backlog growth at year end 46%
than ever before.

The Full Year 2023 financial information is from continuing operations and comparisons are to the prior year. For more information about Sterling Financial Results, including Adjusted EBITDA and Adjusted EPS Reconciliations, visit our website at strlco.com.

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Introduction	Corporate	Safety	People	Planet	Appendix
Governance

Due Diligence That Makes a Difference

As Chief Financial Officer, my responsibilities include helping guide our company through the ever-more complex sustainability disclosure and regulatory environments to deliver reliable and transparent ESG reporting. We strive to continue planning and preparing for the expected disclosure requirements. Additionally, I monitor and analyze how climate change scenarios could impact our business and financial performance.

At Sterling, we recognize the value of exploring opportunities for growth through sustainable service offerings and solutions.

We are always looking ahead to the long-term considerations that stem from climate-related risks and opportunities to not only help us achieve a sustainable future and a positive impact on society, but also create new areas of growth for the company. Furthermore, we promote and

foster coordination between corporate functions because, from financial expertise and strategic

decision-making to risk and stakeholder management, strategic alignment is key to ensure success in all of Sterling's sustainability endeavors.

Ronald A. Ballschmiede, Executive Vice President,

Chief Financial Officer & Chief Accounting Officer

• We continue to pursue strategic investments in projects or businesses that meet our operational goals and overall profitability.
• Our capital equipment investments support changing levels of production activities and replace retiring equipment.
• 2024 capital expenditures are expected to be in the range of $55 to $60 million; however, the award of a project requiring significant purchases of equipment or other factors could result in increased expenditures.

Ronald currently serves or has served as a Board member of The Woodlands Texas Children's Hospital Advisory Council, the Board of Executive Advisors for Northern Illinois University College of Business and the Chicago Better Business Bureau.

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Governance

Excellence Guided by Governance

As sustainability, governance and the regulatory environment in which we operate continue to evolve, we are not only focusing on the issues of today, but we are also anticipating what could be important and impactful for our industry in years to come. My role as Chief Compliance Officer requires me to be proactive, engaged and informed in order to offer a broader perspective to this dynamic landscape.

In addition to our strategic endeavors, my top priority

is determining what is most valuable to our shareholders and stakeholders.

This includes looking for ways to better integrate human rights and engage with stakeholders. We believe in the critical foundation that our Governance and Compliance program provides to our organizational sustainability efforts. It's why our sustainability report begins with the Governance section.

We do this to ensure our corporate social responsibility actions align with our Company's strategy.

Mark D. Wolf, General Counsel,	Mark is a proud member of the
Texas General Counsel Forum.
Chief Compliance Officer & Corporate Secretary

• Sterling is committed to strong and effective governance practices that promote and protect the interests of our shareholders and extends to all stakeholders.
• In connection to our commitment to strong governance practices that we believe deliver value to our shareholders, the corporate governance and nominating committee of the Board hired a third-party consultant in April 2023 to assist in evaluating the experience, qualifications, attributes and skills of the members of the Board.

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Introduction	Corporate	Safety	People	Planet	Appendix
Governance

Driving Dialogue. Delivering Value.

At Sterling, we are dedicated to fostering strong, long-term relationships with our investors and the broader stakeholder community. We believe that open and constructive communication is essential to our shared success and take great pride in building trust through transparency and honesty.

As part of my role, I am committed to engaging with the investment community in a transparent and responsive manner. This includes highlighting our increasing focus on sustainability and responsible corporate practices.

Throughout the year, we engage with our investors through calls, meetings, conferences, and industry events. These engagements not only provide us with an opportunity to share Sterling's best practices and efforts to build a better, safer, cleaner and more equitable tomorrow but also allow us to gain valuable insight into shareholder priorities related to sustainability. We find that our shareholders often have excellent recommendations of ways that we can enhance our efforts.

Leveraging our work across the ESG landscape encourages meaningful shareholder and stakeholder engagement. More importantly, it sparks innovation, propels growth and positions Sterling at the forefront of sustainability and responsibility in our industry.

Noelle Dilts, CFA

VP of Investor Relations and Corporate Strategy

• STRL shares increased 168% versus a 25% increase in the S&P 500.
• We believe that building trust through transparency is a critical element of long-term success.
• Leveraging our work across the sustainability landscape encourages meaningful shareholder and stakeholder engagement and helps to create a cycle of continuous improvement.

Noelle is a member of the National Investor Relations Institute (NIRI) Denver and Houston Chapters.

Sterling and S&P 500 price performance 12/30/2022 to 12/29/2023. For more information about Sterling's Investor Relations, visit our website at strlco.com.

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