STOBG SRR Report 2026_FINAL_022326

STOBG Cares

Corporate RESPONSIBILITY REPORT / 2026

Table of Contents INtroduction 01 Who We Are 02 Advancing Sustainability 03 People & Culture 04 Our Culture of Safety 05 Community Impact 06 Ethical Business Practices/Governance 07 Appendix & Additional Resources

Together, We Build The Extraordinary.

At STO Building Group, our commitment to building responsibly is the foundation of who we are and how we operate. As we present our 2026 Corporate Responsibility Report, we are proud to share the progress we have made, the lessons we have learned, and the aspirations that continue to drive us forward.

This year’s report reflects the collective efforts of our 5,700+ employees across North America and Europe, each of whom plays a vital role in shaping our culture and delivering on our promise to clients, partners, and communities.

We are proud of how we’re helping our industry advance, from expanding efforts to reduce carbon emissions to pioneering new approaches to waste reduction and material circularity. These actions are not just about compliance—they are about leadership, accountability, and our responsibility to future generations.

And whether it’s our approach to construction or to community service, our teams consistently demonstrate that meaningful change starts with showing up and giving back. Our success is measured

not only by the buildings we deliver, but by the positive difference we make in our communities.

As you read this report, we invite you to explore the stories, achievements, and aspirations that define STO Building Group. Together, we are building a more sustainable, inclusive, and resilient future.

Building together James K. Donaghy Executive Chairman

Robert Mullen CEO

SUMMARY

EXECUITIVE

At STO Building Group (STOBG), success is measured not just by the buildings we create but by the impact we have on our people, communities, and the environment. Our commitment to corporate responsibility is woven into our culture and business practices, ensuring we build a sustainable and responsible future. Our 2026 Corporate Responsibility Report presents a comprehensive overview of that commitment, organized around the key themes that reflect our values and strategic priorities.

We start with our commitment to fostering sustainability in the construction industry. We have advanced our environmental policies, expanded our efforts to reduce carbon emissions, and pioneered new approaches to waste reduction and circularity in construction materials. Our teams are leading the way in mass timber construction, piloting innovative recycling programs, and leveraging digital tools to track and improve our environmental performance in real time. These actions are not just about compliance—they are about leadership, accountability, and our responsibility to future generations.

Our people and culture as an organization centers around the 5,700+ professionals who make up the STOBG team across North America and Europe. We continue to invest in their well-being, growth, and safety through programs like Thrive 360° and a range of professional development and mentorship initiatives. Diversity, equity, and inclusion are embedded in our culture, and we are proud to foster an environment where every employee can thrive and contribute meaningfully. The health and safety of that team and our client and partner community is just as important; in fact, our Safety 360° approach has not only

improved our safety statistics but also created a culture of caring for those around us unparalleled in construction.

Community impact is another cornerstone of our identity.

Whether it’s volunteering, fundraising, or supporting local organizations, our teams consistently demonstrate that meaningful change starts with showing up and giving back. Our success is measured not only by the buildings we deliver, but by the positive difference we make in our communities.

Finally, our commitment to ethical business practices and strong governance ensures that we operate with integrity, transparency, and accountability. We hold ourselves and our partners to the highest standards, continuously improving our processes and policies to meet the evolving needs of our stakeholders.

This report showcases STO Building Group’s holistic approach to corporate responsibility, integrating sustainable building practices, a people-first culture, rigorous safety standards, community engagement, and ethical governance. These themes collectively drive our mission to build responsibly and create lasting value for clients, employees, and communities.

01

Who We Are

O N E C O M PA N Y, U N I T I N G A FA M I LY O F B U I L D E R S Imagine if a team of the world’s top contractors agreed to come together, pool their expertise and resources, and take on your challenges, no matter how big or small?

Top 5

largest privately held/employee-owned commercial building company

5,700+ 50+ diverse group of staff worldwide

offices across the US, Canada, UK, Ireland, and the Netherlands

80%

.53

$5B

$15.2B

The possibilities would be endless.

Welcome to STO Building Group: a privately-owned family of toptier builders who operate collaboratively, innovate uniquely, and join powerfully to put you first.

Unlike any construction company in the industry, each of our builders is empowered to stay true to their distinct business model and heritage, while sharing coveted construction resources— like real-time data, lessons learned, trade relationships, bonding, and buying power.

That means our clients get the best of both worlds—the personalized experience of local experts, supported by an unrivaled network of global problem solvers.

business from repeat clients

in bonding capacity

EMR well below national average of 1.00

in annual construction volume

02

Advancing Sustainability

OUR ENVIRONMENTAL POLICY

1

We’re committed to managing our environmental impact as an integral part of our operations. We are taking sustainable measures like the following across our organization and industry:

Carbon Reduction

Our organization intends to explore the measurement and analysis of emissions from our operations. We aim to cooperate with clients in exploring potential solutions for GHG (Greenhouse Gas) reductions, focusing on efficiency improvements, such as reducing fuel usage and considering electrification as a preferred option.

7

Biodiversity

We will help raise awareness around biodiversity, mitigation, and adaptation principles with our industry partners and take action, where appropriate.

This will be demonstrated through commitments, efforts, and achievements.

2

3

Our efforts include managing waste generation in our operations and business activities. We strive to increase diversion and reuse, promoting the responsible management of waste and recycling as integral steps in our circularity journey.

Projects will adhere to applicable EPA (and/or local authority) standards for preventing pollution through our construction activities.

Such measures are often found in our site-specific safety manuals in the Environmental Protection section. We will endeavor to address pollution from our operations by promoting the use of ecofriendly technologies, processes, and materials.

Waste Reduction

8

Client Health & Safety

We require our visitors to comply with health and safety regulations applicable to STOBG employees and the governing STOBG location, as set out in our site-specific safety manuals and STOBG’s Visitor Policy.

Pollution Prevention

9

Environmental Laws & Regulations

We will endeavor to understand and comply with environmental laws, regulations, and standards applicable to our operations, as well as any other requirements that we may agree to with our clients or stakeholders.

4

Energy, Water & Resource Conservation

We will explore adoption of energy and water efficiencies as new technologies become available. Through our projects, we will seek to work with our clients and partners to plan for responsible resource use and to offer suggestions that enhance energy, water, and resource conservation.

10

Human Rights

Everyone is entitled to fundamental human rights and dignity, regardless of their race, ethnicity, gender, religion, sexual orientation, or any other personal characteristic.

We are committed to upholding these rights, and we recognize that this responsibility extends beyond the workplace and into the broader community. Our Human Rights Policy endeavors to protect human rights, to create a more just and equitable world for all.

5

6

Through our Safety 360⁰ program, we focus on indoor air quality, hydration, nutrition, and the mental health of our employees and business partners.

We strive to engage and inspire our employees, clients, and partners to make positive impacts on the environment and educate our staff to make them aware of the environmental impacts of their work and how to manage them where possible. We will work to be an environmentally responsible neighbor and act to correct conditions within our control that may endanger health, safety, or the environment.

Wellness

11

Speaking Up

We promote an atmosphere in which employees feel safe to engage in open and honest communication. Any employee who wishes to report a concern about potential or actual environmental impacts of our operations, or inappropriate, unethical, or illegal conduct, can contact one of several company resources.

Leadership

As a leader in the construction industry, we will evaluate our environmental performance and identify areas for improvement.

We Build Green

Our project teams are combining proven strategies with cutting-edge innovation to reduce the environmental footprint of the construction process and the buildings we deliver.

Here are just a few examples.

Photography © Brad Feinknopf

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MITHUN PIER 56 OFFICE, SEATTLE 15 GEORGE’S QUAY/AON, DUBLIN, SOMA (25 WATER STREET), NYC IRELAND At historic Pier 56, Abbott Pavarini McGovern spearheaded the

VAGELOS LABORATORY FOR ENERGY SCIENCE & TECHNOLOGY, PHILADELPHIA

PROJECT MASTODON, FORT WAYNE

Construction delivered tenant improvements for Mithun’s corporate headquarters. Achieving the Living Building Challenge (LBC) Petal Certification in Materials, Beauty, and Equity, the renovation prioritized ethically sourced materials, equitydriven design, and visual harmony.

Facing supply chain disruptions and long lead times, the team worked with Integrated Eco Strategy and leveraged digital tools like “Red2Green” to ensure all specified products met the rigorous LBC standards. Reclaimed timber, detailed waste diversion reporting, and an intentional procurement strategy made this project a benchmark in sustainable workplace fit-outs.

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Structure Tone Dublin set a new standard for sustainable construction in Ireland by delivering the country’s two highest-scoring LEED Platinum projects: 15 George’s Quay (BD+C: C&S) and Aon’s headquarters (ID+C: CI). These landmark achievements reflect their commitment to driving environmental performance, reducing carbon impact, and creating healthier, more efficient spaces for our clients and communities.

nation’s largest office-to-residential adaptive reuse at 25 Water Street, converting a 1960s-era structure into 1,300 high-performance residential units. With a 10-story overbuild and upgraded MEP systems, the project highlights the potential of reuse in tackling urban carbon emissions. By extending the life of existing infrastructure rather than building new, this effort significantly reduced embodied carbon. Natural daylighting, modernized systems, and a preservation-first approach also contributed to the project’s sustainability success.

At the University of Pennsylvania, LF Driscoll completed a 113,000+ sf research hub designed to advance energy innovation. The facility is LEED Platinum certified and features a fumehood–intensive lab layout supported by a custom HVAC system using chilled beams, radiant flooring, and energy recovery units. The building’s unitized curtain wall integrates deep ETFE shades—designed for thermal efficiency and visual impact—while BIM coordination helped reduce waste during the lab fit-out.

This five-story automated robotics fulfillment center was built on a 147acre site in just 16 months, with 1,366 parking stalls and critical off-site infrastructure. Layton Construction prioritized environmental protection throughout, including wetland preservation and safeguarding habitats for endangered species. To minimize carbon impact, the team used CarbonCure concrete technology and tracked embodied carbon across the project. A local waste hauler was engaged to sort and divert recyclables—generating monthly waste logs and maximizing landfill diversion.

rethinking construction waste Across STO Building Group, our teams are actively rethinking material use, piloting new recycling practices, and building partnerships that support a more circular economy in construction.

DRIVING GYPSUM CIRCULARITY AT SCALE

Across the US Northeast, Structure Tone is leading a multi-phase effort to reimagine gypsum wallboard (GWB) waste as a valuable material resource. What began as pilot projects in New York and Boston have grown into a multi-regional strategy to eliminate GWB landfill waste and cut embodied carbon.

Since 2023, nine pilot projects in Boston totaling 873,000sf have diverted 515 tons of clean gypsum wallboard offcuts through site separation and downcycling with USA Gypsum— keeping the equivalent of over 10.7 acres of board out of landfills and avoiding 67.48 MTCO₂e.

In 2025, the program expanded to projects in Connecticut and New Jersey with a major upgrade: recycling. Instead of downcycling, 48.21 tons of clean board were sent to CertainTeed for full material reintegration. This approach helped avoid 16.4 MTCO₂e and delivered a 160% increase in carbon savings compared to downcycling.

REDUCING SINGLE-USE PLASTICS From eliminating plastic water bottles and packaging to rethinking supplier deliveries, Structure Tone London is pioneering efforts to reduce single-use plastics on site. At select London projects, the team has partnered with vendors to replace shrink-wrap and foam protection with reusable or recyclable alternatives—helping prove that small shifts can lead to meaningful impact. Click to learn more.

VOICE OF CIRCULARITY In honor of Zero Waste Week 2025, STOBG explored material circularity on the Building Conversations podcast. From drywall recovery and supplier collaboration to jobsite waste tracking, this three-episode series features experts across our industry exploring circular practices. Click to listen now.

MASS TIMBER: The Carbon Sequester Materials matter. Because trees sequester carbon, a mass timber structure substantially curbs emissions when compared to conventional concrete and steel. Even in hybrid mass timber buildings—when concrete, steel, and timber are combined—there’s significantly less concrete involved.

Learn more about mass timber at STOBG on our podcast.

MIXED-USE, TX

HIGHER EDUCATION, SC

COMMERCIAL, AR

R&D FACILITY, NJ

MIXED-USE, OR

This is one of the largest Southern Yellow Pine (SYP) mass timber projects in the United States. The vibrant mixed-use development includes office spaces and retail areas, all centered around a communityfocused design that emphasizes sustainability and wellness.

This project blends modern design with mass timber construction in an academic setting. The building will include teaching and research labs, faculty and staff offices, classrooms, and collaboration spaces necessary to support both its teaching and research missions.

Spanning 350 acres, this retailer’s new HQ is one of the largest mass timber campus projects in the world. Designed to accommodate 14,000+ employees across multiple interconnected buildings, this project is setting the standard.

This research campus showcases the innovative use of mass timber in a hybrid, life sciences structure. The facility houses cutting-edge laboratories and collaborative workspaces designed to foster creativity.

This new building is a threesided, five-story mixed-use development featuring residential, retail, and office space. The structure was built using CLT and is hallmarked by its cantilevering and corner windows set at varying angles during construction.

60,000 metric tons of carbon have been sequestered through STOBG mass timber projects

Advancing Transparency through Disclosure Reporting

At STOBG, we believe sustainability performance must be measurable, verifiable, and accountable. In 2025, we continued our work to track operational and embodied carbon, benchmark progress against global frameworks, and empower smarter decision-making through data.

TARGET TRACKING TOOLS We use a suite of specialized digital tools to measure and manage environmental performance in real-time.

Social value impact tracking

DECARBONIZATION IN PRACTICE Several of our builders—Structure Tone and Structure Tone International—have signed onto the Science Based Targets initiative (SBTi), committing to measurable emissions reductions aligned with climate science. These efforts span all three scopes of emissions and are rooted in practical, project-level strategies:

SCOPE 1 – WHAT WE BURN We are phasing in electric vehicles and renewable fuel sources for jobsite and company-owned equipment.

Carbon accounting & reporting

Waste & resource efficiency

SCOPE 2 – ENERGY WE BUY Our offices continue to implement energy efficiency upgrades and purchase renewable electricity credits to offset fossil fuel use.

Embodied carbon material comparison

SCOPE 3 – BEYOND THE JOBSITE Our teams are reducing unnecessary travel, salvaging materials before demolition, maximizing recycling, and specifying products with low global warming potential (GWP) and verified environmental product declarations (EPDs).

We’ve measured our carbon footprint across all three emission scopes using the Greenhouse Gas Protocol and had our data independently verified. This means we can now accurately track and report emissions by individual client project—making our reporting more detailed, transparent, and useful for decision-making.

Learn more about STOBG’s commitment to climate resilience in our Climate Risk Mitigation Report.

LEED tracking & ESG jobsite reporting

BUILDING ACCOUNTABILITY INTO EVERY LAYER We also evaluate business practices through EcoVadis, a globally recognized sustainability rating platform. Structure Tone and BCCI are assessed across four key areas: Environmental Impact, Labor & Human Rights, Ethics, and Procurement Practices. This assessment provides us and our partners with consistent benchmarks for ethical and sustainable performance across our supply chain.

Sustainability Stories: Local actions, Lasting impact When it comes to sustainability, our people, projects, processes, and partnerships set us apart.

Take a look at some of the standout 2025 sustainability stories from across our family of companies. Read more STOBG sustainability stories here.

RC ANDERSEN TURNS OLD INTO GOLD In partnership with IDI Logistics, RC Andersen is transforming a decades-old office site in Piscataway into a high-throughput, 155,000sf industrial space. The team prioritized onsite material recovery and recycling, turning demolition waste into building blocks for the future. Learn more.

STRUCTURE TONE LONDON STRUCTURE TONE DUBLIN DEPLOYS THE WASHBOX ROCKET

STNY NAMES FIRST SUSTAINABILITY CHAMPION

LF DRISCOLL EARNS SUSTAINABILITY HONORS FOR VAGELOS LAB

Structure Tone Dublin became the first contractor in Ireland to introduce the Washbox Rocket system on site—a closedloop, mobile tool-cleaning station that significantly cuts water use and microplastic pollution.

Structure Tone New York recognized Dunia Simunovic as their first-ever Sustainability Champion for her leadership in embedding LEED goals into every stage of project delivery. On her project, Simunovic led by example and demonstrated what it means to build responsibly.

LF Driscoll’s work on the University of Pennsylvania’s Vagelos Laboratory for Energy Science and Technology earned the Sustainable Building Operations Award at the 2025 Groundbreaker Awards. The project showcases how thoughtful construction can support high-performance research in energy and sustainability. Learn more.

TAKES ACTION Structure Tone London showcased its sustainability leadership in 2025 by sponsoring A Circular Revolution, a landmark industry event focused on rethinking construction through the lens of circular economy. Backed by action, their teams recycled over 100,000 linear meters of copper cable, diverted over 180,000kg of waste from landfills, and partnered with social enterprises to extend material life. Learn more.

SustainAbility Stats Top 5 Green Contractors

by Sector

150

MILLION SF OF LEED REGISTERED SPACE

317

GREEN BUILDING CREDENTIALED PROFESSIONALS

$4.05B

MEMBER OF THE US GREEN BUILDING COUNCIL

800

OF ANNUAL GREEN CONTRACTING REVENUE IN 2024

IN ENR’S TOP 100 GREEN BUILDING CONTRACTORS FOR 2025

LEED PROJECTS

17

53

5

WELL ACCREDITED PROFESSIONALS

STRATEGIC ALLIANCE PARTNERS WITH CREATORS OF THE WELL™ BUILDING STANDARD

#6

FOUNDING MEMBER OF THE WELL LIVING LABORATORY

MEMBER OF THE IRISH GREEN BUILDING COUNCIL

WELL BUILDING STANDARD REGISTERED PROJECTS

30

BREEAM UK REGISTERED PROJECTS

MEMBER OF THE UK GREEN BUILDING COUNCIL

WELL HEALTH-SAFETY RATING CERTIFIED PROJECTS

3

LIVING BUILDING CHALLENGE CERTIFIED PROJECTS

MEMBER OF THE CANADA GREEN BUILDING COUNCIL

03

People & Culture

Together WE Thrive STO Building Group cares about its people. We go beyond compliance, prioritizing mental health, jobsite culture, and worker protections to ensure every team member feels supported and secure. We developed our Thrive 360° program in 2025 to promote employee well-being in all its forms. We invest in our people and empower them to reach their full potential. Through benefits, education, leadership resources, well-being initiatives, and community engagement, Thrive 360° advances the employee experience and builds a culture of excellence—because when we thrive, STOBG thrives.

CAREER

SOCIAL

FINANCIAL

PHYSICAL

COMMUNITY

Grow with purpose through learning, development, and leadership tools.

Build meaningful connections through celebrations and events.

Plan your future with financial programs and resources.

Stay healthy with benefits and programs for you and your family.

Make an impact through initiatives that strengthen our communities.

Women in construction STO Building Group Women in Construction (STOWIC) is an internal, inclusive group dedicated to advancing opportunities in the construction industry. The group focuses on creating professional development experiences for men and women, fostering industry-wide networking for individuals at all levels, and giving back to communities by supporting women and girls who aspire to build careers in construction.

WIC Summit

Breast Cancer Awareness Month

Structure Tone New York hosted STOWIC’s fourth Women in Construction Summit, themed Client State of Mind: Foundation for Partnerships. Leaders from Structure Tone New York and Pavarini McGovern were in attendance. From business development strategies and skill-building sessions to a fireside chat with valued clients and a worksite visit, the event reflected the organization’s commitment to cultivating strong, relationships across the markets we serve.

The STOBG family came together to raise awareness and funds for the fight against breast cancer. Through events like walks, Wear Pink Wednesdays, and brunches, teams from Los Angeles to Dublin showed up to promote early detection and support breast cancer survivors.

BUILDING A DIVERSE

WORKFORCE

STO Building Group is a proud supporter of the ACE Mentor Program of America (ACE). Founded in 1994, this program provides nocost after-school opportunities to connect high school students with experts in the design and construction industry. By engaging students and communities traditionally underrepresented in the industry, ACE works to build a large, diverse, and better prepared workforce.

Structure Tone New York hosted ACE Team #20 for a handson scavenger hunt. During the event, mentees used drawings to explore an active construction site, identifying structural and MEP elements in the field. The event linked classroom learning to real-world application while promoting teamwork, curiosity, and a deeper understanding of construction.

ACE Mentors Webinar During Construction Inclusion Week, STOBG released a video webinar featuring several of STOBG’s ACE participants. The event also featured Diana Eidenshink, President of ACE, and Greg Dunkle, COO of STOBG and an ACE Board of Directors member. During the event, participants spoke about the value of the program and shared info with our staff about how to get involved as potential mentors.

The NExt Generation

Our teams work to inspire the next generation of builders. Workforce development goes beyond building projects, it strengthens the communities we serve. Through partnerships with Perryman Construction, Capital City College, and local schools and organizations in London, our teams are helping open doors for students, job seekers, and future industry leaders by providing real engagement, hands-on experiences, and opportunities to explore meaningful career paths.

LF Driscoll

Structure Tone London

LF Driscoll partnered with Perryman Construction to host a breakfast event featuring a panel discussion, Q&A session, and jobsite tour. Women from both LF Driscoll and Perryman took part in the panel, sharing their career journeys and insights into their current roles.

Structure Tone International hosted a jobs fair at the Edith Neville Primary School Hall, collaborating with our supply chain partners on local recruitment opportunities within London.

Opportunities for All

Recruiting the Future

Our London team also partnered with Capital City College to deliver a series of engaging career insight workshops to empower students with the tools and confidence to take their next professional steps.

Investing in our Future

STOCK Ownership STO Building Group reorganized its ownership structure in 2017 to pave the way for employee ownership. Today, employees have the opportunity to buy shares in STOBG’s parent organization, GISI. By giving employees the opportunity to become owners, we’ve fostered an environment where our people have a stronger connection to our company’s success. Our people have always been committed to our mission, but ownership creates a deeper sense of pride and accountability for team and company performance.

This approach is rare in our industry, offering every employee the chance to have a stake in our growth. Over half of our people now own shares in the company, purchased directly or through payroll deduction. To further support participation, we currently provide a 20% RSU match on share purchases, which vests into Class A shares after three years.

EMPLOYEE STOCK PURCHASE PROGRAM: INVESTING IN STOBG’S SUCCESS

53.5%

of staff are owners as of Q3 2025

Investment options

employees can buy shares directly or enroll in payroll deduction

Share price increase

via biannual independent valuation

2025 dividend issued to shareholders

EMERGING PROFESSIONALS STO Building Group’s Emerging Leaders program is a year-long initiative designed to cultivate the next generation of leaders. Bringing together talent from across departments and companies, the program promotes collaboration and professional growth through interactive workshops, leadership exercises, and networking opportunities. Participants gain a deeper understanding of STOBG’s culture while building skills to lead with impact. By fostering innovation and cross-functional connections, Emerging Leaders empowers participants to drive meaningful change within the organization and influence progress across the industry.

STOBG EMERGING LEADERS

STOBG’s Rotational Project Engineer (RPE) Program

STO Building Group’s Rotational Project Engineer (RPE) Program guides participants through rotations across several major disciplines, including operations and estimating. Over the course of 2.5-3 years, RPEs choose electives in fields like sustainability and business development. They also have quarterly check-ins with HR and BU leaders, attend cross-functional events, and gain a chance to network with STOBG executives. Each year, the RPE Boot Camp brings together RPEs and PEs from across the STOBG family. This year, 65 participants from 13 STOBG business units gathered in Philadelphia, PA, for another standout event.

From the field The Superintendent Academy (SA)

Superintendent Roundtable Established in 2022, STO Building Group’s Superintendent Roundtable (SRT ) brings together highly engaged superintendents from across the STOBG family to provide a voice for this important group. The group meets regularly and comes together in-person twice a year. At their sessions, supers share best practices, develop peer networks, and propose improvements directly to executive leadership. 2025 discussion topics included: • • • • •

Onboarding Early career development Safety Financial literacy Mental health

was the first big initiative of the SRT. The group was launched in 2024 to empower early-career supers through education, collaboration, and leadership development. At events, rising superintendents gather to grow their peer network and learn what it takes to be a world-class superintendent. Sessions cover topics like project planning, safety, logistics, scheduling, and change management, as well as soft skills like communication and self-awareness.

Learning 360°

Learning 360° combines industry training and in-house expertise on construction and business topics— from software skills and client relations to safety. This curated program empowers employees to own their growth, manage goals, performance, certifications, and knowledge, positioning our people and business as industry leaders from the inside out.

OUR COMMITMENT TO GROWTH At STOBG, we strive to create a workplace where every employee feels inspired by their career path. We listen to our employees through a variety of methods.

SURVEYS Our annual Gallup engagement survey gathers valuable employee feedback and delivers actionable insights to strengthen our workplace culture.

CENTERS OF EXCELLENCE & INNOVATION Cross-functional focus groups drive improvements in Operations, Purchasing, and VDC processes.

KNOWLEDGE EXCHANGE An internal online hub for collaboration and learning, enabling employees to share insights, best practices, and expertise in real time.

EMPLOYEE BENEFITS: HEALTHY, WEALTHY & WISE

At STOBG, we leverage the power of our platform to offer more value to our people.

HEALTHY • • • • • • •

Medical Dental Prescription Drug Vision Mental Health Adoption & Surrogacy Assistance Fertility Assistance

•

Time Away

WEALTHY • • • • • • •

Health Savings Accounts Flexible Spending Accounts 401(k) Retirement Plan Company Stock Ownership Digital Budgeting Tools Transit & Parking Accounts Tuition Reimbursement

WISE • • • • • • • • • •

Short-Term Disability Long-Term Disability Accident Insurance Life Insurance Home & Auto Insurance Critical Illness Insurance Hospital Indemnity Insurance Retirement Concierge Group Legal Identity Theft Protection

•

Pet Insurance

04

Our Culture of Safety

O U R S A F E T Y 3 6 0° P H I L O S O P H Y In 2025, we recorded our lowest Total Recorded Incident Rate (TRIR) and Lost Time Incident Rate (LTIR) in company history. This is especially significant because we crossed 60 million labor hours on projects, more than we’ve ever logged before. Adding to these amazing results is the fact that four STOBG businesses worked the entire year without any lost time incidents—a truly inspirational feat.

What that proves is that for us, safety is more than a metric; it’s a core value woven into every aspect of our work. Success means that real people return home safely at the end of each day.

AWA R E N E S S

POSITIVITY

The program fosters a 360-degree view of safety, physically and philosophically.

That means that we look out for one other’s physical and mental safety, speak up about potential safety issues, and are as invested in safety as our safety staff.

Safety 360° relies on positive reinforcement to inspire project teams and employees at all levels to achieve the highest level of safety. Regular feedback, engagement, and coaching are at the program’s core and drive STOBG’s efforts to foster a lasting and positive safety culture across the organization.

SHARED RESPONSIBILITY Each and every employee receives safety coaching. We believe that the best way to increase awareness and action is to increase responsibility, so our superintendents, project managers, and even our office-based employees are as engaged in safety as our dedicated safety department team members.

B E H AV I O R

B U I L D I N G C U LT U R E

Behavior is the primary contributing cause of over 80% of accidents. With that in mind, we are helping staff take a more active role in supporting a strong safety culture that solicits feedback, engages the workforce, and empowers people to make a difference.

Upon joining STO Building Group, new staff attend Safety 360° coaching to learn about our safety culture of caring and engagement. We also work with our clients to make sure they understand and play a role in this culture of safety.

E V E R Y B O D Y, E V E R Y W H E R E , E V E R Y D A Y

MENTAL HEALTH AT STOBG YOU MATTER. WE CARE.

The construction industry faces unique challenges that can affect mental health. In fact, the suicide rate in construction is more than four times higher than in the general public.

At STOBG, we’re working to change that.

Mental Health Toolkits The committee created toolkits for US and International-based employees that provide a one-stop-shop for mental health. These toolkits include links to such resources as:

• • • • •

Hotline numbers Free courses Counseling services Articles Self-care tools

We regularly lead campaigns to highlight mental health awareness, encourage checking in on one another, and share the many mental health resources the company provides access to. This year during Construction Suicide Prevention Week, STOBG joined thousands of others across the country in raising awareness and honoring the lives our industry has lost to suicide through a moment of silence on our jobsites.

London’s On-Site Health & Well-being Screenings. Empowering the people who deliver our projects through excellent health and well-being education continues with Structure Tone London’s onsite health and lifestyle screening, carried out by an experienced well-being coach. The comprehensive check includes measuring blood pressure, heart rate, cholesterol, glucose levels, body composition details and metabolic rate, including lifestyle satisfaction questions, generating a health dashboard for the individual to take away.

When Intention Meets Action Structure Tone Dublin’s Healthy Foundations Initiative Supporting the health and wellbeing of our workforce is a core responsibility at Structure Tone Dublin. This year, the Healthy Foundations initiative brought that commitment to life by integrating practical wellbeing support directly onto the jobsite.

Delivered over several weeks at a city-centre project, the initiative focused on embedding care into everyday operations through health education, catered healthy meals, and inspiring guest speakers. One of the program’s highlights was a week-long run-a-thon in support of The Lighthouse Charity, during which team members collectively logged more than 1,300 kilometers and raised over €21,000 to support mental health services within the construction community.

The Lighthouse Charity also led on-site toolbox talks designed to encourage open conversation and increase mental health awareness. In partnership with the Construction Workers’ Health Trust, free on-site health screenings were offered, with more than 40 site operatives participating during the first week alone.

Healthy Foundations reflects a simple principle: when we invest in the wellbeing of our people, we build stronger projects, safer sites, and more resilient communities.

A C u lt u r e O f S a f e t y CELEBRATING SAFETY

PROVIDING SUPPORT

SAVING LIVES

For National Safety Month, our family of builders held stand downs and other events to mark the occasion.

Our teams used this time to call attention to the importance of culture, developments in PPE, and supporting our employees on and off the job. Many of you even spotlighted topics that are sometimes forgotten in workplace safety—like mental health, CPR, and lunch breaks.

Construction has the second-highest rate of pain medication/opioid misuse in the US. Our Pavarini North East team has been facing that challenge head on, working with Liberation Programs to host Narcan training and distribute life-saving nasal spray kits to all workers.

Across STOBG, our teams host AED/CPR trainings regularly. This year, a Layton data center project team put training into action when a colleague suffered a heart attack. The project team used the on-site AED to save a life, recognizing the jobsite medic for his quick actions by naming him the Layton Safety Champion of the Month.

CORY DUDLEY

STOBG Safety 360° awards Excellence deserves to be recognized. Our annual STOBG Safety 360° Excellence Awards are the highest level of recognition in the company to honor those project teams who truly went above and beyond expectations to keep their jobsites safe.

small projects

medium projects

large projects

Pavarini North East AIG Nation Hall (Westport, CT)

Structure Tone Philadelphia

Philadelphia Flyers Rink and Ice Replacement and Equipment (Voorhees, NJ)

Structure Tone London

For this three-story upgrade of a historic building, the Pavarini team not only renovated the full interior but also installed a first-of-its-kind flood prevention system.

This specialized effort required an expert team of subs with excellent safety records and required OSHA 30 training. The team kept the focus on worker health and safety throughout the project, including hosting Narcan training, fall protection training, and required updated PPE. With this behavior engrained in the team, our project partners spotted several “good catches” that prevented safety issues from happening and led to an incident-free project.

This project included a replacement of two ice rinks in the Philadelphia Flyers training facility in Voorhees, NJ—all before the team returned for training. With a tight schedule and a high-profile client, the Structure Tone team had to balance safety with quality and efficiency. To do that, the team brought in subs who already share our Safety 360° culture and could safely deliver the high-risk nature of some of the work, from implementing crane picks to using heavy machinery indoors. The team recognized a safety champion each month with Home Depot gift cards and held numerous safety trainings, stand-downs, and tool talks.

The result? Zero recordable hours or lost-time injuries.

This CAT B fit-out of the 20 Ropemaker Street building in London spanned 375,000sf and included upgrades to the staircases, health suites, auditorium, gym, and catering space. For such an extensive project, the team developed an extensive plan to cultivate and activate a Safety 360° culture—even including charitable events and industry toolbox talks. From safety stand-downs and training sessions to fire and defibrillator drills, the team had a structured approach to safety training, prevention, reporting, and correction. The client was heavily engaged in this culture as well, awarding gift cards and prizes to those who made notable strides to keep the jobsite safe.

(under $10M)

($10M–$100M)

($100M or more)

20 Ropemaker Street (London, UK)

Safety Stars Our LF Driscoll team sets the bar for safety high—and keeps it there.

This year, two LFD projects achieved “Star” status in the Occupational Safety and Health Administration’s (OSHA) prestigious Voluntary Protection Programs (VPP). Participating in this rigorous, esteemed program allows project teams to certify that they meet OSHA’s highest standards for workplace safety.

CLICK TO READ MORE about what it takes to achieve VPP Star status.

VPP Star status, we are committed to continuously improving safety “ Bandy achieving combating complacency,” says Stephen Kanter, senior safety manager at LF Driscoll. “LF Driscoll’s commitment to safety through initiatives like Safety 360° showcases how a VPP certified site can influence safety practices throughout an organization.”

CELEBRATING SAFETY

Abbott/Layton >

Cal/OSHA Golden Gate Award: Huntington Health Medical Office Building project

Ajax >

ABC Diamond STEP Award

BCCI >

Excellence in Safety Award, Construction Employers Association (13th time)

layton Associated General Contractors of Utah Diamond Achievement of Safety Excellence Award > Associated General Contractors of America (AGC) Construction Safety Excellence Awards: Construction Management, over 1 Million Work Hours >

LF Driscoll General Building Contractors Association (GBCA): Calder Gardens > GBCA: Children’s Hospital of Philadelphia, Main 4-OR Boom and Blanket Replacement > GBCA: Cobbs Creek Foundation, TGR Learning Lab > GBCA: Hospital of the University of Pennsylvania, Dulles 4 Endoscopy > GBCA:Pennsylvania Hospital, Procedure Room, Interventional Neurosurgery CT & Farm Journal Infusion Pharmacy >

Structure Tone Dublin >

Fit-Out Awards Excellence in Health and Safety

Structure Tone New York >

ENR New York Award of Merit Safety, L’Oréal Research & Innovation Center

Structure Tone Southwest Associated Builders & Contractors (ABC) Diamond STEP Award – Dallas > ABC Diamond STEP Award – Houston > ABC Diamond STEP Award – Austin > ABC Diamond STEP Award – San Antonio >

Setting standards & raising the bar Simply following safety protocols isn’t how we define a safe culture at STOBG. We are constantly assessing, improving, and learning from each other to continue leading the way in our industry.

1

SAFETY & HEALTH MANUALS

Our corporate Safety & Health Program defines safety and loss prevention management and the implementation requirements for our construction operations.

Our manuals, which are available as references at all STOBG offices and project sites, serve as the foundation for all STOBG offices and project sites, and for our projectspecific programs.

2

SAFETY AUDITS & MONITORING

As part of the daily course of our construction management services, we monitor the standards and procedures for protecting the safety of the public, local residents, and our construction crews throughout the project. We conduct thorough audits to make sure our teams are adhering to our standards and procedures and that everyone has a voice in keeping our sites safe.

3

PRE-TASK PLANS (PTP)

Creating PTPs is vital to working safely. We created a series of videos to educate our trade partners on how to develop quality PTPs. Offered in both English and Spanish, these videos explain why we make PTPs and what goes into them to make sure a project team has the tools and safeguards in place before they begin work.

4

STOBG SAFETY COUNCIL

Our employees—from jobsite crews to our executive leadership— are invested in leading the industry when it comes to safety. That’s why our CEO, Bob Mullen, created the STOBG Safety Council, a group of STOBG executive leaders, industry partners, and client representatives who share information and examine new ideas and best practices. This year the council tackled subjects ranging from working with subcontractors to mitigating risk, to upcoming OSHA policies, to implementing the new helmet style across the company.

5

SHEQ COMMITTEE

Our board of directors’ Safety, Health, Environment, and Quality (SHEQ) committee focuses not only on those topics, but also training, social responsibility, measurement, and progress. This year, the committee: Addressed distractions to focus attention on core safety priorities > Oversaw efforts to improve data analytics > Required executive leadership engagement in all “lost time” accident reviews >

2025 SAFETY 360° PERFORMANCE When you foster a behavior-based culture of safety, awareness goes up and incidents go down. Even with over 63 million project hours logged in 2025, we outperformed industry averages in every safety category.

TRIR

TRIR

STOBG + ALL SUBS

STOBG ONLY

1.19

.45

*TRIR: Total Recordable Incident Rate *EMR: Experience Modification Rating *LTIR: Lost Time Incident Rate

EMR .53

LTIR

LTIR

STOBG + ALL SUBS

STOBG ONLY

.31

.13 CLICK HERE To listen to Keith Haselman speak about Safety Innovations

05

Community Impact

We build communities We are so proud of our employees’ efforts to those in need, from helping fight hunger, to providing opportunities for children in underserved communities, to raising money for diseasefighting research. Here we highlight just a handful of the many, many ways our employees and our organization invest in the success of those around us. While these numbers are impressive, they don’t include the millions of dollars our employees help raise through their roles as board members and volunteers in charitable organizations across our communities.

15,600 $3.7M Hours Volunteered

Additional $10M in fundraising donated through executive board memberships and charitable events

Helping Hands

Our commitment to giving back is driven by the belief that volunteering creates real and lasting impact. Across London, Boston, and beyond, our teams continue to roll up their sleeves—donating time, care, and resources to organizations that lift up children, families, seniors, and neighbors in need. From preparing meals and collecting gifts to hosting community events and supporting local charities, our people consistently show that meaningful change starts with showing up.

ST London Structure Tone London gave back to two Age UK organizations, with the 20RM site team hosting a pampering afternoon for elderly clients at the King’s Cross Day Centre and the project team volunteering at Age UK Camden to improve the center’s gardens and outdoor spaces, creating more welcoming environments for the communities they support.

Members of Structure Tone London’s 20RM site team visited the Age UK Day Centre in King’s Cross to host a special pampering and wellness session for the clients who use their services.

Structure Tone London volunteers enhancing the gardens at Age UK Camden to create a more welcoming outdoor space for visitors.

Gold tournament teams raised money for such causes as the Mark Bavis Leadership Foundation.

Every year Boston runs in the Cathleen Stone Island 4k to benefit the Outward Bound program.

ST Boston As part of its 40th anniversary, Structure Tone Boston gave back to the community by supporting 40 organizations and events throughout 2025 through volunteering, fundraising, and service initiatives.

Building Healthier Futures We’re dedicated to supporting the well-being of the communities where we live and build. Through charity walks, hospital partnerships, fundraising events, and wellness initiatives, we’re proud to help advance access to care and champion organizations working to improve health outcomes for those who need it most.

Washington Blood Drive

Layton

Get Moving in May

Pavarini NE

The Tommy Fund

Alzheimer’s Association Walk

Abbott Construction hosted a successful blood drive in March that resulted in 21 pints being donated, potentially saving more than 60 lives! Five employees donated for the first time, making a lasting impact.

For the second year in a row, Layton hosted a fun, friendly company-wide competition designed to get everyone moving and support physical and mental well-being. Employees were encouraged to invite coworkers, family, and friends to join the effort, raising over $12,000 in cancer research.

Pavarini North East’s Team Red hit a strike for a cause! The crew bowled their hearts out to raise funds for The Tommy Fund for Childhood Cancer—supporting families and children facing pediatric cancer with strength and hope.

Structure Tone Philadelphia employees joined the Walk to End Alzheimer’s, raising awareness and funds to support those affected by Alzheimer’s and other dementias.

Abbott

ST Philadelphia

Feeding Change Food brings people together—and it’s one of the most meaningful ways we can support our communities. Whether volunteering at local food pantries, donating meals, or partnering with organizations fighting food insecurity, our teams are committed to helping ensure everyone has access to the nourishment they need.

ST London – Luminary Bakery The Structure Tone London team kicked off a sweet new partnership with Luminary Bakery. Luminary supports women who have faced significant life challenges, helping them gain confidence, develop career skills, and thrive through sustainable employment in the bakery. The team is also helping fuel a mission focused on strength, ambition, and opportunity—supporting women in the community.

Structure Tone Southwest – Food Pantry Each year, the Structure Tone Southwest Marketing team takes time to give back—and this year, they spent the day at The Stewpot in Dallas. The team jumped in wherever needed: stocking shelves, unloading donations, and lending a hand to help guests choose their groceries. Together, they helped ensure that more than 196 individuals experiencing homelessness had access to food and support.

KIDS

At STO Building Group, we’re committed to empowering the next generation through education, mentorship, and community programs. From classrooms to construction sites, our teams help inspire curiosity, confidence, and opportunity for kids and young adults.

ABBOTT

ST NEW JERSEY

Over 60 students, families, volunteers, and industry partners—including Abbott Construction—joined forces at the E-Shed Prep Build event to construct three new emergency sheds for Northshore School District.

The Structure Tone family donated and wrapped gifts to support the Adopt-A-Child Christmas Gift Program at Saint Dominic’s Family Services.

E-SHED PREP BUILD

ADOPT-A-CHILD

BCCI

AJAX

RC ANDERSEN

BCCI kept the tradition alive with another successful Backto-School Backpack Drive!

Partnering with Family Giving Tree, the team helped provide backpacks full of school supplies to students in need across the Bay Area.

The Ajax team proudly partnered with Riley Elementary in Leon County School District, sponsoring a classroom by providing supplies, helping with holiday parties, and spending time reading to the students.

RC Andersen volunteers read to preschoolers and handed out mini hard hats— bringing joy and inspiring future builders.

BACK-TO-SCHOOL BACKPACK DRIVE

RILEY ELEMENTARY: A YEAR OF SUPPORT

READING TO PRESCHOOLERS

GIVING BACK WITH MAKE-A-WISH’S REAL ESTATE COUNCIL In 2015, Structure Tone New York helped establish the Make-A-Wish Real Estate Council in partnership with the Metro New York chapter, bringing together AEC experts to help grant complex construction-related wishes for children with critical illnesses. Since then, the Council— now made up of partners across the industry—has granted more than 60 wishes, from backyard basketball courts to home renovations, with construction wish requests tripling since the pandemic.

Wish kid Eden had a very specific vision in mind – a safari bedroom, where she could sleep and play in the jungle, and “read by a tree every night.” Her wish gave her a space full of her favorite things, where she could escape, play and spend time with her siblings.

It was par for the course to grant the wish of an energetic, golf-loving four-year-old who longed for a home putting green. Working with the boy’s family, the REC team found the perfect spot, leveled the yard before pouring concrete, and added fake grass and flags for a realistic putting experience. Now this young golfer can master his short game in no time!

Building Better Communities

Our commitment to community service goes beyond construction—it’s about supporting the organizations that provide safety, stability, and a path forward for those who need it most. From volunteering in local soup kitchens to helping build affordable housing and supporting charities that lift people out of hardship, our teams continue to show up, give back, and strengthen the communities we serve.

ST London

Govan Brown

Layton

Skill & Sweat

Together Academy’s New Home

Members of Structure Tone London’s KGX1 project team recently volunteered with a local charity’s weekly soup kitchen, that supports people who have experienced homelessness and assists them in rejoining society and getting back into work.

Govan Brown engaged with its local Business Improvement Area (BIA) in Toronto to host a community Pollinator Pathway tour. This tour taught community members of the unique biodiversity in the neighborhood and provided insights on Govan Brown’s local urban beehive.

A team of Layton employees recently rolled up their sleeves and braved the heat to support a 13-home neighborhood build with Habitat for Humanity in Nashville.

This marked the Nashville team’s seventh volunteer project with Habitat—and the first since the pandemic—as the “Layton Loves” crew put their construction skills to work building wall panels for a local family in need of affordable housing.

Together Academy has opened its new home at Fitzwilliam 28, delivered by Structure Tone Dublin and SMBC Aviation Capital, offering classrooms, a training kitchen, and a public café to support young adults with Down syndrome.

KGX1 Soup Kitchen

Pollinator Pathway Tour

ST Dublin

Structure Tone Philadelphia employees supporting Team Foster’s mission to ensure no hero is left behind.

Honoring Service, Changing Lives Structure Tone Philadelphia’s Partnership with Team Foster At STO Building Group, veterans and their families hold a special place in our hearts. Which is why Structure Tone’s partnership with Team Foster isn’t just important—it’s personal. It’s a way for us to honor that service and give back in a meaningful way. They sacrificed for us, and now Team Foster advocates for them.

READ MORE

GET MOVING For GOOD

We believe in the power of sports to build community. Through charity events and youth partnerships, our teams support opportunities that strengthen confidence, wellness, and connection.

ST NEW YORK

GLOBAL SERVICES

LAYTON

ST NEW JERSEY

STSW

Employees from Structure Tone New York participated in the 2025 Wall Street Run & Heart Walk, supporting the American Heart Association’s mission to fight heart disease and stroke.

In March, the Global Services team joined the Cycle for Survival charity ride, coming together to raise funds and awareness for rare cancer research supporting Memorial Sloan Kettering Cancer Center.

The Layton Arizona office hosted the 7th Annual Layton Golf Tournament in support of Phoenix Children’s Hospital through 5 For The Fight—raising a recordbreaking $360,790.

Employees from Structure Tone New Jersey were thrilled to sponsor the Peaks for Progress charity event— carving up the slopes with industry friends while raising funds for Hoods to Woods Foundation, an organization connecting inner-city youth to the outdoors through skiing and snowboarding.

Structure Southwest showed up strong at the Fort Bend Hike for Hope, walking in support of American Foundation for Suicide Prevention (AFSP) and raising awareness for suicide prevention and mental health.

2025 WALL ST RUN

CYCLE FOR SURVIVAL

GOLF TOURNAMENT

HOODS TO WOODS

HIKE FOR HOPE

Step up to the Plate LF DRISCOLL – PHILADELPHIA PHILLIES LF Driscoll continues to champion confidence, opportunity, and leadership for young women in sports. In celebration of National Girls & Women in Sports Day, the team joined forces with the Phillies Urban Youth Academy for a lineup of empowering initiatives:

LF Driscoll celebrated with the winners of the Phillies’ All-Star Students Program.

G I R L S & W O M E N I N S P O R T S PA N E L

Y O U T H S O F T B A L L C E L E B R AT I O N

LF Driscoll project manager Sarah Dollarton joined women across the sports industry to share how athletics influence careers and leadership.

LF Driscoll team members, many experienced softball players themselves, volunteered at a clinic for 100 young athletes, coaching skills and boosting confidence.

C A R E E R E X P O S U R E F O R Y O U N G AT H L E T E S

A L L - S TA R S T U D E N T S P R O G R A M

Youth from the Phillies Urban Youth Academy and Nike RBI programs heard directly from LF Driscoll’s Gina Yiantselis about pathways into non-traditional careers for women.

Sponsored by LF Driscoll, this initiative honors 10 exceptional students each year — recognized for excellence both in and outside the classroom.

06

Ethical Business Practices/Governance

Governance & Ethics Governance at STO Building Group is the foundation of trust. Our Compliance & Ethics program is built around six integrated pillars to ensure integrity is embedded in everything we do, from leadership accountability to supplier engagement.

Continuous Improvement & AssuraNce Evolving Governance for the Future

ACCOUNTABLE LEADERSHIP

• Tone from the top • Board oversight

CONTINUOUS IMPROVEMENT • Internal audits • Risk assessments

CLEAR EXPECTATIONS

• Code of conduct • Shared values

CLIENTS FIRST. INTEGRITY ALWAYS.

TRUSTED PARTNERSHIPS • Third-party diligence • Supplier standards

EMPOWERED EMPLOYEES

• Role-based training • Awareness campaigns

SPEAK-UP CULTURE

• 24/7 helpline • Investigation protocols

Internal Audit provides independent assurance that our controls work as intended, and that we keep getting better. In 2025, we began shifting to a technologyenabled enterprise risk management program to complement our ongoing enterprise risk assessments. It reflects our belief that governance at STOBG is a journey of continuous improvement.

2025 Highlights Technology solution onboarded to streamline risk assessment and mitigation plan tracking > Post-audit survey launched to capture auditee feedback and improve the internal audit experience >

Institure of Internal Auditors (IIA) engagement re-established for guidance, training, and certification > Ongoing participation in the Business Ethics Leadership Alliance (BELA) and the Construction Industry Ethics & Compliance Initiative (CIECI) to share insights and collaborate on best practices >

Accountable Leadership Tone from the Top: Independent Oversight

role “ Ourisboard’s to provide

independent, thoughtful oversight that reinforces integrity, transparency, and long-term value.”

—John Kiely, AFR Committee Chair

JANE CHMIELINSKI

NATALIE GOCHNOUR

JOHN KIELY

RICHARD LEE

In 2025, we added the role of President to our leadership team, forming an “Office of the CEO” structure. Establishing this role and the Office of the CEO aligns the STOBG leadership team with our significant growth and allows leadership to identify priorities and oversee and manage strategic direction of the firm as our company and leadership team evolves. Paul Drecksel was named the new STOBG President as of January 1, 2026.

RICHARD LUBERT

DAN MCQUADE

EUGENE REILLY

The independent directors on STOBG’s Board of Directors bring deep expertise and diverse perspectives that strengthen governance and reinforce our commitment to integrity. The Audit, Finance & Risk Committee (AFR) provides oversight of internal audit, compliance, and enterprise risk, helping to ensure transparency, accountability, and continuous improvement.

Compliance & Audit Team OPerational Excellence Through Integrity

Integrity is owned across STO Building Group. Our Compliance & Ethics team sets clear standards and practical guidance, while Internal Audit provides independent assurance over controls and risk management—supporting leaders and teams across our operating companies. As dedicated, full-time functions staffed by seasoned professionals, from attorneys and investigators to CPAs and certified internal auditors, we combine industry expertise with independence to help the business move forward with confidence.

2025 Highlights > New Generative AI Policy > Enhanced Code of Conduct, Supplier Code, and

Anti-Corruption Policy > Refreshed company-wide training on topics such as our Code of Conduct and Anti-Corruption, Anti-Harassment & Discrimination, Anti-Slavery and Human Trafficking, and Gifts & Entertainment policies > Targeted, role-based refresher training on procurement and commercial processes

sometimes think “ People Compliance and Audit

only show up when something goes wrong. But we work with our teams from the start to manage risk, support growth, and keep our promise of integrity to every client.”

—Leah Ramos, Chief Ethics & Compliance Officer

BEST PRACTICES FOR ELECTR ON

IC CO M M UN ICATIO NS

SIONALLY

COMMUNICATE PROFES

FORCED LABOR

rations and throughout

an rights in our own ope

mitted to protecting hum

com At STOBG, we are deeply our supply chain.

handbook and our ies: Including the employee • Follow company polic l media, and IT policies. sment, anti-retaliation, socia anti-discrimination and haras any, client, or project comp al r share confidenti Neve ial: dent confi it • Keep it company permission. ct information without explic age, and content may impa s: Consider how tone, langu • Uphold company value company's. the and and ses, ation purpo reput ess your sively for busin Use your work email exclu lated • Use company channels: Teams) for all business-re any systems (e.g., email, rely on approved comp communications.

G AND HUMAN TRAFFICKIN

, deception, or loited through coercion in which people are exp tion situa any ent prev to s dom.

That includes taking step or restrictions on their free unfair labor conditions force—whether through such as slavery, mpasses serious crimes enco legal term that onal or commercial gain pers to as modern slavery—a for rred ple refe n peo of ofte are tion s These situation All involve the exploita and human trafficking. servitude, forced labor, rights. of fundamental human s tion viola e grav are and occur in unexpected jobsites, exploitation can r these situations on our of us to understand unte all for enco nt may orta you imp that ’s why it’s While we don’t expect other supply chains. That for below. and , look ices to s serv sign ls, ut eria abo mat n ways—across labor, doesn’t seem right. Lear to speak up if something what to look for and how

MUNICATION TOOLS

USE APPROPRIATE COM

unications. account, for business comm any email, not a personal informal discussions, but • Email: Use your comp s may be used for quick, Team soft Micro like • Instant Messaging: Tools l decisions. al documentation or forma avoid using them for offici company ess, texts are considered busin ss discu to used , should not be • Text Messaging: When ess-related communications busin other like . just and, records ssing sensitive information good judgment when discu deleted. As always, use cannot be easily that s ssion discu tive for urgent or sensi • Phone Calls: Preferred documented. platforms for meetings and Teams and other approved Use • Video Conferencing: deletion n. collaboratio chat or Signal that use autoApps: Applications like Snap • Ephemeral Messaging . tions unica ed discussions. for business comm not be used for work-relat features are not permitted by the company should or platform not approved thorized Apps: Any app

NS you may -party hiring processes, our supply chain or third ed labor.

If you have visibility into human trafficking or forc to ted rela s flag red be in a position to spot

LOOKING FOR THE SIG

de: Some warning signs inclu overtime on site or work excessive • Workers are always d usted, sick, or malnourishe exha ear app kers Wor • t of supervisors to speak, especially in fron • Workers seem afraid erpaid being paid or being und ons • Workers report not lled housing with restricti live in employer-contro • Workers mention they ing aten or thre sive abu seem tices held prac • Disciplinary n confiscated or with ation documents have bee • Workers say identific

• Unau

LECT

TAKE A MINUTE TO REF

intended audience. and be shared beyond their can leave a permanent trail standards: Electronic communications our company policies and with aligns tion unica comm al language sending, make sure your al tone and avoid inform Use a respectful, profession • Keep it professional: derstood. misun be could topics, al that denti jokes or sensitive, or confi te channel: For complex, • Choose the appropria email. than r bette be may ing are a call or meet need the information and Only include those who • Share responsibly: authorized to receive it. errors. spelling and grammatical • Proofread: Check for ct recipients and avoid ients: Check for the corre • Double-check recip all recipients. privacy, accidentally replying to need to protect recipients' you ly: Use only when ling • Use the "Bcc" field wise y All" responses when emai or prevent unnecessary "Repl reveal nally entio maintain confidentiality, unint can it "Reply All," as using avoid , Bcc'd e you’r a large group. If tion policies and keep that you were included. to follow company reten unications: Remember other communication tool.

• Retain business comm her by email, text, or any whet , tions unica comm business-related

IDENT HOW TO REPORT AN INC reporting of forced labor and human trafficking e working for ention, detection, and

The prev y of everyon ly chain is the responsibilit in our business and supp us or on our behalf. edied labor, report it imm human trafficking or forc r, Safety, the ComIf you witness or suspect urce (e.g., your manage reso rnal inte iate ropr ately to an app an Resources). pliance Department, Hum is our 24/7 helpline which nymous, you can contact If you wish to remain ano ding Group.

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PLACE LOGO HERE this layer) (left align to box then hide

Empowering Employees

Before

“Seeing Compliance as

partners is extremely important to us all. We tell our team consistently that asking is the best solution. If you’re unsure, reach out to Compliance. They’re a great resource for us to rely on.”

—Dan Finnegan, Executive VP of Structure Tone New York

INTEGRITY IN OUR EVERYDAY WORK

At STO Building Group, we keep guidance practical and timely with a year-round cadence of reminders, quick reads, and leader messages that meet teams where they work. Highlights this year included: our Compliance Week series with senior leaders on partnering with Compliance from day one, seasonal guidance on holiday gifts and entertainment, field tips for spotting modern slavery indicators, and best practices for electronic business communications.

These communications make policy clear and usable, empowering employees to make sound decisions on the job. And each one reinforces our speak-up channels—a 24/7 helpline (with the option to remain anonymous) and our AntiRetaliation Policy—so concerns can be raised safely and addressed promptly.

TRusted Partnerships

Building Responsibly, Together Our clients and communities count on us to deliver with integrity, and we expect the same from everyone who works with us. We hold our subcontractors, suppliers, and other business partners to the same ethical and legal standards that guide our own work.

This year, we revised our Supplier Code of Conduct to reflect evolving expectations—from the responsible use of generative AI to stronger human rights and environmental commitments.

Through rigorous prequalification, duediligence reviews, and ongoing monitoring, we help ensure that the partners who join our projects operate transparently and share our commitment to ethical business practices.

Our goal is simple: every relationship should strengthen trust in the value we deliver to clients worldwide.

07

Appendix & Additional Resources

As builders, we acknowledge our influential role in the environment. Thus, we align our initiatives with the UN’s Sustainable Development Goals, using them as a guiding framework. This report outlines how our programs contribute to these objectives.

Index

UNITED NATIONS

1. NO POVERTY Adopt-a-Child Back-to-School Backpack Drive Make-A-Wish Real Estate Council Skill & Sweat

SUSTAINABLE

2. ZERO HUNGER

DEVELOPMENT GOALS

Luminary Bakery The Stewpot food pantry KGX1 Soup Kitchen

3. GOOD HEALTH AND WELL-BEING

Poverty

Hunger

Partnership Health

Peace Land Oceans

Education

Climate

Gender Water Energy

Consumption

Community Work Inequality Industry

Our Environmental Policy We Care About Our People Together We Thrive Breast Cancer Awareness Month Employee Benefits: Healthy, Wealthy & Wise Our Safety 360° Philosophy Mental Health at STOBG Celebrating Safety Providing Support Saving Lives STOBG Safety 360° Awards Safety Stars Celebrating Safety Setting Standards and Raising the Bar Washington Blood Drive Get Moving in May The Tommy Fund Alzheimer’s Association Walk Honoring Service, Changing Lives

4. QUALITY EDUCATION ACE Mentor Program Opportunities for All Recruiting the Future Riley Elementary Reading to Preschoolers Together Academy’s New Home

5. GENDER EQUALITY Women in Construction (STOWIC) WIC Summit Women in Sports & Leadership Initiatives

6. CLEAN WATER AND SANITATION Our Environmental Policy The Washbox Rocket

7. AFFORDABLE AND CLEAN ENERGY Our Environmental Policy Mithun Pier 56 Office 15 George’s Quay / Aon SoMA (25 Water Street) Vagelos Laboratory Project Mastodon Rethinking Construction Waste Mass Timber Decarbonization in Practice (SBTi)

8. DECENT WORK AND ECONOMIC GROWTH We Care About Our People Women in Construction (STOWIC) WIC Summit Employee Stock Purchase Program Emerging Leaders Program Rotational Project Engineer Program Superintendent Roundtable & Academy Learning 360° Employee Benefits Safety 360° Philosophy — p. 28 Mental Health at STOBG A Culture of Safety – p.30 STOBG Safety 360° Awards Safety Stars Celebrating Safety Setting Standards and Raising the Bar Governance & Ethics Accountable Leadership Compliance & Audit Team Empowering Employees Continuous Improvement & Assurance

9. INDUSTRY, INNOVATION AND INFRASTRUCTURE We Build Green Rethinking Construction Waste

Mass Timber Target Tracking Tools The Washbox Rocket Setting Standards and Raising the Bar

10. REDUCED INEQUALITIES We Care About Our People Women in Construction (STOWIC) ACE Mentor Program Adopt-a-Child Back-to-School Backpack Drive Make-A-Wish Real Estate Council Habitat for Humanity Career Exposure for Young Athletes

11. SUSTAINABLE CITIES AND COMMUNITIES Our Environmental Policy Mithun Pier 56 Office 15 George’s Quay / Aon SoMA (25 Water Street) Vagelos Laboratory Project Mastodon Rethinking Construction Waste Mass Timber Decarbonization in Practice (SBTi) Sustainability Stories Building a Diverse Workforce The Next Generation Pollinator Pathways Tour

12. RESPONSIBLE CONSUMPTION AND PRODUCTION Mithun Pier 56 Office SoMA (25 Water Street) Project Mastodon Driving Gypsum Circularity at Scale Reducing Single-Use Plastics The Washbox Rocket Turning Old into Gold ST London Takes Action

13. CLIMATE ACTION Our Environmental Policy Mithun Pier 56 Office

15 George’s Quay / Aon SoMA (25 Water Street) Vagelos Laboratory Project Mastodon Rethinking Construction Waste Mass Timber Decarbonization in Practice (SBTi)

14. LIFE BELOW WATER Our Environmental Policy The Washbox Rocket

15. LIFE ON LAND Our Environmental Policy Project Mastodon Pollinator Pathways Tour

16. PEACE, JUSTICE, AND STRONG INSTITUTIONS Building Accountability Together We Thrive Governance & Ethics Empowering Employees

17. PARTNERSHIPS FOR THE GOALS Rethinking Construction Waste SBTi Target Tracking Tools Building Accountability ACE Mentor Program The Next Generation Safety Stars Luminary Bakery Riley Elementary Make-A-Wish Real Estate Council Pollinator Pathways Tour Habitat for Humanity Together Academy Honoring Service, Changing Lives Step Up to the Plate Accountable Leadership Trusted Partnerships

Contact Us HEADQUARTERS 330 W. 34th Street New York, NY 10001

www.stobuildinggroup.com info@stobuildinggroup.com