Summit Materials Inc

Summit recognizes that climate-related risk management is essential to the Company's long-term success and is of vital importance to stakeholders. Responsibility for oversight and integration of climate-related risks and opportunities into our business and operations starts at the top with oversight from our Board that extends through executive senior management at each of our sites and plants. Summit has implemented the following governance oversight structure to monitor the Company's performance and climate-related risk management activities: [...] Summit views sustainability as one of its core values and takes its responsibilities to the lands it operates on seriously. The Board exercises oversight of strategic risks to the Company, which includes climate-related risks and reviews guidelines and policies governing the process by which senior management assesses and manages the Company's exposure to risk and opportunities, including the Company's major financial and operational risk exposures and the steps senior management takes to monitor and mitigate such exposures. [...] In light of the importance of environmental and climate change matters to the Company, its shareholders, communities, customers and employees, and the associated risks the Company faces, the Board oversees environmental and climate-related risk factors and receives regular updates from senior management on the Company's environmental risk profile and key risk mitigating initiatives. In addition, the Board oversees climate-related target setting and receives updates on progress toward target achievement. For example, in 2021, we established and published 2030 and 2050 ESG targets. These targets were developed after extensive internal and external stakeholder analysis and subsequently approved by the Board. The targets are now embedded in Summit's planning process to deliver steady, incremental progress towards those objectives and ensure that business decisions are made with climate considerations in mind [...] The Company's senior management is responsible for oversight and management of climate-related risks and opportunities as well as progressing Summit's ESG strategy. Furthermore, each of the Company's operations has personnel responsible for maintaining compliance with environmental rules and regulations. The Company has a dedicated Enterprise Risk Committee (the "ERC") that continually identifies and evaluates environmental and climate-related risks, including the Company's compliance with environmental rules and regulations. The ERC reports to the Board quarterly. Risk Liaisons at the operating sites and Centers of Excellence are also involved in identifying, reporting and mitigating potential risks to the ERC. Additional information on Summit's ESG governance structure can be found in the 2023 ESG Report.

Summit recognizes that climate-related risk management is essential to the Company's long-term success and is of vital importance to stakeholders. Responsibility for oversight and integration of climate-related risks and opportunities into our business and operations starts at the top with oversight from our Board that extends through executive senior management at each of our sites and plants. Summit has implemented the following governance oversight structure to monitor the Company's performance and climate-related risk management activities: [...] Summit views sustainability as one of its core values and takes its responsibilities to the lands it operates on seriously. The Board exercises oversight of strategic risks to the Company, which includes climate-related risks and reviews guidelines and policies governing the process by which senior management assesses and manages the Company's exposure to risk and opportunities, including the Company's major financial and operational risk exposures and the steps senior management takes to monitor and mitigate such exposures. [...] In light of the importance of environmental and climate change matters to the Company, its shareholders, communities, customers and employees, and the associated risks the Company faces, the Board oversees environmental and climate-related risk factors and receives regular updates from senior management on the Company's environmental risk profile and key risk mitigating initiatives. In addition, the Board oversees climate-related target setting and receives updates on progress toward target achievement. For example, in 2021, we established and published 2030 and 2050 ESG targets. These targets were developed after extensive internal and external stakeholder analysis and subsequently approved by the Board. The targets are now embedded in Summit's planning process to deliver steady, incremental progress towards those objectives and ensure that business decisions are made with climate considerations in mind [...] The Company's senior management is responsible for oversight and management of climate-related risks and opportunities as well as progressing Summit's ESG strategy. Furthermore, each of the Company's operations has personnel responsible for maintaining compliance with environmental rules and regulations. The Company has a dedicated Enterprise Risk Committee (the "ERC") that continually identifies and evaluates environmental and climate-related risks, including the Company's compliance with environmental rules and regulations. The ERC reports to the Board quarterly. Risk Liaisons at the operating sites and Centers of Excellence are also involved in identifying, reporting and mitigating potential risks to the ERC. Additional information on Summit's ESG governance structure can be found in the 2023 ESG Report.

###### GOVERNANCE

To ensure our directors provide effective oversight of management and help protect and create value for all the Company's stakeholders, 8 of 9 of our directors are independent of the Company, as such term is defined by the New York Stock Exchange governance rules for listed companies and our Corporate Governance Guidelines.

When considering Board and committee composition, the Board may consider, among other things, diversity of background, relevant technical skills, age, various and relevant career experience. Indeed, in 2022, the Company amended its Corporate Governance Guidelines and Governance and Sustainability Committee's charter and formally adopted a policy to require any candidate pool assembled to fill a vacancy of the Board to include candidates who are diverse in terms of ethnicity and/or gender.

Our current Directors represent a strong and diverse mix of senior operational and financial executives with materials, technology, supply chain and investor expertise.

The Board is proud of the gender diversity it has been able to accomplish over the last few years. Over 56% of our Board are female and 40% of our executive officers are female, including our Chief Executive Officer.

The Board is committed to clear and accurate financial and non-financial reporting and disclosure and making improvements to policies and procedures it believes necessary to provide the same. The Board's responsibility is one of oversight.

In accordance with the Company's belief that its long-term success includes being good stewards of the environment, the Governance and Sustainability Committee's (the "Governance Committee") responsibilities include the oversight of the Company's initiatives in these areas. Its charter includes:

###### • Oversight of the Company's approach to social responsibility to ensure it aligns with the Company's overall business strategy;
• Oversight and periodic review of external developments which are likely to have significant influence on the Company's reputation and/or its
ability to conduct its business in a socially responsible manner; and

###### • Oversight of Company policies and initiatives relating to the environment with respect to energy management, climate change and
sustainability;

###### • Recommendations to the Board of Directors of a set of corporate governance principles to be included in the Company's Corporate Governance
Guidelines and tracking of developments regarding corporate governance to enable the Committee to recommend to the Board of Directors
changes to the Company's Corporate Governance Guidelines in light of such developments as may be appropriate;

###### • Review of the Company's policies related to political contributions and lobbying
• Reporting to the Board of Directors on the foregoing matters at least annually.

With regards to reporting, Summit's Audit Committee is responsible for oversight of the Company's environmental, social and governance (ESG)
reporting and disclosures (quantitative and qualitative) and related processes and controls, including conformity to the Company's ESG strategy.

In accordance with the Company's belief that its long-term success includes being good stewards of the environment, the Board has established a Governance and Sustainability Committee ("the Committee") to oversee and support the Company's initiatives in these areas. For example, the Committee provides: 1. oversight of the Company's approach to social responsibility to ensure it aligns with the Company's overall business strategy; 2. oversight and periodic review of external developments which are likely to have significant influence on the Company's reputation and/or its ability to conduct its business in a socially responsible manner; and 3. oversight of Company polices and initiatives relating to the environment with respect to energy management, climate change and sustainability; 4. recommendations to the Board of Directors of a set of corporate governance principles to be included in the Company's Corporate Governance Guidelines and tracking of developments regarding corporate governance to enable the Committee to recommend to the Board of Directors changes to the Company's Corporate Governance Guidelines in light of such developments as may be appropriate; 5. review of the Company's policies related to political contributions and lobbying; and 6. reports to the Board of Directors on the foregoing matters at least annually. [...] To further our commitment to our ESG strategy and achieve our vision, in 2021, the Company's Nominating and Corporate Governance Committee changed its name to the Governance and Sustainability Committee. This Governance and Sustainability Committee will provide oversight on the Company's approach to social responsibility and initiatives relating to the environment such as energy management, climate change and sustainability and provide reports to the Board on the foregoing at least annually.

Our Governance and Sustainability Committee [...] Reviewing policies on political contributions and lobbying.

Our Governance and Sustainability Committee [...] Reviewing policies on political contributions and lobbying.

In accordance with the Company's belief that its long-term success includes being good stewards of the environment, the Governance and Sustainability Committee's (the "Governance Committee") responsibilities include the oversight of the Company's initiatives in these areas. Its charter includes: (i) Oversight of the Company's approach to social responsibility to ensure it aligns with the Company's overall business strategy (ii) Oversight and periodic review of external developments which are likely to have significant influence on the Company's reputation and/ or its ability to conduct its business in a socially responsible manner (iii) Oversight of Company polices and initiatives relating to the environment with respect to energy management, climate change and sustainability (iv) Recommendations to the Board of Directors of a set of corporate governance principles to be included in the Company's Corporate Governance Guidelines and tracking of developments regarding corporate governance to enable the Committee to recommend to the Board of Directors changes to the Company's Corporate Governance Guidelines in light of such developments as may be appropriate; (v) Review of the Company's policies related to political contributions and lobbying (vi) Reports to the Board of Directors on the foregoing matters at least annually [...] With regards to reporting, Summit's Audit Committee is responsible for oversight of the Company's ESG reporting and disclosures (quantitative and qualitative) and related processes and controls, including conformity to the Company's ESG strategy.

## SUMMIT MERGER

On February 10, 2025, Quikrete Holdings, Inc. ("Quikrete") acquired all of the common stock of Summit Materials, Inc. ("Summit").   As a result, Summit became a privately held subsidiary of Quikrete, and Summit's common stock ceased trading on the NYSE and is no longer listed on any public market.

In accordance with the Company's belief that its long-term success includes being good stewards of the environment, the Board has established a Governance and Sustainability Committee ("the Committee") to oversee and support the Company's initiatives in these areas. For example, the Committee provides: 1. oversight of the Company's approach to social responsibility to ensure it aligns with the Company's overall business strategy; 2. oversight and periodic review of external developments which are likely to have significant influence on the Company's reputation and/or its ability to conduct its business in a socially responsible manner; and 3. oversight of Company polices and initiatives relating to the environment with respect to energy management, climate change and sustainability; 4. recommendations to the Board of Directors of a set of corporate governance principles to be included in the Company's Corporate Governance Guidelines and tracking of developments regarding corporate governance to enable the Committee to recommend to the Board of Directors changes to the Company's Corporate Governance Guidelines in light of such developments as may be appropriate; 5. review of the Company's policies related to political contributions and lobbying; and 6. reports to the Board of Directors on the foregoing matters at least annually.

In accordance with the Company's belief that its long-term success includes being good stewards of the environment, the Governance and Sustainability Committee's ("the Governance Committee") responsibilities include the oversight of the Company's initiatives in these areas. Its charter includes: 1. Oversight of the Company's approach to social responsibility to ensure it aligns with the Company's overall business strategy; 2. Oversight and periodic review of external developments which are likely to have significant influence on the Company's reputation and/or its ability to conduct its business in a socially responsible manner; and 3. Oversight of Company policies and initiatives relating to the environment with respect to energy management, climate change and sustainability; 4. Recommendations to the Board of Directors of a set of corporate governance principles to be included in the Company's Corporate Governance Guidelines and tracking of developments regarding corporate governance to enable the Committee to recommend to the Board of Directors changes to the Company's Corporate Governance Guidelines in light of such developments as may be appropriate; 5. Review of the Company's policies related to political contributions and lobbying; and 6. Reports to the Board of Directors on the foregoing matters at least annually. [...] With regards to reporting, Summit's Audit Committee is responsible for oversight of the Company's environmental, social and governance (ESG) reporting and disclosures (quantitative and qualitative) and related processes and controls, including conformity to the Company's ESG strategy.

###### GOVERNANCE\n\nTo ensure our directors provide effective oversight of management and help protect and create value for all the Company's stakeholders, 8 of 9 of our directors are independent of the Company, as such term is defined by the New York Stock Exchange governance rules for listed companies and our Corporate Governance Guidelines.\n\nWhen considering Board and committee composition, the Board may consider, among other things, diversity of background, relevant technical skills, age, various and relevant career experience. Indeed, in 2022, the Company amended its Corporate Governance Guidelines and Governance and Sustainability Committee's charter and formally adopted a policy to require any candidate pool assembled to fill a vacancy of the Board to include candidates who are diverse in terms of ethnicity and/or gender.\n\nOur current Directors represent a strong and diverse mix of senior operational and financial executives with materials, technology, supply chain and investor expertise.\n\nThe Board is proud of the gender diversity it has been able to accomplish over the last few years. Over 56% of our Board are female and 40% of our executive officers are female, including our Chief Executive Officer.\n\nThe Board is committed to clear and accurate financial and non-financial reporting and disclosure and making improvements to policies and procedures it believes necessary to provide the same. The Board's responsibility is one of oversight.\n\nIn accordance with the Company's belief that its long-term success includes being good stewards of the environment, the Governance and Sustainability Committee's (the "Governance Committee") responsibilities include the oversight of the Company's initiatives in these areas. Its charter includes:\n\n###### • Oversight of the Company's approach to social responsibility to ensure it aligns with the Company's overall business strategy;\n • Oversight and periodic review of external developments which are likely to have significant influence on the Company's reputation and/or its\nability to conduct its business in a socially responsible manner; and\n\n###### • Oversight of Company policies and initiatives relating to the environment with respect to energy management, climate change and\nsustainability;\n\n###### • Recommendations to the Board of Directors of a set of corporate governance principles to be included in the Company's Corporate Governance\nGuidelines and tracking of developments regarding corporate governance to enable the Committee to recommend to the Board of Directors\nchanges to the Company's Corporate Governance Guidelines in light of such developments as may be appropriate;\n\n###### • Review of the Company's policies related to political contributions and lobbying\n • Reporting to the Board of Directors on the foregoing matters at least annually.\n\nWith regards to reporting, Summit's Audit Committee is responsible for oversight of the Company's environmental, social and governance (ESG)\nreporting and disclosures (quantitative and qualitative) and related processes and controls, including conformity to the Company's ESG strategy.

In accordance with the Company's belief that its long-term success includes being good stewards of the environment, the Governance and Sustainability Committee's (the "Governance Committee") responsibilities include the oversight of the Company's initiatives in these areas. Its charter includes: (i) Oversight of the Company's approach to social responsibility to ensure it aligns with the Company's overall business strategy (ii) Oversight and periodic review of external developments which are likely to have significant influence on the Company's reputation and/ or its ability to conduct its business in a socially responsible manner (iii) Oversight of Company polices and initiatives relating to the environment with respect to energy management, climate change and sustainability (iv) Recommendations to the Board of Directors of a set of corporate governance principles to be included in the Company's Corporate Governance Guidelines and tracking of developments regarding corporate governance to enable the Committee to recommend to the Board of Directors changes to the Company's Corporate Governance Guidelines in light of such developments as may be appropriate; (v) Review of the Company's policies related to political contributions and lobbying (vi) Reports to the Board of Directors on the foregoing matters at least annually [...] With regards to reporting, Summit's Audit Committee is responsible for oversight of the Company's ESG reporting and disclosures (quantitative and qualitative) and related processes and controls, including conformity to the Company's ESG strategy.