Our board of directors recommends that you vote “FOR” the director nominees named in Proposal One of the accompanying proxy statement, “FOR” the ratification of the appointment of PricewaterhouseCoopers LLP as our independent public accounting firm as described in Proposal Two “ONE YEAR” with respect to how frequently we should hold advisory votes onand “FOR” the approval of the compensation of our named executive officers as described in Proposal Three, “FOR” each of the amendments to our certificate of incorporation as described in Proposals Four and Five and “FOR” our adoption of the 2021 Employee Stock Purchase Plan as described in Proposal Six.Three.

Our board of directors has fixed the close of business on January 11, 202212, 2024 as the record date, or the Record Date, for the Annual Meeting. Only stockholders of record as of the Record Date are entitled to notice of and to vote at the Annual Meeting. Further information regarding voting rights and the matters to be voted upon is presented in the accompanying proxy statement.

To be admitted to the Annual Meeting at www.virtualshareholdermeeting.com/AZEK2022AZEK2024 and to ask questions and/or vote, you will be required to enter the 16-digit control number found on your proxy card, voting instruction form or notice previously received. Stockholders may vote in advance of the Annual Meeting at www.proxyvote.com or by telephone at 1-800-690-6903, 24 hours a day through 11:59 p.m. Eastern Time on the day before the Annual Meeting and may vote during the Annual Meeting by following the instructions available at www.virtualshareholdermeeting.com/AZEK2022AZEK2024.

Each share of common stock that you own represents one vote for each of the matters to be acted upon at the Annual Meeting, except that each share of Class B common stock represents zero votes for the election of the two directors referred to above and any other matter relating to the election, replacement or removal of directors.Meeting.

We appreciate your continued support of AZEK.

YOUR VOTE IS IMPORTANT. Whether or not you plan to attend the virtual Annual Meeting, you are urged to vote and submit your proxy as soon as possible by following the voting procedures described in these proxy materials.

TABLE OF CONTENTS

2022 Annual Meeting Information

Matters To Be Voted Upon and Voting Recommendations

2021 PERFORMANCE HIGHLIGHTS

Who We Are at Our Core

Our core values guide how we work—influencing our decisions, our interactions with colleagues and customers and our standards for behavior. It is in part due to our fundamental commitment to living our core values that our employees are inspired to be part of our winning team and culture.

Always Do the Right Thing

We make decisions according to what is right, not what is cheapest, fastest or easiest. We always operate with integrity, transparency and courage.

It Starts and Ends with the Customer

For every action we take, we ask ourselves, “How will this affect our customers?” Our responsibility is to understand their expectations, then surpass them.

Value Every Individual

We strive to truly understand our colleagues’ everyday realities and empathize with their challenges and aspirations. We are committed to providing an inclusive culture where every individual feels engaged, safe, respected and supported with the necessary tools to be successful.

Lead Through Innovation

We consistently bring unique, high-tech and environmentally sustainable products to market. We investare constantly investing in the art of the impossible,future, creating new solutions to address needs customers don’t yet know they have.current and future opportunities.

The Best Team Wins

Our goal is to win, period. We hire and develop the most talented individuals, with a focus on bringing diverse perspectives together in pursuit of this shared goal.

Better Today Than Yesterday

We always ask, “How can we do this better?” We accomplish every goal by rigorously implementing the AZEK Integrated Management System (AIMS). Our continuous improvement methodology includes Policy Deployment, Lean Six Sigma, Sales and Operations Planning, Stage Gate and Digital.

Corporate Governance Highlights

Environmental and Social Best Practices

Executive Compensation Highlights and Pay-for-Performance Alignment

Our executive compensation program is designed by our compensation committee to (i) align executive compensation with our financial and operational performance; (ii) attract, retain and motivate key executives critical to achieving our vision and strategy; and (iii) reward such executives for delivering desired business results and stockholder value, all while protecting against excessive risk taking. Our executive compensation program is described in more detail in the Compensation Discussion and Analysis section beginning on page 2741 of this proxy statement. The following table summarizes our key executive compensation practices:

In keepingWe believe in paying for performance and that tying a significant portion of our named executive officers’, or our NEOs’, compensation to our long-term financial and growth objectives aligns the interests of our NEOs with the interests of our pay-for-performance philosophy, our executive compensation is heavily performance-based.stockholders. For fiscal year 2021,2023, the following factors highlight our commitment to our pay-for-performance philosophy:

In each case, target compensation consists of base salary, target annual incentive awards and long-term incentive awards. For more information, see “Compensation Discussion and Analysis—Fiscal Year 2021—2023—Compensation Tables and Narrative Disclosures—Summary Compensation Table.” Figures may not sum to 100% due to rounding.

Fiscal Year 2023 Pay-for-Performance Alignment

Human CapitalThe following chart shows our three-year and Diversity, Equity and Inclusion

We are committed to social responsibility within our workforce and our community at every level. The full board of directorsone-year total shareholder return, or TSR, and the three- and one-year TSR of our fiscal year 2023 compensation committee regularly engage with our chief executive officer, our chief human resources officer, our vice president of ESGpeer group, as set forth in the Compensation Discussion and other senior leadership onAnalysis below, the S&P Composite 1500 Building Products Index and the Russell 3000, in each case assuming a broad range of human capital management topics, including culture, talent management and succession planning, compensation and benefits, diversity and inclusion and employee engagement feedback gathered from our annual employee engagement survey. Our chief executive officer also periodically leads company-wide employee meetings to provide updates$100 investment on the business and promotefirst day of the period. Relative to our values,peers, our three-year TSR also reflects the impact of our initial public offering, or IPO, in June 2020, including around sustainability and diversity,the fact that we were a newly public company during the period with a significant portion of our common stock held by our former private equity and inclusion initiatives,sponsors, or the Sponsors, as well as smaller group meetingsthe significant rise in interest rates beginning in 2022 that resulted in housing and residential repair & remodel market uncertainty. For fiscal year 2023, our one-year TSR significantly outperformed our peers and market indices, reflecting our strong financial results for the year after navigating a channel inventory recalibration at the beginning of employeesthe year and an uncertain broader macroeconomic and repair & remodel market. In the aggregate, our stock price since IPO increased approximately 30% through our 2023 fiscal year end.

Our strong pay-for-performance alignment is illustrated by the chart below, which compares our CEO’s fiscal years 2023 and 2022 total target compensation to receive their feedback onhis fiscal years 2023 and 2022 realizable compensation, shown against our stock price performance during the businessfiscal year. As reflected below, the compensation realizable by our CEO decreased during the periods when our TSR underperformed our peers and to allow us to identify areasmarket indices and increased during periods where we out-performed. Realizable compensation includes (i) base salary paid during the fiscal year, (ii) actual earned annual cash incentive award amounts paid for the fiscal year, (iii) the value of strengthlong-term incentive awards granted during the fiscal year, measured as of the end of the fiscal year, and opportunities(iv) all other compensation actually paid or received for improvement to ensure continued engagement, satisfaction and retentionthe fiscal year. Realizable compensation is primarily impacted by changes in our stock price, since a substantial majority of our employees.  We have evaluated and adopted certain human capital and human rights management policies to further our commitment to social responsibility and we are focused on hiring and retaining diverse and highly talented employees and empowering them to create value.  Specifically, we have committed to include diverse candidates in any pool of candidates from which employees are chosen. In our employee selection process and the operation of our business we adhere to equal employment opportunity policies and encourage the participation of our employees in training programs that will enhance their effectivenessCEO's compensation is awarded in the performanceform of their duties. We provide attractive benefits that promotelong-term equity compensation, the healthvalue of which is directly impacted by our employees and their families and design compelling job opportunities, aligned with our values and mission, in an energizing work environment. We compensate our employees according to our fair remuneration policies and believe deeply in paying for performance. In conjunction with our 2020 initial public offering, we provided all employees an opportunity for ownership in our company by granting them shares of our Class A common stock and our board of directors and our compensation committee have each approved our adoption of our 2021 Employee Stock Purchase Plan, subject to shareholder approval at the 2022 Annual Meeting and as further described elsewhere in this proxy statement. In 2021, AZEK was named one of Chicago Tribune’s Top Workplaces for creating a culture where our employees feel highly engaged, appreciated and fulfilled, and AZEK was included on Inc.’s list of best-led companies of 2021. Our culture is driven by a shared passion for our values, mission and performance. It is an inclusive culture of innovative, growth-minded individuals committed to always doing the right thing.price.

Director Nominees

Our nominating and corporate governance committee has recommended, and our board of directors has approved, Fumbi ChimaGary Hendrickson, Sallie B. Bailey, Pamela Edwards, Howard Heckes, Vernon J. Nagel, Harmit Singh, Jesse Singh and Brian SpalyFiona Tan as nominees for election as Class II directors at the Annual Meeting. If elected, they each of Ms. Chima and Mr. Spaly will serve as Class II directors until our 2025 annual meeting of stockholders and until their successors are duly elected and qualified, or until their earlier death, resignation, disqualification or removal.

Ms. ChimaGary Hendrickson served as the Chairman and Chief Executive Officer of the Valspar Corporation, a global paint and coatings manufacturer, and was its President and Chief Operating Officer prior thereto. Mr. Hendrickson’s experience as Chief Executive Officer of a global company provides expertise in corporate leadership and development and execution of business growth strategy. He also brings to the board of directors significant global experience and knowledge of competitive strategy.

Jesse Singh is our Chief Executive Officer and President. Prior to joining us, Mr. Singh worked for 14 years at the 3M Company, a manufacturer and marketer of a range of products and services through its safety & industrial, transportation & electronics, health care and consumer segments, and served in numerous leadership roles at 3M, including Chief Commercial Officer, President of 3M’s Health Information Systems business and VP of the Stationery and Office supplies business, which included the iconic Post-it and Scotch Brands. Mr. Singh brings to our board of directors extensive senior leadership experience and a comprehensive knowledge of our business and perspective of our day-to-day operations.

Sallie B. Bailey most recently served as the Executive Vice President and Chief InformationFinancial Officer of Louisiana-Pacific Corporation, a leading manufacturer of engineered wood building products for residential, industrial and light commercial construction. Prior thereto, Ms. Bailey worked as the Vice President and Chief Financial Officer of Ferro Corporation, a global specialty materials company, following an eleven-year career at BECU,The Timken Company, a Washington-based community credit union,global producer of engineered bearings and her decades of leadership and technology experience in the retail and financial sectors, as well as her showcased dedicationalloy steel. Ms. Bailey brings to diversity, women’s employment and inclusion, led our board to the conclusion thatof directors a broad knowledge of corporate finance, strategic planning, banking relationships, operations, complex information technology and other systems, enterprise risk management and investor relations gained through prior service as a senior executive of large global manufacturing companies, including as Chief Financial Officer, and she should continue to servealso has knowledge of and experience with complex financial and accounting functions and internal controls.

Pamela Edwards most recently served as Chief Financial Officer and Executive Vice President of Citi Trends, Inc, a retail clothing chain selling products targeted primarily at urban customers. Previously, Ms. Edwards held various roles at L Brands Inc., one of the world’s leading specialty retailers, including as Chief Financial Officer and Executive Vice President of its Mast Global division, Chief Financial Officer of its Victoria’s Secret division (n/k/a Victoria’s Secret & Co.), and Chief Financial Officer of its Express division. Ms. Edward’s extensive background, especially as Chief Financial Officer of large retail operations and consumer brand experience, brings valuable perspective and expertise to our board of directors.

Mr. SpalyHoward Heckes is the founderPresident and former Chief Executive Officer of Trunk ClubMasonite International Corporation. Prior to joining Masonite, Mr. Heckes served as Chief Executive Officer of Energy Management Collaborative, a provider of LED lighting and currently servescontrols and IoT conversion systems and service solutions and served in various senior operations roles at The Valspar Corporation, including as Executive Vice President and President of Global Coatings and as Senior Vice President, Global Consumer. Mr. Heckes brings to our board of directors extensive experience in corporate leadership, the development and execution of business growth strategies and significant consumer brand and business operating experience.

Vernon J. Nagel most recently served as Executive Chairman of Acuity Brands, Inc., a publicly traded, leading industrial technology company focused on providing building and lighting solutions primarily for commercial and industrial applications, and was Chairman and Chief Executive Officer of Acuity Brands, Inc. from September 2004 until January 2020. Mr. Nagel joined Acuity Brands in 2001 as Executive Vice President and Chief Financial Officer. While at Acuity Brands, Mr. Nagel significantly enhanced shareholder value by introducing innovative technologies, expanding markets served through organic growth and numerous acquisitions, and driving company-wide productivity through the Tecovas,implementation of LEAN business processes. We believe that Mr. Nagel’s extensive experience in strategic, operational, and financial matters as well as executive leadership and corporate governance, over his more than 40-year career, qualifies him to serve on our board of directors.

Harmit Singh currently serves as the Chief Financial and Growth Officer of Levi Strauss & Co., where he is responsible for managing finance, strategy, information technology, strategic sourcing, real estate and global business services functions globally. Previously, Mr. Singh was Executive Vice President and Chief Financial Officer of Hyatt Hotels Corporation. Prior to that, he spent 14 years at Yum! Brands, Inc. in a variety of global leadership roles, including Senior Vice President and Chief Financial Officer of Yum Restaurants International. Mr. Singh brings over 30 years of experience driving growth for global consumer brands and significant experience as a finance executive to our board of directors. Mr. H. Singh is not related to Jesse Singh, our CEO.

Fiona Tan is the Chief Technology Officer for Wayfair Inc. and previously served as its Global Head of Customer and Supplier Technology. Prior thereto, Ms. Tan held various leadership positions at Walmart Inc., including Head of Technology, Walmart US; Senior Vice President, Engineering, Customer Technology, Walmart Labs; and Vice President, Engineering, International Markets, Walmart Labs Strategy and Operations. Prior thereto, Ms. Tan was Vice President, Engineering for Ariba, Inc. and worked for 16 years at TIBCO Software, Inc., as well as for Oracle Corporation. Ms. Tan brings to our board of directors as well asadditional senior executive experience and decades of information technology and cyber expertise, having spent her entire career in information technology roles focused on the boards of directors of several other early-stage growth companies. The board believes that Mr. Spaly’s experience leading high-growth companies as CEOsupporting and serving public companies asimproving business strategy and operations, including with a board member, along with his proven digital and direct marketing experience, will continue to benefit AZEK as we continue to focus on growing our businessexternal constituents, such as customers and further differentiating our leading product offering.suppliers.

Director Skills, QualificationsIndependence and Diversity

Director Independence, Diversity and Refreshment

Stockholder Engagement

Fostering strong, long-term relationships with stockholders and other stakeholders is a key objective. We maintain a robust year-round stockholder engagement program to properly understand stockholder interests, and our senior management and investor relations team routinely communicate with our stockholders to solicit their views with respect to key corporate matters, such as corporate strategy, corporate governance, risk oversight, executive compensation, environmental, social and governance, or ESG, matters and human capital deployment. In fiscal year 2021,2023, we contacted all institutionalinteracted with stockholders who owned at least 2% of our aggregate outstanding shares of common stock (as of September 30, 2021), representing approximately 53%74% of the outstanding shares of our common stock and engaged with all stockholders who responded to our invitation to discuss corporate governance, executive compensation and ESG matters.as of September 30, 2023. The below information highlights our stockholder engagement efforts in 2021.2023. We believe our proactive engagement approach has resulted in constructive feedback and input from stockholders and we intend to continue these efforts.

2021 STOCKHOLDER ENGAGEMENT BY THE NUMBERS2023 Stockholder Engagement by the Numbers

TABLE OF CONTENTS

THE AZEK COMPANY INC.

To Be Held at 10:8:00 a.m. Eastern Time on Tuesday,Friday, March 8, 20221, 2024

This proxy statement and the enclosed form of proxy are furnished in connection with the solicitation of proxies by our board of directors for use at the 20222024 annual meeting of stockholders, or the Annual Meeting, of The AZEK Company Inc., a Delaware corporation, and any postponements, adjournments or continuations thereof. The Annual Meeting will be held virtually via live audio webcast on Tuesday,Friday, March 8, 20221, 2024 at 10:8:00 a.m. Eastern Time. The Annual Meeting can be accessed via the Internet at www.virtualshareholdermeeting.com/AZEK2022AZEK2024 where you will be able to attend and listen to the Annual Meeting live, submit questions and vote your shares electronically at the Annual Meeting. You will not be able to attend the Annual Meeting physically in person.

Our board of directors has fixed the close of business on January 11, 202212, 2024 as the record date, or the Record Date, for the Annual Meeting. Stockholders of record as of the Record Date are entitled to notice of and to vote at the Annual Meeting. The Notice of Internet Availability of Proxy Materials, or the Notice, containing instructions on how to access this proxy statement and our annual report on Form 10-K for our fiscal year 2021,2023, or our 20212023 Annual Report, is first being mailed on or about January 26, 202218, 2024 to all stockholders entitled to vote at the Annual Meeting.

In this proxy statement, the terms “AZEK,” “the Company,” “we,” “us” and “our” refer to The AZEK Company Inc. The mailing address of our principal executive offices is 1330 W Fulton Street #350, Chicago, Illinois 60607.

Notice of availability of proxy materials

On or about January 26, 2022,18, 2024, we expect to mail to our stockholders the Notice. The Notice provides instructions on how to vote via the Internet, mobile device, or by telephone and includes instructions on how to receive a paper copy of our proxy materials by mail. The accompanying proxy statement and our 20212023 Annual Report can be accessed directly at the following Internet address: www.proxyvote.com. You will be asked to enter the sixteen-digit control number located on your Notice or proxy card.

Questions and answers about the proxy materials and our annual meeting

The information provided in the “question and answer” format below is for your convenience only and is merely a summary of the information contained in this proxy statement. You should read this entire proxy statement carefully. Information contained

on, or that can be accessed through, our website is not intended to be incorporated by reference into this proxy statement and shall not be deemed filed under the Securities Act or the Exchange Act, and references to our website address in this proxy statement are inactive textual references only.

Why are you holding a virtual Annual Meeting and how can stockholders attend?

We will be hosting the Annual Meeting via live webcast only. In addition to supporting the health and well-being of our stockholders and other meeting participants during the COVID-19 pandemic, we alsoWe believe hosting our Annual Meeting virtually helps to expand access, facilitate

stockholder attendance, reduce costs and enable improved communication. It also reduces the environmental impact of our Annual Meeting. To participate in our virtual Annual Meeting, visit www.virtualshareholdermeeting.com/AZEK2022AZEK2024 with your 16-digit control number included in the Notice, on your proxy card if you are a stockholder of record of shares of common stock, or included with your voting instructions received from your broker, bank or other nominee if you are a street name stockholder, as described below.

The Annual Meeting live webcast will begin promptly at 10:8:00 a.m. Eastern Time on Tuesday,Friday, March 8, 2022.1, 2024. Stockholders may vote and submit questions while attending the meeting online. We encourage you to access the meeting prior to the start time. Online check-in will begin at 9:7:45 a.m. Eastern Time, and you should allow ample time for the check-in procedures. Participants should allow plenty of time to log in and ensure that they can hear streaming audio prior to the start of the virtual Annual Meeting. If you encounter any difficulties accessing the virtual meeting during the check-in or meeting time, please call the technical support number that will be posted on the virtual meeting platform at www.virtualshareholdermeeting.com/AZEK2022AZEK2024.

What matters am I voting on and how does the board of directors recommend that I vote?

Other than the sixthree items of business described in this proxy statement, we are not aware of any other business to be acted upon at the Annual Meeting. You may be asked to consider any other business that properly comes before the Annual Meeting.

Who is entitled to vote?

Holders of our Class A common stock as of the close of business on the Record Date will be entitled to one vote for each share of our Class A common stock held by them on the Record Date with respect to all matters to be acted upon at the Annual Meeting. The sole holder of our Class B common stock as of the close of business on the Record Date will be entitled to one vote for each share of our Class B common stock held by it on the Record Date with respect to all matters to be acted upon at the Annual Meeting other than those matters that relate to the election, removal or replacement of directors. As of the Record Date, there were 155,037,431145,826,079 shares of our Class A common stock and 100zero shares of our Class B common stock outstanding. We refer to our Class A common stock and our Class B common stock collectively as our common stock. Stockholders do not have cumulative voting rights for the election of directors.

Stockholders of record; shares registered in your name

If shares of our common stock are registered directly in your name with our transfer agent, Equiniti Trust Company, you are considered the stockholder of record with respect to those shares, and the Notice was provided to you directly by us. As the stockholder of record, you have the right to grant your voting proxy and indicate your voting choices directly to the individuals listed on the proxy card or to vote virtually at the Annual Meeting. Throughout this proxy statement, we refer to these registered stockholders as “stockholders of record.”

Street name stockholders

If shares of our common stock are held on your behalf in a brokerage account or by a bank or other nominee, you are considered to be the beneficial owner of shares that are held in “street name,” and the Notice was forwarded to you by your broker, bank or other nominee, who is considered the stockholder of record with respect to those shares. As the beneficial owner, you have the right to direct your broker, bank or other nominee as to how to vote your shares in the manner provided in the voting instructions you receive from your broker, bank or other nominee. If you request a printed copy of our proxy materials by mail, your broker, bank or other nominee will provide a voting instruction form for you to use. Street name

stockholders are also invited to attend the virtual Annual Meeting. However, because a street name stockholder is not the stockholder of record, you may not vote your shares of our common stock virtually at the Annual Meeting unless you follow your broker, bank or other nominee’s procedures for obtaining a legal proxy. Throughout this proxy statement, we refer to stockholders who hold their shares through a broker, bank or other nominee as “street name stockholders.”

How many votes are needed for approval of each proposal?

Voting results will be tabulated and certified by the inspector of election appointed for the Annual Meeting.

What is a quorum?

A quorum is the minimum number of shares required to be present at the Annual Meeting to properly hold an annual meeting and conduct business under our bylaws and Delaware law. The presence in person or represented by proxy of the holders of a majority of the voting power of the shares of stock issued and outstanding and entitled to vote on a matter at the Annual Meeting will constitute a quorum for that matter at the Annual Meeting. Where a separate vote by a class or classes is required for any matter, the holders of a majority of the outstanding shares of such class or classes, present in person or represented by proxy, shall constitute a quorum to take action with respect to that vote on that matter. Proposal No. 5 requires a separate vote by the holders of our Class A common stock. Abstentions and broker non-votes are counted as shares present and entitled to vote for purposes of determining a quorum.

How do I vote?

If you are a stockholder of record, there are fivefour ways to vote:

VOTING VIA THE INTERNET OR BY TELEPHONE IS FAST AND CONVENIENT, AND YOUR VOTE IS IMMEDIATELY CONFIRMED AND TABULATED. VOTING EARLY WILL HELP AVOID ADDITIONAL SOLICITATION COSTS AND WILL NOT PREVENT YOU FROM VOTING ELECTRONICALLY DURING THE ANNUAL MEETING IF YOU WISH TO DO SO.

If you are a street name stockholder, you will receive voting instructions from your broker, bank or other nominee. You must follow the voting instructions provided by your broker, bank or other nominee in order to direct your broker, bank or other nominee on how to vote your shares. As discussed above, if you are a street name stockholder, you may not vote your shares electronically at the Annual Meeting unless you obtain a legal proxy from your broker, bank or other nominee.

Can I change my vote?

Yes. If you are a stockholder of record, you can change your vote or revoke your proxy any time by:

If you are a street name stockholder, your broker, bank or other nominee can provide you with instructions on how to change your vote.

What is the effect of giving a proxy?

Proxies are solicited by and on behalf of our board of directors. Jesse Singh (our President and Chief Executive Officer), Peter Clifford (our Chief FinancialOperations Officer and Treasurer)Chief Financial Officer) and Paul KardishMorgan Walbridge (our Chief Legal Officer and Secretary) have been designated as proxy holders by our board of directors. When proxies are properly dated, executed and returned, the shares represented by such proxies will be voted at the Annual Meeting in accordance with the instructions of the stockholder. If no specific instructions are given, however, the shares will be voted in accordance with the recommendations of our board of directors as described above. If any matters not described in this proxy statement are properly presented at the Annual Meeting, the proxy holders will use their own judgment to determine how to vote the shares. If the Annual Meeting is postponed, adjourned or continued, the proxy holders can vote the shares on the new Annual Meeting date as well, unless you have properly revoked your proxy instructions, as described above.

Why did I receive a Notice of Internet Availability of ProxyProxy Materials instead of a full set of proxy materials?

In accordance with the rules of the U.S. Securities and Exchange Commission, or the SEC, we have elected to furnish our proxy materials, including this proxy statement and our 20212023 Annual Report, primarily via the Internet. The Notice containing instructions on how to access this proxy statement and our 20212023 Annual Report is first being mailed on or about January 26, 202218, 2024 to all stockholders entitled to vote at the Annual Meeting. Stockholders may request to receive all future proxy materials in printed form by mail or electronically by email by following the instructions contained in the Notice. We encourage stockholders to take advantage of the availability of our proxy materials on the Internet to help reduce the environmental impact and the cost of our annual meetings of stockholders.

How are proxies solicited for the Annual Meeting?

Our board of directors is soliciting proxies for use at the Annual Meeting. All expenses associated with this solicitation will be borne by us. We will reimburse brokers, banks and other nominees for reasonable expenses that they incur in sending our proxy materials to you if a broker, bank or other nominee holds shares of our common stock on your behalf. In addition, our directors and employees may also solicit proxies in person, by telephone, or by other means of communication. Our directors and employees will not be paid any additional compensation for soliciting proxies. We have also retained D.F. King & Co. to solicit proxies for a fee of $15,000$13,500 plus a reasonable amount to cover expenses.

How may my broker, bank or other nominee vote my shares if I fail to provide timely directions?

Brokers, banks and other nominees holding shares of our common stock in street name for their customers are generally required to vote such shares in the manner directed by their customers. In the absence of timely directions, your broker, bank or other nominee will have discretion to vote your shares on our sole “routine” matter: the proposal to ratify the appointment of PricewaterhouseCoopers LLP, or PwC as our independent registered public accounting firm for our year ending September 30, 2022.2024. Your broker, bank or other nominee will not have discretion to vote on the election of directors or the frequency with which we will hold Say-on-Pay Votes, the approval of amendments tothe compensation of our certificate of incorporation, or our Certificate, and bylaws or our adoption of the 2021 Employee Stock Purchase Plan, allnamed executive officers, each of which areis a “non-routine” matters,matter, absent direction from you. If the broker, bank or other nominee that holds your shares in street name returns a proxy card without voting on a non-routine proposal because it did not receive voting instructions from you on that proposal, this is referred to as a “broker non-vote.” Broker non-votes are considered in determining whether a quorum exists at the Annual Meeting. The effect of broker non-votes on the outcome of each proposal to be voted on at the Annual Meeting is explained above.

Where can I find the voting results of the Annual Meeting?

We will announce preliminary voting results at the Annual Meeting. We will also disclose voting results on a Current Report on Form 8-K that we will file with the SEC within four business days after the Annual Meeting. If final voting results are not available to us in time to file a Current Report on Form 8-K within four business days after the Annual Meeting, we will file a Current Report on Form 8-K to publish preliminary results and will provide the final results in an amendment to the Current Report on Form 8-K as soon as they become available.

I share an address with another stockholder, and we received only one paper copy of the proxy materials. How may I obtain anadditional copy of theproxy materials?

The rules promulgated by the SEC permit companies, brokers, banks or other intermediaries to deliver a single copy of proxy materials, or, where applicable, a Notice of Internet Availability of Proxy Materials, to households at which two or more stockholders reside. Each stockholder, however, still receives a separate proxy card if he or she receivesthey receive paper copies. This practice, known as “householding,” is designed to reduce duplicate mailings and save significant printing and postage costs as well as natural resources. Stockholders sharing an address who have been previously notified by their broker, bank or other nominee and have consented to householding will receive only one copy of our proxy statement and annual report or Notice of Internet Availability of Proxy Materials. If you would like to opt out of this practice for future mailings and receive a separate proxy statement and annual report or Notice of Internet Availability of Proxy Materials for each stockholder sharing the same address, please contact your broker, bank or other nominee.

You may also obtain a separate proxy statement or annual report or Notice of Internet Availability of Proxy Materials without charge by sending a written request to Broadridge Householding Department, 51 Mercedes Way, Edgewood, New York 11717, or by calling Broadridge’s Householding Department at 1-866-540-7095. We encourage stockholders to contact us by telephone instead of physical mail to help ensure timely receipt of any request for proxy materials. Additional copies of the proxy statement or annual report or Notice of Internet Availability of Proxy Materials will be sent promptly upon receipt of such request. Stockholders sharing an address that are receiving multiple copies of the proxy statement or annual report or Notice of Internet Availability of Proxy Materials can request delivery of a single copy of the proxy statement or annual report or Notice of Internet Availability of Proxy Materials by contacting their broker, bank or other nominee or sending a written request to Broadridge Householding Department at the address above or by calling 1-866-540-7095.

What is the deadline to propose stockholder actions and director nominationsnominations for consideration at next year’s annual meeting ofstockholders?

RULE 14A-8 STOCKHOLDER PROPOSALS

As prescribed by Rule 14a-8 under the Securities Exchange Act of 1934, as amended, or the Exchange Act, stockholders may present proper proposals for inclusion in our proxy statement and for consideration at next year’s annual meeting of stockholders. For a Rule 14a-8 stockholder proposal to be timely and considered for inclusion in our proxy statement for our 20232025 annual meeting of stockholders, the proposal must comply with all applicable requirements of Rule 14a-8, including with respect to ownership of our common stock, and our Corporate Secretary must receive the written proposal at our principal executive offices by the deadline prescribed by Rule 14a-8 under the Exchange Act (provided that the 20232025 annual meeting of stockholders is not held more than 30 days from the first anniversary of the Annual Meeting, the applicable deadline will be September 26, 2022)20, 2024). Stockholder proposals should be addressed to:

The AZEK Company Inc.

Attention: Corporate Secretary

1330 W Fulton Street #350

Chicago, Illinois 60607

If a stockholder who has notified us of his, her or its intention to present a Rule 14a-8 stockholder proposal at an annual meeting does not appear and a qualified representative of that stockholder does not appear to present his, her or its proposal at such annual meeting, such proposal shall be disregarded and we are not required to present the proposal for a vote at such annual meeting.

ADVANCE NOTICE STOCKHOLDER PROPOSALS

Our bylaws also establish an advance notice procedure for stockholders who wish to present a proper proposal, including director nominations, before an annual meeting of stockholders (regardless of whether the proposal is intended to be included in our proxy statement). Any such advance notice stockholder proposal, including director nominations, must comply with all of the requirements set forth in our Certificate, our bylaws and applicable laws, rules and regulations. Our bylaws provide that, for business to be properly brought before an annual meeting by a stockholder, (i) the stockholder must be a stockholder of record at the time of the giving of the notice and at the time of the annual meeting, (ii) the stockholder is entitled to vote at the meeting, (iii) the business must be a proper matter for stockholder action, and (iv) the stockholder must give timely written notice to our Corporate Secretary, which notice must contain the information specified in our bylaws. For an advance notice stockholder proposal, including director nominations, to be timely for our 20232025 annual meeting of stockholders, our Corporate Secretary must receive the written proposal at our principal executive offices at the address listed above:

In the event that we hold our 20232025 annual meeting of stockholders more than 30 days before or more than 60 days after the one-year anniversary of the Annual Meeting, notice of an advance notice stockholder proposal must be received no earlier than the close of business on the 120th day before our 20232025 annual meeting of stockholders and no later than the close of business on the later of the following two dates:

If a stockholder who has notified us of his, her or its intention to present an advance notice stockholder proposal, including director nominations, at an annual meeting does not appear and a qualified representative of that stockholder does not appear to present his, her or its proposal at such annual meeting, such proposal shall be disregarded and we are not required to present the proposal for a vote at such annual meeting.

You are advised to review our bylaws, which contain additional requirements regarding advance notice stockholder proposals, including director nominations.

RULE 14A-19 STOCKHOLDER PROPOSALS

To comply with the universal proxy rules, stockholders who intend to solicit in support of director nominees other than our nominees must comply with the advance notice procedures set forth in our bylaws and described above and provide a notice that sets forth the information required by Rule 14a-19 under the Exchange Act by no later than December 31, 2024. However, note that this date does not supersede any of the requirements or timing required by our bylaws.

Availability of amended and restated bylaws

A copy of our amended and restated bylaws is available via the SEC’s website at https://www.sec.gov. You may also contact our Corporate Secretary at the address set forth above for a copy of the relevant bylaw provisions regarding the requirements for making stockholder proposals and nominating director candidates.

BOARD OF DIRECTORS

Board of Directors Composition

We are managed under the direction of our board of directors, which is currently composed of eleveneight members. All of our directors, with the exception ofincluding our new director nominee, Fiona Tan, but excluding our Chief Executive Officer, are independent within the meaning of the listing standards of the New York Stock Exchange, or the NYSE.

Our Certificate currently provides for a board of directors comprised of three classes of directors, with each class serving a three-year term beginning and ending in different years than thosedirectors. Our Certificate also provides for the phasing out of the other two classes. Subjectclassification of our board of directors. Our directors to the outcome of the vote at the 2022 Annual Meeting with respect to Proposal No. 5, only one class of directors will be elected at the Annual Meeting shall each annual meeting ofserve a one-year term. Beginning with our stockholders, with the other classes continuing for the remainder of their respective three-year terms. Our board of directors is currently divided among the three classes as follows:

For more information regarding Proposal No. 5, which, if successful, would authorize us to amend our Certificate and bylaws to phase out our classified board structure, please see “PROPOSAL NO. 5— Approval of Amendments to our Certificate of Incorporation to Declassify our Board of Directors and Phase-In Annual Director Elections”.one-year terms.

Director Term and Committee Membership Information

The following table sets forth the names, ages as of January 14, 2022,17, 2024, and certain other information for each of the members of our board of directors with terms expiring at the Annual Meeting (who are also nominees for election as a director at the Annual Meeting), for our new director nominee and for each of the continuing membersmember of our board of directors. Full biographical information follows the table.

Legend: (C) ChairpersonChair of the Board |  Chair |  Member |   Audit Committee Financial Expert

(1) Ms. Tan's committee appointments, if any, will be determined following her election at the Annual Meeting.

Nominees for Director

Continuing Directors

Continuing Director

PROPOSAL NO. 1

ELECTION OF DIRECTORS

Our board of directors is currently composed of eleveneight members. In accordance with our Certificate, as currently in effect, our board of directors is divided into three classes of directors. At the Annual Meeting, two Class II directors will be elected for a three-year term to succeed the Class II directors whose term is then expiring. Mr. Sumler, a Class II director, is not standing for re-election. Each director’s term continues until the election and qualificationThe classification of his or her successor, or such director’s earlier death, resignation, disqualification or removal. At the 2022 Annual Meeting, we are seeking stockholder approval to declassify our board of directors is currently being phased out, such that, beginning with our 2025 annual meeting of stockholders, the declassification of our board of directors will be complete and phase-in theall directors will be subject to annual election for one-year terms. There are seven directors with terms of alloffice expiring at our Annual Meeting.

At the recommendation of our nominating and governance committee, our board of directors has nominated eight candidates for election as described under “Proposal No. 5”.directors at the Annual Meeting. In connection with the nominations, our board of directors has approved an increase in the size of the board of directors from eight to nine members, which increase in the size of the board is conditioned on and only effective in the event that our new director nominee, Fiona Tan is affirmatively elected as a director at the Annual Meeting. In the event our new director nominee, Fiona Tan, is not elected, the size of the board of directors will remain at eight directors.

Nominees

Our nominating and corporate governance committee has recommended, and our board of directors has approved, Fumbi ChimaGary Hendrickson, Sallie B. Bailey, Pamela Edwards, Howard Heckes, Vernon J. Nagel, Harmit Singh, Jesse Singh and Brian SpalyFiona Tan as nominees for election as Class II directors at the Annual Meeting. If elected, each of Ms. Chima and Mr. Spalythem will serve as Class II directors until our 2025 annual meeting of stockholders and until their successors are duly elected and qualified, or until their earlier death, resignation, disqualification or removal. Each of the nominees, other than Fiona Tan, is currently a directorcurrent member of our board of directors. Pamela Edwards and Harmit Singh were appointed by the board of directors effective September 14, 2023, and are each subject to reappointment by our stockholders at the Annual Meeting. In addition, in connection with our continued efforts to enhance the composition our board of directors, the board of directors has nominated Fiona Tan for appointment by the stockholders of the Company and has agreed to serve if elected.at the Annual Meeting. For information concerning the nominees, please see “Board of Directors—Nominees for Director.”

If you are a stockholder of record and you sign your proxy card or vote by telephone or over the Internet but do not give instructions with respect to the voting of directors, your shares will be voted “FOR” the election of each of Ms. ChimaMessrs. Hendrickson, Heckes, Nagel, H. Singh and Mr. Spaly.J. Singh and Mses. Bailey, Edwards and Tan. We expect that each of Ms. Chima and Mr. Spalythem will accept such nomination; however, in the event that a director nominee is unable or declines to serve as a director at the time of the Annual Meeting, the proxies will be voted for any nominee designated by our board of directors to fill such vacancy.vacancy; provided, however, that in the event that Ms. Tan is not appointed as a director at the Annual Meeting, the size of the board of directors will remain at eight directors and there will not be a vacancy with respect to the position on the board of directors that would have been filled by Ms. Tan. If you are a street name stockholder and you do not give voting instructions to your broker, bank or other nominee, your broker, bank or other nominee will not vote your shares on this matter.

Vote Required; Recommendation of the Board of Directors

Our bylaws state that, to be elected, a nominee must receive a plurality of the votes of the shares present in person or represented by proxy and entitled to vote on the election of directors at the Annual Meeting, which means that the individuals who receive the largest number of votes cast “FOR” are elected as directors. As a result, any shares not voted “FOR” a particular nominee (whether as a result of stockholder abstention or a broker non-vote) will have no effect on the outcome of this proposal. Brokers do not have authority to vote on this proposal without instructions from the beneficial owner.

THE BOARD OF DIRECTORS UNANIMOUSLY RECOMMENDS THAT THE STOCKHOLDERS VOTE “FOR” THE ELECTION OF EACH OF FUMBI CHIMAGARY HENDRICKSON, SALLIE B. BAILEY, PAMELA EDWARDS, HOWARD HECKES, VERNON J. NAGEL, HARMIT SINGH, JESSE SINGH AND BRIAN SPALYFIONA TAN TO THE BOARD FOR A THREE-YEARONE-YEAR TERM EXPIRING IN 2025.

CORPORATE GOVERNANCE

Corporate Governance Overview and Fiscal 2021 Highlights

We are committed to operating with integrity and accountability. Our corporate governance policies set clear expectations and responsibilities for our board of directors, leaders, employees and business partners to ensure we conduct our operations in a manner that is consistent with the highest standards of business ethics and accountability. Highlights of our corporateCorporate governance practiceshighlights include the following:

Commitment to Sustainability and Corporate Responsibility

We are committed to having a positive and lasting impact on the world and, as both a recycler and consumer of hundreds of millions of pounds of otherwise landfill-bound waste and scrap each year, our commitment to ESG stewardship is fundamental to the products and innovations we bring to market. By focusing on what positively impacts our products, people and planet the most, our ESG strategy, which we call our FULL-CIRCLE™ ESG strategy, fuels AZEK’s growth and profitability. It future proofs our business, enables us to attract and engage employees, customers, suppliers, investors and other key stakeholders, and positions us for long-term success and shared value creation.

In alignment with our core value of always striving to be better today than yesterday, we are committed to building on our strengths and improving how we measure and monitor our progress on our ESG-related initiatives. Our board of directors oversees ESG matters, including corporate social responsibility and sustainability initiatives, including ESG-related strategies, policies and disclosures, seedisclosures. See “Role of the Board in ESG Oversight” below. Fiscal 2021 ESG highlights includeWe believe the following:following further highlight our commitment to sustainability and corporate responsibility:

Human Capital and Diversity, Equity and Inclusion

We are committed to social responsibility within our workforce and believe that cultivating a diverse and inclusive workplace provides for a broad array of viewpoints, talents and skills that drive operational excellence and build a more inclusive future. Our culture is comprised of innovative, growth-minded individuals committed to always doing the right thing, continuous improvement and solving problems for our customers and partners. We believe the following further highlight our commitment to social responsibility within our workforce:

Role of the Board in ESG Oversight

The Board of Directors is responsible for overseeing the Company’s strategic direction, including the integration of ESG risks and opportunities into the Company’s strategy. Each Board committee also plays an important role in overseeing aspects of ESG, and provides regular updates to the full Board on its areas of ESG oversight responsibility. The Board, taking into account these reports, monitors ESG-related risks and opportunities as part of its overarching risk management and strategy responsibilities. At the management level, we have also established an ESG Steering Committee consisting of leaders from across our organization. The ESG Steering Committee generally meets monthly and is responsible for oversight of the day-to-day management of ESG matters, as well as formulating strategies for achieving ESG targets and tracking performance to completion. In addition, our Vice President of ESG responsible for continuingoversees our day-to-day initiatives and execution and reports directly to drive our company-wideCEO on these matters. All levels of the organization support the board of directors with its oversight of our ESG strategy and related initiatives.strategy.