Limbach Holdings, Inc. (the “Company,” “we” or “us”), a Delaware corporation headquartered in Warrendale, Pennsylvania, was formed on July 20, 2016 as a result of a business combination with Limbach Holdings LLC (“LHLLC”). The Company is a building systems solutionssolution firm that partners with expertise in the design, prefabrication, installation, managementbuilding owners and maintenance of heating,facilities managers who have mission critical mechanical (heating, ventilation, air-conditioning (“HVAC”)air conditioning), mechanical, electrical, and plumbing and controls systems.infrastructure. The Company provides comprehensive facilitystrives to be an indispensable partner to its customers by providing services consistingthat are essential to the operation of mechanical construction, full HVAC service and maintenance, energy audits and retrofits, engineering and design build services, constructability evaluation, equipment and materials selection, offsite/prefabrication construction, and the complete range of sustainable building solutions.their businesses. The Company partnersworks with institutions with mission-critical infrastructures, such as data centers andbuilding owners primarily in six vertical markets: healthcare, industrial and light manufacturing, cultural and entertainment,data centers, life science, higher education and life science facilities.cultural and entertainment. The Company operates primarilyhas more than 1,400 team members in 19 offices across the Northeast, Mid-Atlantic, Southeasteastern United States. The Company’s team members uniquely combine engineering expertise with field installation skills to provide custom solutions that leverage its full life-cycle capabilities, which allows it to address both the operational and Midwest regionscapital projects needs of its customers.

Segments

The Company operates in two segments, (i) General Contractor Relationships (“GCR”), in which the Company generally manages new construction or renovation projects that involve primarily HVAC,mechanical, plumbing, or electrical services awarded to the Company by general contractors or construction managers, and (ii) Owner Direct Relationships (“ODR”), in which the Company performs owner direct construction projects and/or provides maintenance or services primarily on HVAC,mechanical, plumbing or electrical systems, building controls and specialty contracting projects direct to, or assigned by, building owners or property managers. This work is primarily performed under fixed price, modified fixed price, and time and material contracts over periods of typically less than two years.

maintenance services, which it believes improves revenue predictability and could increase economic resilience. The Company provides its ODR business services through both a variety of project delivery methodologies and other service and technical offerings:

The Company continues to expand its owner-direct offerings to include other digital solutions to manage and monitor the performance of building systems, including data analytics, energy consumption and sustainability. These services allow the Company to develop new revenue streams, leveraging its professional services capabilities to support multi-location regional and national customers in core end-markets, and to drive energy retrofit and performance optimization projects for building owners.

The Company also partners with building owners in other market sectors (infrastructure, government, hospitality and commercial). It is imperative that the partnerships formed between the Company and its building owners share in similar core values.

benefits packages and excellent advancement opportunities. The Company invests in its employees through safety and wellness programs, internal communication, career development training programs, recognition programs and succession planning initiatives.

GCR and ODR Backlog

The Company’s GCR backlog was $302.9$186.9 million and $337.2$302.9 million as of December 31, 20222023 and 2021,2022, respectively. Projects are brought into backlog once the Company has been provided with a written confirmation of award and the contract value has been established. At any point, in time, the Company has a substantial volume of projects that are specifically identified and advanced in negotiations and/or documentation, however those projects are not booked as backlog until the Company has received written confirmation from the owner or the GC/CMgeneral contractor / construction manager of their intention to award it the contract and they have directed the Company to begin engineering, designing, incurring construction labor costs or procuring needed equipment and material. The Company’s GCR projects tend to be built over a 12- to 24-month schedule depending upon scope and complexity. Most major projects have a preconstruction planning phase which may require months of planning before actual construction commences. The Company is occasionally employed to deliver a “fast-track” project, where construction commences as the preconstruction planning work continues. As work on the Company’s projects progress, it increases or decreases backlog to take into account its estimate of the effects of changes in estimated quantities, changes in conditions, change orders and other variations from initially anticipated contract revenue, and the percentage of completion of the Company’s work on the projects. Based on historical trends, the Company currently estimates that 68%83% of its GCR backlog as of December 31, 20222023 will be recognized as revenue during 2023.2024. Additionally, the reduction in GCR backlog has been intentional as the Company lookscontinues to focus on higher margin projects than historically, as well as its focus on smaller, higher margin owner direct projects.

The Company’s ODR backlog was $108.2$147.0 million and $98.0$108.2 million as of December 31, 20222023 and 2021,2022, respectively. These amounts reflect unrecognized revenue expected to be recognized over the remaining terms of ourthe Company’s service contracts and projects.

Competition

The HVAC,mechanical, plumbing, electrical, and maintenance industry is highly competitive and the geographic markets in which the Company competes has numerous companies that provide similar services. Factors influencing the Company’s competitiveness include price, reputation for quality, ability to reduce customer costs, experience and expertise, financial strength, surety bonding capacity, knowledge of local markets and conditions, availability and experience of craft labor, and customer

relationships. Competitors tend to be regional firms that vary in size and depth of resources. There are, however, significant national competitors that have greater national presence and breadth of expertise than the Company does.Company.

Materials &and Equipment

Human Capital

To ensure that the Company is well positioned to provide innovative system solutions and reliable services in a safe, efficient and responsible manner, the Company seeks to employ and retain a team of highly dedicated and accomplished people who genuinely care about the success of the Company. Creating an engaging workplace environment that provides for competitive

The Company’s culture is driven by its Core Values:

The Company offers its employees the opportunity to join ERGs. These groups foster professional development, social connectivity, and celebrate diversity throughout the Company. Each year, new ERGs are evaluated for consideration. Currently, there are twofour active ERGs at the Company:

In addition, to help recruit the next generation of diverse industry leaders, the Company is actively involved with the ACE Mentor Program of America, Inc. (“ACE”). ACE helps mentor high school students and inspires them to pursue careers in design and construction. It is the construction industry’s fastest-growing high school mentoring program, reaching over 8,000 students annually.

As such, the Company has committed itself to the health, safety and well-being of its workers and their families. One of the ways the Company shows its commitment is through offering competitive employee compensation and benefits packages, specifically designed to meet the unique needs of each individual in its organization, which include:

This program helped earn the Company’s Ohio business unit the highest honor for which Occupational Safety and Health Administration (“OSHA”) can name a company; OSHA-Voluntary Protection Programs Star Site. This was the first time a union mechanical contractor has earned such an honor in the United States. The Company strives to achieve this honor at its other business units.

Severe weather can impact the Company’s operations. In the northern climates where it operates, and to a lesser extent the southern climates as well, severe winters can slow the Company’s productivity on construction projects, which shifts revenue and gross profit recognition to a later period. The Company’s maintenance operations may also be impacted by mild or severe weather. Mild weather tends to reduce demand for the Company’s maintenance services, whereas severe weather may increase the demand for its maintenance and time-and-materials services.

The Company is subject to various federal, state and local laws and regulations relating to the environment, including those relating to discharges to air, water and land, the handling and disposal of solid and hazardous waste, the handling of underground storage tanks and the cleanup of properties affected by hazardous substances. The Company also is subject to

compliance with numerous other laws and regulations of federal, state, local agencies, and authorities, including those relating to workplace safety, wage and hour, and other labor issues (including the requirements of the Occupational Safety and Health Act and comparable state laws), immigration controls, vehicle and equipment operations and other aspects of its business. In addition, a relatively limited number of the Company’s construction contracts are entered into with public authorities, and these contracts frequently impose additional requirements, including requirements regarding labor relations and subcontracting with designated classes of disadvantaged businesses. A large portion of the Company’s business uses labor that is provided under collective bargaining agreements. As such, the Company is subject to federal laws and regulations related to unionized labor and collective bargaining (including the National Labor Relations Act).

The Company continually monitors its compliance with these laws, regulations and other requirements. While compliance with existing laws, regulations and other requirements has not materially adversely affected the Company’s operations in the past,

Climate Change and Sustainability

The Company recognizes its environmental and societal responsibilities and is committed to sustainability and to improving its environmental footprint as well as operating its business in a manner that seeks to protect the health and safety of the Company’s employees and customers, as well as the public. The Company’s focus on environmental stewardship and improving productivity drives not only its efforts to become more energy efficient but also improvements in the Company’s customers'customers’ impact on climate change. Replacing an aging building’s existing systems with modern, energy-efficient systems significantly reduces a building’s energy consumption and carbon footprint while improving cost, air quality and overall system effectiveness.

The Company is subject to the requirements of numerous federal, state and local laws, regulations and rules that promote the protection of the environment. While capital expenditures or operating costs for environmental compliance cannot be predicted with certainty, the Company does not currently anticipate that they will have a material effect on its capital expenditures or competitive position in the short term.

Available Information

The Company’s internet address is https://www.limbachinc.com. The Company makes available, free of charge, on its Internet website copies of the Company’s annual report on Form 10-K, quarterly reports on Form 10-Q, current reports on Form 8-K, and amendments to those reports as soon as reasonably practicable after the Company electronically files such material with, or furnishes it to, the SEC.United States Securities and Exchange Commission (the “SEC”).

The content of the Company’s website is not incorporated by reference into this annual report on Form 10-K or in any other report or document it files with the SEC, and any references to the Company’s website is intended to be inactive textual references only.

Risks Related to Our Business and Industry

The markets we serve are highly fragmented and competitive. The non-residential contracting industry is characterized by numerous companies, many of which are small and whose activities are often geographically concentrated. We compete on the basis of our technical expertise and experience, financial and operational resources, industry reputation and dependability. While we believe our customers consider a number of these factors in awarding available contracts, price is often the principal factor in determining which contractor is selected, especially on smaller, less complex projects. As such, smaller competitors are sometimes able to win bids for such projects based on price alone due to their lower cost and financial return requirements. We expect competition to remain intense for the foreseeable future, presenting us with significant challenges in our ability to

The growth we have experienced in the past, and that we may experience in the future, may provide challenges to our organization, requiring us to expand our personnel and operations. Future growth, whether organic or through acquisitions, may strain our infrastructure, operations and other managerial and operating resources. We have also experienced severe constriction in the markets in which we operated in the past and, as a result, in our operating requirements. Failing to maintain the appropriate cost structure for a particular economic cycle may result in us incurring costs that affect our profitability. If our business resources become strained or overly-burdensome, our earnings may be adversely affected and we may be unable to increase revenue growth. Further, we may undertake contractual commitments that exceed our labor resources, which could also adversely affect our earnings and ability to increase revenue growth.

Due to the size and nature of our regional construction contracts, one or a few customers have in the past, and may in the future, represent a substantial portion of our consolidated revenue and gross profits in any one year or over a period of several consecutive years. For example, for the year ended December 31, 2022, one GCR segment customer accounted for approximately 11% of consolidated total revenue. For the year ended December 31, 2021, two GCR segment customers accounted for approximately 17% and 12% of consolidated total revenue, respectively. Similarly, our backlog frequently reflects multiple contracts for a limited number of customers; therefore, one customer may comprise a significant percentage of backlog at a certain point in time. The loss of business from any one of such customers could have a material adverse effect on our business or results of operations; however, our customer base continues to shift to a more ODR-centric direction, which typically yield projects that are of less risk and smaller in nature. Also, a default or delay in payment on a significant scale by a customer may have a material adverse effect on our financial position, results of operations and cash flows.

We cannot guarantee that the revenue projected in our contract backlog will be realized or, if realized, will be profitable. Projects reflected in the contract backlog may be affected by project cancellations, scope adjustments, time extensions or other changes. Such changes may materially and adversely affect the revenue and profit we ultimately realize on these projects.

Our contract prices are established largely upon estimates and assumptions of our projected costs, including assumptions about future economic conditions; prices, including commodities prices; availability of labor; the costs of providing labor, equipment, and materials; and other factors outside of our control. If our estimates or assumptions prove to be inaccurate, due to changing circumstances or our failure to successfully execute the work, cost overruns may occur and we could experience reduced profits

or a loss for affected projects. For instance, unanticipated technical problems may arise; we could have difficulty obtaining permits or approvals; local laws, labor costs or labor conditions could change; bad weather could delay construction; prices of raw materials could increase; suppliers or subcontractors may fail to perform as expected; or site conditions may be different than originally anticipated. We are also exposed to increases in energy prices. Additionally, in certain circumstances, we guarantee project completion or the achievement of certain acceptance and performance testing levels by a scheduled date. Failure to meet schedule or performance requirements typically results in additional costs to us, and in some cases may also create liability for consequential and liquidated damages. Performance problems for existing and future projects could also cause our actual results of operations to differ materially from those anticipated and could damage our reputation within the industry and our customer base.

In addition, the costs incurred and gross profit realized on our contracts can vary, sometimes substantially, from our original projections due to a variety of factors, including, but not limited to:

Many of our customer contracts contain provisions that purport to shift some or all of the above risks from the customer to us, even in cases where the customer is partly at fault. We are not always able to shift this risk to subcontractors. Our experience has been that customers are willing to negotiate equitable adjustments in the contract compensation or completion time provisions if unexpected circumstances arise. However, customers may seek to impose contractual risk-shifting provisions more aggressively, which could increase risks and adversely affect our financial position, results of operations and cash flows.

The timing of project awards is unpredictable and outside of our control. Project awards often involve complex and lengthy negotiations and competitive bidding processes. These processes can be impacted by a wide variety of factors, including a customer’s decision to not proceed with the development of a project, governmental approvals, financing contingencies, commodity prices, environmental conditions, and overall market and economic conditions. We may not win contracts that we have bid upon for any number of reasons, including price, a customer’s perception of our ability to perform, a competitor’s relationships and/or perceived technology advantages held by others. Many of our competitors may be more inclined to take greater or unusual risks or accept terms and conditions in a contract that we might not deem acceptable. Because a significant portion of our revenue is generated from large projects, our results of operations can fluctuate quarterly and annually depending on whether, and when, large project awards occur, as well as the commencement and progress of work under large contracts already awarded. As a result, we are subject to the risk of losing new awards to competitors or the risk that revenue may not be derived from awarded projects as quickly as anticipated.

The uncertainty of the timing of project awards may also present difficulties in matching the size of our work crews with project needs. In some cases, we may maintain and bear the cost of more ready work crews than are currently required in anticipation

In addition, the timing of the revenue, earnings and cash flows from our contracts in backlog could be delayed by a number of factors, including adverse weather conditions; other subcontractors delaying the progression of proceeding work; delays in receiving material and equipment from suppliers and services from subcontractors; and changes in the scope of work to be performed. Such delays, if they occur, could have material and adverse effects on our operating results for current and future periods until the affected contracts are completed.

After the award of a contract, we may perform additional work that was not contemplated in our original contract price, at the request or direction of the customer, without the benefit of an approved change order. Our contracts generally afford the customer the right to order such changed or additional work, and typically require the customer to compensate us for the additional work. If we are unable to successfully negotiate a change order, or fail to obtain adequate compensation for these matters, we could be required to record in the current period an adjustment to revenue and profit recognized in prior periods. Such adjustments, if substantial, could have a material adverse effect on our financial position, results of operations and cash flows.

In certain circumstances, we assert or have asserted claims against project contractors, owners, engineers, consultants, subcontractors or others involved in a project for additional costs exceeding the contract price or for amounts not included in the original contract price. These types of claims occur due to matters such as delays, inefficiencies or errors caused by others or changes from the initial project scope, all of which may result in additional costs. Often, these claims can be the subject of lengthy negotiations, arbitration or even litigation proceedings, and it is difficult to accurately predict when and on what terms these claims will be ultimately resolved.

The potential impact of recoveries for claims may be material in future periods when they, or a portion of them, become probable and estimable or are settled and therefore these claims have the ability to negatively impact our results of operations and financial condition. For example, we could have estimated and reported a profit on a contract over several periods and later determined, that all or a portion of such previously estimated and reported profits were overstated due to the results of the settlement of a claim. If this occurs, the full aggregate amount of the overstatement would be reported for the period in which such determination is made, thereby offsetting all or a portion of any profits from other contracts that would be reported in such period, or even resulting in a loss being reported for such period. On a historical basis and in accordance with generally accepted accounting principles in the United States of America, we have used a detailed process in estimating and accounting for these claims and we believe that we have typically made reliable estimates of such claims. However, given the uncertainties associated with these types of claims, it is possible for actual recoveries to materially and adversely vary from estimates previously made, which may result in reductions or reversals of previously recorded revenue and profits. We could also recognize additional revenue and profits when the final settlements exceed our recorded estimates.

In addition, when these types of claims are made, we may use or have used working capital to cover cost overruns pending the resolution of the relevant claims and may incur additional costs when pursuing such potential recoveries. A failure to recover on these types of claims promptly and fully could have a negative impact on our financial position, results of operations, cash

flows and liquidity. Moreover, our use of working capital to cover cost overruns related to pending claims may impact our ability to meet our credit agreement covenants or limit the use of our credit agreements. If we default under our credit agreements, it could result in, among other things, us no longer being entitled to borrow under one or more of the credit agreements, acceleration of the maturity of outstanding indebtedness under the agreements, foreclosure on collateral securing the obligations under the agreements or require us to enter into amendments and/or waivers to those credit agreements that may place additional requirements on us and that cost us additional amounts payable to our lenders.

We operate from various locations across the eastern United States, supported by corporate executives and services, with local business unit management retaining responsibility for day-to-day operations and adherence to applicable laws. We believe that our practice of placing significant decision making powers with local management is important to our successful growth and allows us to be responsive to opportunities and to our customers’ needs. However, this practice can make it difficult to coordinate

The operating results of an individual location may differ from those of another location for a variety of reasons, including market size, local customer base, regional construction practices, competitive landscape, regulatory requirements, state and local laws and local economic conditions. As a result, certain of our locations may experience higher or lower levels of profitability and growth than other locations.

We may choose to finance future acquisitions with debt, equity, cash or a combination of the three. Future acquisitions could dilute earnings. To the extent we succeed in making acquisitions, a number of risks may result, including:

Furthermore, the costs associated with a failed acquisition or attempted acquisition transaction could have an adverse effect on our financial position, results of operations and cash flows.

Design/Build projects provide the customer with a single point of responsibility for both design and construction. When we are awarded these projects, we typically perform the design and engineering work in-house. On other projects, we are not the designer, but provide assistance directly to the project design team. In the event that a design error or omission by us causes damage, there is risk that we, our subcontractors or the respective professional liability or errors and omissions insurance would not be able to absorb the liability. Any liability resulting from an asserted design defect with respect to our projects may have a material adverse effect on our financial position, results of operations and cash flows.

Due to the nature of our contracts, we sometimes commit resources to projects prior to receiving payments from the customer in amounts sufficient to cover expenditures on projects as they are incurred. Delays in customer payments may require us to make a working capital investment. If a customer defaults in making their payments on a project to which we have devoted resources, it could have a material negative effect on our financial position, results of operations and cash flows.

Our work is conducted at offices the Company leases, as well as a variety of sites including construction sites and industrial facilities. Each location is subject to numerous health and safety risks, including electrocutions, fires, explosions, mechanical failures, exposure to hazardous materials, weather-related incidents, motor vehicle and transportation accidents and damage to equipment. In addition, we lease a sizeable fleet of vehicles operated by our employees, and many of our employees operate their personal vehicles in the course and scope of their employment, traveling to and from the sites and our facilities. These hazards can cause personal injury and loss of life, severe damage to or destruction of property and equipment and other consequential damages, and could lead to suspension of operations, large damage claims and, in extreme cases, criminal liability. While we have taken what we believe are appropriate precautions to minimize health and safety risks, we have experienced serious incidents in the past and may experience additional incidents in the future. Serious accidents may subject us to penalties, civil litigation or criminal prosecution. Claims for damages to persons, including claims for bodily injury or loss of life, could result in significant costs and liabilities, which could adversely affect our financial position, results of operations and cash flows. In addition, like other companies in our industry, we track our injury history in the form of an Experience Modification Rate (“EMR”). In the event that the EMR associated with certain of our operating units exceeds the minimum threshold set by customers, we may be unable to pursue certain projects. Poor safety performance could also jeopardize our relationships with our customers and harm our reputation.

The extent to which we utilize our workforce affects our profitability. Underutilizing our workforce could result in lower gross margins and, consequently, a decrease in our short-term profitability. On the other hand, overutilization of our workforce could negatively impact safety, employee satisfaction, attrition, and project execution, leading to a potential decline in future project awards. The utilization of our workforce is impacted by numerous factors, including:

We have separate subsidiary employers that have union and non-union operations. There is a risk that our corporate structure and operations in this regard could be challenged by one or more of the unions to which the employees belong. An adverse claim or judgment resulting from such a challenge could have a material adverse effect on our financial position, results of operations and cash flows.

We are a party to collective bargaining agreements covering a majority of our craft workforce. Although strikes, work stoppages and other labor disputes have not had a significant impact on our operations or results in the recent past, any such labor actions, or our inability to renew the collective bargaining agreements, could materially and adversely impact our financial position, results of operations and cash flows if they occur in the future.

In order to maintain and grow our business, we must make strategic decisions about our current and future business plans and effectively execute upon those plans. Our principal focus over the past few years, and a focus that we plan to continue in coming years, is the accelerated growth of our ODR segment, which includes maintenance services, small projects, building controls installation and service, building environment management and performance services, and other project opportunities performed direct for building owners. We are focused on expanding the number and breadth of owner relationships that we serve on a direct basis and to leverage these expanded owner-direct relationships to deliver a broad suite of services. We have made substantial investments to expand our ODR segment by increasing the value we can offer to service and maintenance customers. We continue to actively concentrate managerial and sales resources on training and hiring experienced employees to sell and profitably perform ODR work. With our ODR-centric focus, we’ve lessened, and continue to lessen, our resources allocated to our GCR segment and continue to limit the GCR-related work we pursue. Although we believe our ODR-centric focus addresses the needs of our business and its long-term objectives, our strategy is based on certain assumptions and forecasts, which are subject to risks and uncertainties, including whether we have accurately identified the issues, targeted the appropriate market customers, and executed our strategic efforts at the appropriate scale and scope, as well as continuing to do so. Consequently, the continued business transition to an ODR-centric focus may not be successful in yielding the intended results. Our business and financial results may be adversely impacted if we do not successfully execute our business strategy.

Our continuing success depends on the performance of our management team. We rely on the experience, efforts and abilities of these individuals, each of whom would be difficult to replace. We cannot guarantee the continued employment of any of our key executives who may choose to leave the company for any number of reasons, such as other business opportunities, differing views on strategic direction, etc. If we lose members of our management team, our business, financial position, results of operations, cash flows, and customer base, as well as the market price of our common stock, could be adversely affected.

Our business is labor intensive, and many of our operations experience a high rate of employment turnover. It is often difficult to find qualified personnel in certain geographic areas where we operate. Additionally, our business is managed by a small number of key executive and operational officers. Generally, the industry is facing a shortage of trained, skilled, and qualified management, operational, and field personnel. We may be unable to hire and retain the skilled labor force necessary to operate efficiently and to support our growth strategy or to execute our work in backlog. Changes in general or local economic conditions and the resulting impact on the labor market and on our joint venture partners, subcontractors and suppliers, may make it difficult to attract or retain qualified individuals in the geographic areas where we perform our work. Our labor

expenses may increase as a result of a shortage in the supply of skilled and other personnel. Labor shortages, increased labor costs or the loss of key personnel could reduce our profitability and negatively impact our business. Further, our relationship with some customers could suffer if we are unable to retain the employees with whom those customers primarily work and have established relationships.

Misconduct, fraud, non-compliance with applicable laws and regulations, or other improper activities by one or more of our employees, subcontractors, suppliers or partners could have a significant negative impact on our business and reputation. Examples of such misconduct include employee or subcontractor theft, the failure to comply with safety standards, state-specific laws related to automobile operations (including mobile phone usage), customer requirements, environmental laws, Disadvantaged Business Enterprises (“DBE”)DBE regulatory compliance, and any other applicable laws or regulations. While we take precautions to prevent and detect these activities, such precautions may not be effective and are subject to inherent limitations, including human error and fraud. Our failure to comply with applicable laws or regulations or acts of misconduct could subject us to fines and penalties, harm our reputation, damage relationships with customers, reduce our revenue and profits, and subject us to criminal and civil enforcement actions.

Our services often involve professional judgments regarding the planning, design, development, construction, or operations and management of complex facilities. Although we have adopted a range of insurance, risk management, and risk avoidance programs designed to reduce potential liabilities, a catastrophic event at one of our project sites or a completed project, resulting from the services we have performed, could result in significant professional or product liability and warranty or other claims against us, as well as reputational harm. These liabilities could exceed our insurance limits or impact our ability to obtain insurance in the future. Further, even where insurance coverage applies, such policies have limits and deductibles or retentions, which could result in our assumption of exposure for certain amounts with respect to any claim filed against us. In addition, customers or subcontractors who have agreed to indemnify us against any such liabilities or losses might refuse or be unable to uphold their obligations to us. An uninsured claim, either in part or in whole, as well as any claim covered by insurance but subject to a policy limit, high deductible and/or retention, could have a material adverse effect on our business, financial condition, and results of operations.

We rely heavily on third-party subcontractors to perform some, and often a majority, of the work on many of our contracts. We also rely almost exclusively on third-party suppliers to provide the equipment and materials (including pipe, sheet metal and control systems) for our contracts. If we are unable to retain qualified subcontractors or suppliers, or if our subcontractors or suppliers do not perform as anticipated for any reason, our execution and profitability could be harmed. By contract, we remain liable to our customers for the performance or failures of our subcontractors and suppliers.

We generally do not bid on projects unless we have commitments from suppliers for the materials and equipment and from subcontractors for the services required to complete the projects at prices that have been included in the bid. Thus, to the extent that we cannot obtain commitments from our suppliers for materials and equipment, and from subcontractors for services needed, or to the extent such commitments are on terms that are adverse to the Company, our ability to bid for contracts may be impaired or we may experience reduced profit or a loss on a contract. In addition, if a supplier or subcontractor is unable to deliver materials, equipment or services according to the negotiated terms of a supply/services agreement for any reason, including the deterioration of our financial condition, we may suffer delays and be required to purchase the materials, equipment and services from another source at a higher price or incur other unanticipated costs. This may reduce the profit to be realized, or result in a loss, on a contract.

We purchaseare exposed to market risks that may cause increases in the cost, or the availability of, materials, including sheet metal, steelequipment and copper piping, electrical conduit, wirecommodities utilized in our operations. We have experienced, and other various materials from numerous sources. We also purchase equipment from various manufacturers. The prices we pay formay continue to experience, delays and cost volatility of these materialsitems due to supply chain disruptions, inflationary pressures, tariffs, regulatory slowdowns and equipmentmarket disruptions. In addition, our customers’ budgets may be impacted by transportationcost increases and reduced customer spending could lead to fewer project awards and more competition. These costs may be impacted by government regulations, import duties and tariffs, changes in currency exchange rates, general economic conditions and other circumstances beyond our control. We are also exposed to

increases in energy prices, particularly as they relate to fuel prices for our fleet vehicles. Although we may attempt to pass on certain of these increased costs to our customers, we may not be able to pass all of these cost increases on to our customers. As a result, our margins may be adversely impacted by such cost increases.

Energy prices fluctuate based on events outside of our control. We could be adversely affected by limitations on fuel supplies or increases in energy prices that result in higher transportation and equipment operation costs. Although we may be able to pass through the impact of energy price charges to some of our customers, we may not be able to pass all of these cost increases on to our customers. As a result, our margins may be adversely impacted by such cost increases.

Certain of our projects include contract clauses requiring DBE participation. The participation clauses may be in the form of a goal or in the form of a minimum amount of work that must be subcontracted to a DBE firm. If we fail to complete these projects with the minimum DBE participation, we may be held responsible for breach of contract, which may include restrictions on our ability to bid on future projects, as well as monetary damages. To the extent we are responsible for monetary damages, the total costs of the project could exceed the original estimates, we could experience reduced profits or a loss for that project, and there could be a material adverse impact to our financial position, results of operations, cash flows and liquidity. Further, if we contract with a DBE contractor that is not properly qualified to perform a commercially useful function, we could be held responsible for violation of federal, state or local laws related to DBE contracting.

As part of our business, we are a party to special purpose, project specific joint venture arrangements, pursuant to which we typically jointly bid on and execute particular projects with other companies in the construction industry. Success on these joint projects depends upon the various risks discussed elsewhere in this section and on whether our joint venture partners satisfy their contractual obligations.

We and our joint venture partners are generally jointly and severally liable for all liabilities and obligations of the joint ventures. If a joint venture partner fails to perform or is financially unable to bear its portion of required capital contributions or other obligations, including liabilities stemming from lawsuits, we could be required to make additional investments, provide additional services or pay more than our proportionate share of a liability to make up for our partner’s shortfall. Furthermore, if we are unable to adequately address our partner’s performance issues, the customer may terminate the project, which could result in legal liability to us, harm to our reputation and reduction to our profit on a project. We may be the controlling member of a joint venture; however, to the extent we are not controlling, we may have limited control over certain of the decisions made by the controlling member with respect to the work being performed by the joint venture. The other member(s) may not be subject to the same compliance and regulatory requirements. While we have processes and controls intended to mitigate risks associated with our joint ventures, to the extent the controlling member makes decisions that negatively impact the joint venture it could have a material adverse effect on our financial position, results of operations, cash flow and profits.

Certain of our projects require construction surety bonds (bid, payment, and performance bonds). Historically, surety market conditions have experienced times of difficulty as a result of significant losses incurred by surety companies stemming from macroeconomic trends outside of our control. Consequently, during times when less overall bonding capacity is available in the market, surety terms have become more expensive and more restrictive. We cannot guarantee our ability to maintain a sufficient level of bonding capacity in the future, which could preclude our ability to bid for certain contracts or successfully contract with some customers. Additionally, even if we continue to be able to access bonding capacity to sufficiently bond future work, we may be required to post collateral to secure bonds, which would decrease the liquidity we would have available for other purposes. Our surety providers are under no commitment to guarantee our access to new bonds in the future; thus, our ability to access or increase bonding capacity is at the sole discretion of our surety providers. If our surety companies were to limit or eliminate our access to bonds, the alternatives would include seeking bonding capacity from other surety companies, increasing business with clients that do not require bonds and posting other forms of collateral for project performance, such as letters of credit or cash. We may be unable to secure these alternatives in a timely manner, on acceptable terms, or at all. As such, if we were to experience an interruption or reduction in the availability of bonding capacity, it is likely we would be unable to compete for or work on certain projects.

Although we maintain insurance policies with respect to certain of our related exposures, certain of these policies are subject to high deductibles; as such, we are, in effect, self-insured for substantially all of our typical claims. Our estimates of liabilities for unpaid claims and associated expenses and the appropriateness of the estimated liability are reviewed and updated quarterly. However, insurance liabilities are difficult to assess and estimate due to the many relevant factors, the effects of which are often unknown, including the severity of an injury, the determination of our liability in proportion to other parties, the number of incidents that have occurred but are not reported, and the effectiveness of our health, safety and quality programs. Our accruals are based on known facts, historical trends (both internal trends and industry averages) and our reasonable estimate of our future expenses. We believe our accruals are adequate. However, our risk management strategies and techniques may not be fully effective in mitigating the risk exposure in all market environments or against all types of risk. If any of the variety of instruments, processes or strategies we use to manage our exposure to various types of risk are not effective, we may incur losses that are not covered by our insurance policies (including potential punitive damages awards) or that exceed our accruals or coverage limits.

Additionally, in recent years, insurance markets have become more expensive and restrictive. Also, our prior casualty loss history might adversely affect our ability to procure insurance within commercially reasonable ranges. As such, we may not be able to maintain commercially reasonable levels of insurance coverage in the future, which could preclude our ability to work on many projects. Our insurance providers are under no commitment to renew our existing insurance policies in the future; therefore, our ability to obtain necessary levels or kinds of insurance coverage are subject to market forces outside our control. If we are unable to obtain necessary levels of insurance, we likely would be unable to compete for or work on most projects.

A material portion of our revenue is recognized using the cost-to-cost method of accounting, which results in recognizing contract revenue and earnings ratably over the contract term in the proportion that our actual costs bear to our estimated contract costs. The earnings or losses recognized on individual contracts are based on estimates of contract revenue, costs and profitability. We review our estimates of contract revenue, costs and profitability on an ongoing basis. Prior to contract completion, we may adjust our estimates on one or more occasions as a result of change orders to the original contract, collection disputes with the customer on amounts invoiced, or claims against the customer for increased costs incurred due to customer-induced delays and other factors. Contract losses are recognized in the fiscal period in which the loss is determined. Contract profit estimates are also adjusted in the fiscal period in which it is determined that an adjustment is required. As a result of the requirements of the cost-to-cost method of accounting, the possibility exists, for example, that we could have estimated and reported a profit on a contract over several periods and later determined, usually near contract completion, that all or a portion of such previously estimated and reported profits were overstated. If this occurs, the full aggregate amount of the overstatement will be reported for the period in which such determination is made, thereby offsetting all or a portion of any profits from other contracts that would be reported in such period, or even resulting in a loss being reported for such period. On a historical basis, in most business units, we believe that we have typically made reasonably reliable estimates of the progress towards completion on our long-term contracts. However, given the uncertainties associated with these types of contracts, it is possible for actual costs to materially and adversely vary from estimates previously made, which may result in reductions or reversals of previously recorded revenue and profits.

We carry a significant amount of goodwill and identifiable intangible assets on our consolidated balance sheets. Goodwill is the excess of purchase price over the estimated fair value of the net assets of acquired businesses. We assess goodwill for impairment each year, and more frequently if circumstances suggest an impairment may have occurred. We may determine in the future that a significant impairment has occurred in the value of our unamortized intangible assets or fixed assets, which could require us to write off a portion of our assets and could adversely affect our financial condition or reported results of operations.

We often warrant the services provided, typically as a function of contract, guaranteeing the work performed against defects in workmanship and the material we supply. If warranty claims occur, we could be required to repair or replace warrantied work in place at our cost. In addition, our customers may elect to repair or replace the warrantied item by using the services of another provider and require us to pay for the cost of the repair or replacement. Costs incurred as a result of warranty claims could adversely affect our financial position, results of operations and cash flows.

The U.S. federal government has in recent years imposed new or increased tariffs or duties on an array of imported materials and goods that are used in connection with our operations. Foreign governments and trading blocs have responded by imposing or increasing tariffs, duties and/or trade restrictions on U.S. goods, and may, from time to time, consider other measures. These trade conflicts and related escalating governmental actions that result in additional tariffs, duties and/or trade restrictions could increase our operating costs, cause disruptions or shortages in our supply chains and/or negatively impact the U.S., regional or local economies in which we operate, and, individually or in the aggregate, materially and adversely affect our business and our consolidated financial statements.

Economic factors, including inflation and fluctuations in interest rates, recession and fears of recession could have a negative impact on our business. If our costs were to become subject to significant inflationary pressures, we may not be able to fully offset such higher costs through price increases. To the extent that Congress is unable to lower United States debt substantially or effectively increase the debt limit, a decrease in federal spending could result, which could negatively impact the ability of government agencies to fund existing or new infrastructure projects. Further, to the extent that Congress invests additional amounts in infrastructure during periods of labor shortages or supply chain disruptions, it may increase our costs or cause us not to find suitable labor, supplies, machinery or raw materials. In addition, all of such actions could have a material adverse effect on the financial markets and economic conditions in the United States and throughout the world, which may limit our ability and the ability of our customers to obtain financing and/or could impair our ability to execute our acquisition strategy. These and related economic factors could have a material adverse effect on our financial position, results of operations, cash flows and liquidity.

The last several years have additional global consequences,been periodically marked by political and economic concerns, including the COVID-19 pandemic, decreased consumer confidence, the effects of international conflicts such as heightened risks of cyberattacks. Our business, financial condition, and results of operations may be materially adversely affected by the negative global and economic impact resulting from the conflict in Ukraine or any other geopolitical tensions.

Borrowings under our Second A&R Wintrust Credit Agreement (as defined below) are at variable rates of interest and expose us to interest rate risk. If interest rates increase, our debt service obligations on the variable rate indebtedness will increase even though any amount borrowed remains the same, and our net income and cash flows, including cash available for servicing our

Our Second A&R Wintrust Credit Agreement and other debt obligations include certain debt covenants, some of which are financial in nature, are further described in “Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations” of this Annual Report on Form 10-K. Our failure to comply with any of these covenants, or to pay principal, interest or other amounts when due thereunder, would constitute an event of default under the applicable agreements. Under certain circumstances, the occurrence of an event of default under one of these agreements (or the acceleration of the maturity of the indebtedness under one of these agreements) may constitute an event of default under one or more of our other debt or surety agreements. Default under our debt agreements could result in, among other things, us no longer being entitled to borrow

under one or more of the agreements, acceleration of the maturity of outstanding indebtedness under the agreements, and/or foreclosure on any collateral securing the obligations under the agreements. If we are unable to service our debt obligations, or if we are unable to comply with our financial or other debt covenants, and our indebtedness would become immediately due and payable, and we could be forced to curtail our operations, reorganize our capital structure (including through bankruptcy proceedings), or liquidate some or all of our assets in a manner that could cause holders of our securities to experience a partial or total loss of their investment.

Our ability to meet all of our existing or potential future debt service obligations (including those under our Second A&R Wintrust Credit Agreement, pursuant to which we may incur significant indebtedness), to refinance our existing or potential future indebtedness, and to fund our operations, working capital, acquisitions, capital expenditures, and other important business uses, depends on our ability to generate sufficient cash flow in the future. Our future cash flow is subject to, among other factors, general economic, industry, financial, competitive, operating, legislative and regulatory conditions, many of which are beyond our control.

We cannot assure that our business will generate sufficient cash flow from operations or that future sources of cash will be available to us on favorable terms, or at all, in amounts sufficient to enable us to meet all of our existing or potential future debt service obligations, or to fund our other important business uses or liquidity needs. Furthermore, if we incur additional indebtedness in connection with future acquisitions or for any other purpose, our existing or potential future debt service obligations could increase significantly and our ability to meet those obligations could depend, in large part, on the returns from such acquisitions or projects, as to which no assurance can be given.

Furthermore, our obligations under the terms of our borrowings could impact us negatively. For example, such obligations could:

We may also refinance all or a portion of our indebtedness at or prior to the scheduled maturity. Our ability to refinance our indebtedness or obtain additional financing will depend on, among other things, (i) our business, financial condition, liquidity, results of operations, and then-current market conditions; and (ii) restrictions in the agreements governing our indebtedness. As a result, we may not be able to refinance any of our indebtedness or obtain additional financing on favorable terms, or at all.

If we do not generate sufficient cash flow from operations and additional borrowings or refinancings are not available to us, we may be unable to meet all of our existing or potential future debt service obligations. As a result, we would be forced to take other actions to meet those obligations, such as raising equity or delaying capital expenditures, any of which could have a

We contribute to approximately 40 multiemployer pension plans in the United States under collective bargaining agreements that generally provide pension benefits to employees covered by these agreements. Approximately 54% of our current employees are members of collective bargaining units. Our contributions to these plans were approximately $11.6 million for the year ended December 31, 2023 and $12.6 million for the year ended December 31, 2022 and $14.3 million for the year ended December 31, 2021.2022. The costs of providing benefits through such plans have increased in recent years. The amount of any increase or decrease in our required contributions to these multiemployer pension plans will depend upon many factors, including the outcome of collective bargaining, actions taken by trustees who manage the plans, government regulations, the actual return on assets held in the plans and the potential payment of a withdrawal liability. Based upon the information available to us from the multiemployer pension plans’ administrators, we believe that some of these multiemployer pension plans are underfunded. The unfunded liabilities of these plans may result in required increased future payments by us and the other participating employers. Underfunded multiemployer pension plans may impose a surcharge requiring additional pension contributions. Our risk of such increased payments may be greater if any of the

participating employers in these underfunded plans withdraws from the plan and is not able to contribute an amount sufficient to fund the unfunded liabilities associated with its participants in the plan.

With limited exception, an employer who is obligated under a collective bargaining agreement to contribute to a multiemployer pension plan is liable, upon termination of such contribution obligation to the plan or withdrawal from a plan, for its proportionate share of the plan’s unfunded vested pension liabilities. In the event that we withdraw from participation in a plan, applicable law could require us to make withdrawal liability contributions to such plan, and we would have to reflect that liability and the related expense in our consolidated financial statements. Our withdrawal liability payable to an individual multiemployer pension plan would depend on the extent of the plan’s funding of vested benefits. While we currently have no intention of withdrawing from a plan, and underfunded plan obligations have not affected our operations in the past, there can be no assurance that we will not be required to make material cash contributions to one or more of these plans in the future. If the multiemployer pension plans in which we participate have significant underfunded liabilities, such underfunding could increase the size of our potential withdrawal liability. No liability for underfunding of multiemployer pension plans was recorded in our consolidated financial statements for the years ended December 31, 20222023 or 2021.2022.

The costs of providing employee healthcare benefits have steadily increased over a number of years due to, among other things, rising healthcare costs and legislative requirements. Because of the complex nature of healthcare laws, as well as periodic healthcare reform legislation adopted by Congress, state legislatures, and municipalities, we cannot predict with certainty the future effect of these laws on our healthcare costs. Continued increases in healthcare costs or additional costs created by future health care reform laws adopted by Congress, state legislatures, or municipalities could adversely affect our results of operations and financial position.

We perform our work under a variety of conditions, including but not limited to, difficult terrain, difficult site conditions, and busy urban centers where delivery of materials and availability of labor may be impacted, clean-room environments where strict procedures must be followed, and sites which contain harsh or hazardous conditions, refineries and other process facilities. Performing work under these conditions can increase the cost of such work or negatively affect efficiency and, therefore, our profitability.

If a pandemic, epidemic, or outbreak of an infectious disease, including the outbreak of any respiratory illness caused by COVID-19, or other public health crisis were to affect our markets or facilities or those of our suppliers, or customers, our business could be adversely affected. Consequences of a pandemic, epidemic or other infectious disease may include disruptions in or restrictions on our ability to travel. If such an infectious disease broke out at one or more of our offices, facilities or work sites, our operations may be adversely and materially affected, our productivity may be affected, our ability to

Greenhouse gas (“GHG”) emissions are driving global climate change that is expected to have various impacts on our operations, ranging from more frequent extreme weather events to extensive governmental policy developments and shifts in our customers’ preferences, which have the potential individually or collectively to significantly disrupt our business as well as negatively affect our suppliers, independent contractors and customers. Experiencing or addressing the various physical, regulatory and adaptation/transition risks from climate change may significantly reduce our revenue and profitability, or cause us to generate losses. For instance, incorporating greater resource efficiency into our solutions, whether to comply with upgraded building codes or recommended practices given a region’s particular exposure to climate conditions, or undertaken to

satisfy demand from increasingly environmentally conscious customers or to meet our own sustainability goals, often raises our costs. In evaluating whether to implement voluntary improvements, we also consider that choosing not to enhance our buildings’ resource efficiency can make them less attractive to municipalities, and increase the vulnerability of customers in our communities to rising energy and water expenses and use restrictions. We weigh the impact of the costs associated with offering more resource-efficient products against our priorities of generating higher returns and delivering solutions that are affordable to our customers. In balancing these objectives, we may determine we need to absorb most or all of the additional operating costs that come with making our solutions more efficient, which may be substantial for us.

Beyond the commercial pressures implicated by climate change concerns, our operations in any of our served markets may face its potential adverse physical effects. While we have safety protocols in place for our construction sites and take steps to safeguard our administrative functions, we can provide no assurance that we or our suppliers or other partners can successfully operate in areas experiencing a significant weather event or natural disaster, and we or they may be more impacted and take longer, and with higher costs, to resume operations in an affected location than other businesses, depending on the nature of the event or other circumstances.

International, federal, state and local authorities and legislative bodies have issued, implemented or proposed regulations, penalties, standards or guidance intended to restrict, moderate or promote activities consistent with resource conservation, GHG emission reduction, environmental protection or other climate-related objectives. Compliance with those directed at or otherwise affecting our business or our suppliers’ (or their suppliers’) operations, products or services, could increase our costs or delay or complicate our solutions, for example, due to a need to reformulate or redesign building materials or components, or source updated or upgraded items or equipment, or specially trained or certified independent contractors, in limited or restricted supply.

Adapting to or transitioning from the use of certain items or methods in construction or other solutions, or adjusting the products we offer to our customers, whether due to climate-related governmental rules or our supply chain, market dynamics or consumer preferences, can negatively affect our costs and profitability, production operations in affected markets and customer satisfaction during the transition period, which could be prolonged.

Climate change is an intrinsically complex global phenomenon with inherent residual risks across its physical, regulatory and adaptation/transition dimensions that cannot be mitigated given their wide-ranging, (sometimes unexpectedly) interdependent and largely unpredictable potential scope, nature, timing or duration. Therefore, we cannot provide any assurance that we have or can successfully prepare for, or are or will be able to reduce or manage, any of them to the extent they may arise. In addition, we may experience substantial negative impacts to our business if an unexpectedly severe weather event or natural disaster damages our operations or those of our suppliers or independent contractors in our primary markets or from the unintended consequences of regulatory changes that directly or indirectly impose substantial restrictions on our activities or adaptation requirements.

Investors have increased their emphasis on the environmental, social and governance ("ESG") practices of companies across all industries, including the environmental impact of operations and human capital management. Certain stockholders use third-party benchmarks or scores to measure a company’s ESG practices and decide whether to invest in its common stock or engage with the company to require changes to its practices. In addition, our customers may evaluate our ESG practices or require that we adopt certain ESG policies as a condition of awarding contracts.

A failure to comply with investor or customer expectations and standards, which are evolving and vary considerably, or the perception that we have not responded appropriately to the growing concern for ESG issues, could result in reputational harm to our business and could have an adverse effect on us.

In addition, organizations that provide ratings information to investors on ESG matters may assign unfavorable ratings to us or our industry, which may lead to negative investor sentiment and the diversion of investment capital to other companies or industries, which could have a negative impact on our stock price and our costs of capital.

Our business may be adversely affected by severe weather in areas where we have significant operations. Repercussions of severe weather conditions may include:

We use sophisticated information technology systems, networks, and infrastructure in conducting some of our day-to-day operations and providing services to certain customers, including technology used for building designs, project modeling and scheduling. Information technology system failures, including suppliers’ or vendors’ system failures, could disrupt our

operations by causing transaction errors, processing inefficiencies, the loss of customers, other business disruptions, or the loss of employee personal information. In addition, these systems, networks, and infrastructure may in the future be vulnerable to deliberate cyber-attacks that interfere with their functionality or the confidentiality of our data or information or our customers’ data or information. Increasingly advanced cyber-attacks against rapidly evolving computer technologies pose a risk to the security of our systems, networks, information and data. In addition, the rapid evolution and increased adoption of artificial intelligence technologies may intensify our cybersecurity risks. Likewise, cyber incidents, including malicious cyber-attacks perpetrated on our employees and cyber incidents caused by third parties surreptitiously accessing our systems by other means, pose aare an on-going risk to the security of the systems, networks, information and data of ours, our customers, subcontractors and suppliers. Despite effortsWhile we have security, internal control and technology measures in place to protect our systems and networks, confidential business information, personal data of ours, our customers, employees, suppliers and subcontractors, our information technology systems and those of our third-party service providers have been and may in the future be subject to system breaches. System breaches can lead to disclosure, modification and destruction of proprietary business data, personally identifiable information, other sensitive information, production downtime or loss of business, and damage to our reputation, competitiveness and operations. In addition, flexible working arrangements at our corporate offices increased as a result of the COVID-19 pandemic, and these arrangements have resulted in a higher extent of remote working. This and other possible changing work practices may adversely impact our ability to maintain the security, proper function and availability of our information technology and systems since remote working by our employees could strain our technology resources and introduce operational risk, including heightened cybersecurity risk. Remote working environments may be less secure and more susceptible to hacking attacks, including phishing and social engineering attempts that have sought, and may seek, to exploit remote working environments. Of special note is our risk when implementing new capabilities. The implementation of new systems and information technology could adversely impact our operations by requiring substantial capital expenditures, diverting management’s attention, or causing delays or difficulties in transitioning to new systems. As we implement new systems, many times both new and old systems run in parallel until all processes have successfully transferred to the new system and thorough testing has been performed. These events could impact our customers, suppliers, subcontractors, employees, our financial reporting and our reputation and lead to financial losses from remediation actions, loss of business or potential liability, or an increase in expense, all of which may have a material adverse effect on our business. Our systems implementations may also not result in productivity improvements at the levels anticipated. In addition, current and future laws and regulations governing data privacy and the unauthorized disclosure of confidential information, including, but not limited to rules implemented by the SEC in 2023, may pose complex compliance challenges and result in additional costs. A failure to comply with such laws and regulations could result in penalties or fines, legal liabilities or reputational harm. The continuing and evolving threat of cyber-attacks has also resulted in increased regulatory focus on risk management and prevention. New cyber-related regulations or other requirements could require significant additional resources and cause us to incur significant costs, which could have an adverse effect on our results of operations and cash flows.

As of December 31, 2022,2023, our business units operate in 2122 states, which exposes us to a variety of state and local laws and regulations, particularly those pertaining to contractor licensing requirements. These laws and regulations govern many aspects of our business, and there are often different standards and requirements in different locations. In addition, our subsidiaries that perform work for federal government entities are subject to additional federal laws and regulatory and contractual requirements. Changes in any of these laws, or any subsidiary’s material failure to comply with them, can adversely impact our operations by, among other things, increasing costs, distracting management’s time and attention from other items, and harming our reputation.

Federal Government Contractors must comply with many regulations and other requirements that relate to the award, administration and performance of government contracts. A violation of these laws and regulations could result in imposition of fines and penalties, the termination of a government contract, or debarment from bidding on government contracts in the future. Further, despite our decentralized nature, a violation at one of our locations could impact the ability of the other locations to bid on and perform government contracts; additionally, because of our decentralized nature, we face risk in maintaining compliance with all local, state and federal government contracting requirements. Prohibition against bidding on future government contracts could have an adverse effect on our financial position, results of operations and cash flows.

The systems we install are subject to various statutes and regulations. There can be no assurance that the regulatory environment in which we operate will not change significantly in the future. Various local, state and federal laws and regulations impose licensing standards on technicians who install and service HVACmechanical systems. And additional laws, regulations and standards apply to contractors who perform work that is being funded by public money, particularly federal public funding. Our failure to comply with these laws and regulations could subject us to substantial fines, the loss of licenses or potential debarment from future publicly funded work. It is impossible to predict the full nature and effect of judicial, legislative or regulatory developments relating to health and safety regulations and environmental protection regulations applicable to our operations.

In certain markets, we rely heavily on our immigrant labor force. We have taken steps that we believe are sufficient and appropriate to ensure compliance with immigration laws. However, we cannot provide assurance that our management has identified, or will identify in the future, all undocumented immigrants who work for us. The failure to identify such illegal immigrants may result in fines or other penalties being imposed upon us, which could have a material adverse effect on our financial position, results of operations and cash flows.

Risks Related to Ownership of Our Common Stock

The market price of our common stock has been volatile and may be volatile in the future, and could be subject to wide fluctuations in price in response to various factors, some of which are beyond our control. These factors include, among other things:

In addition, if the market for stocks in our industry, or the stock market in general, experiences a loss of investor confidence, the trading price of our common stock could decline for reasons unrelated to our business, financial condition or results of operations. If any of the foregoing occurs, it could cause our stock price to fall and may expose us to lawsuits that, even if unsuccessful, could be costly to defend and a distraction to management.

Any transfer or sales of substantial amounts of our common stock in the public market or the perception that such transfer or sales might occur may cause the market price of our common stock to decline. As of March 7, 2023,12, 2024, we had an aggregate of 10,449,68911,131,702 shares of our outstanding common stock, of which 1,351,8031,095,177 shares were held by our current directors and officers. There were no holders of greater than 10% of our common stock as of March 7, 2023.12, 2024. If a substantial number of these shares are sold in the public market, the trading price of our common stock may decline.

In addition, our boardBoard of Directors has the power, without stockholder approval, to set the terms of any series of preferred stock that may be issued, including voting rights, dividend rights, and preferences over our common stock with respect to dividends or in the event of a dissolution, liquidation or winding up and other terms. In the event that we issue preferred stock in the future that has preference over our common stock with respect to payment of dividends or upon our liquidation, dissolution or winding up, or if we issue preferred stock with voting rights that dilute the voting power of our common stock, the rights of the holders of our common stock or the market price of our common stock could be adversely affected.

We are generally not restricted from issuing additional shares of our common stock, up to the 100,000,000 shares of voting common stock authorized by our second amended and restated certificate of incorporation, which could be increased by a vote of the holders of a majority of our shares. In addition, we may issue additional shares of our common stock in the future pursuant to current or future equity compensation plans, upon conversions of preferred stock or debt, upon exercise of warrants or in connection with future acquisitions or financings. If we choose to raise capital by selling shares of our common stock for any reason, the issuance would have a dilutive effect on the holders of our common stock and could have a material negative effect on the market price of our common stock.

The trading market for our common stock could be affected by equity research analysts’ research or reports about us and our business. The price of our stock could decline if one or more securities analysts downgrade our stock or if analysts issue other unfavorable commentary about us or our business. In addition, if any of these analysts ceases coverage of us, we could lose visibility in the market, which in turn could cause our common stock price or trading volume to decline and our common stock to be less liquid.

The payment of cash dividends on our common stock rests within the discretion of our Board of Directors and will depend, among other things, upon our earnings, unencumbered cash, capital requirement and our financial condition, as well as other relevant factors. To date, we have not paid dividends on our common stock nor do we anticipate that we will pay dividends in the foreseeable future. As of December 31, 2022,2023, we do not have any preferred stock outstanding that has any preferential dividends.

The provisions of our Certificate of Incorporation and our bylaws could have the effect of delaying, deferring or discouraging another person from acquiring control of our company. These provisions, which are summarized below, may have the effect of discouraging takeover bids. They are also designed in part to encourage persons seeking to acquire control of us to negotiate first with our Board of Directors. We believe that the benefits of increased protection of our potential ability to negotiate with an unfriendly or unsolicited acquirer outweigh the disadvantages of discouraging a proposal to acquire us because negotiation of these proposals could result in an improvement of their terms.

Our Certificate of Incorporation and our bylaws include a number of provisions that could deter hostile takeovers or delay or prevent changes in control of our company, including the following:

We plan to continue to maintain and strengthen internal controls and procedures to enhance the effectiveness of our disclosure controls and internal controls over financial reporting. Any system of controls, however well designed and operated, is based in

part on certain assumptions and can provide only reasonable, and not absolute, assurances that the objectives of the system are met. Any failure of our disclosure controls and procedures or internal controls over financial reporting could harm our financial condition and results of operations.

A material weakness is a deficiency, or a combination of deficiencies, in internal control over financial reporting such that there is a reasonable possibility that a material misstatement of the annual or interim financial statements will not be prevented or detected on a timely basis. However, if we were unable to maintain effective internal control over financial reporting, or if we identify additional material weaknesses in our internal control over financial reporting, our management would be unable to assert in future reports that our disclosure controls and procedures and our internal control over financial reporting are effective. This could cause investors, counterparties and customers to lose confidence in the accuracy and completeness of our financial statements and reports and have a material adverse effect on our liquidity, access to capital markets and perceptions of our creditworthiness and/or a decline in the market price of our common stock. In addition, we could become subject to investigations by Nasdaq, the SEC or other regulatory authorities, which could require additional financial and management resources. These events could have a material adverse effect on our business, financial condition and results of operations.

We have been and will continue to be named as a defendant in legal proceedings claiming damages in connection with the operation of our business. These actions and proceedings may involve claims for, among other things, compensation for alleged personal injury, workers’ compensation, employment law violations and/or discrimination, breach of contract, or property damage. In addition, we may be subject to lawsuits involving allegations of violations of the Fair Labor Standards Act and state wage and hour laws. We may also face allegations of violations of applicable securities laws, including the possibility of class action lawsuits. Due to the inherent uncertainties of litigation, we cannot accurately predict the ultimate outcome of any such actions or proceedings. We also are, and will likely continue to be from time to time, a plaintiff in legal proceedings against customers, or will pursue claims against our customers prior to litigation in which we seek to recover payment of contractual amounts we are owed, as well as claims for increased costs we incur. When appropriate, we will establish provisions against possible exposures, and adjust these provisions from time to time according to ongoing exposure. If the assumptions and estimates related to these exposures prove to be inadequate or inaccurate, we could experience a reduction in our profitability and liquidity and a weakening of our financial condition. In addition, claims, lawsuits and proceedings may harm our reputation or divert management resources away from operating the business.

Force majeure, or extraordinary events beyond the control of the contracting parties, such as natural and man-made disasters, terrorist actions, and state and federal government shutdowns, could negatively impact us. We attempt to negotiate contract language seeking to mitigate force majeure events in both public and private client contracts. When successful, we remain obligated to perform our services after most extraordinary events subject to relief that may be available pursuant to a force majeure clause. If we are not able to react quickly to force majeure events, our operations may be affected significantly, which may have a negative impact on our financial position, results of operations and cash flows.

Intentional acts of theft, vandalism and destruction could damage or destroy our facilities, as well as the materials and equipment our labor forces are installing, thereby reducing our operational production capacity and requiring us to repair or replace facilities or installed work at substantial cost. Additionally, employees, contractors and the public could suffer substantial physical injury from acts of terrorism for which we could be liable. Governmental authorities may also impose security or other requirements that could make our operations more difficult or costly. The consequences of any such actions could adversely affect our financial position, results of operations and cash flows.

We continue to assess the impact of various U.S. federal or state legislative proposals that could result in a material increase to our U.S. federal or state taxes. We cannot predict whether any specific legislation will be enacted or the terms of any such legislation. However, if such proposals were to be enacted, or if modifications were to be made to certain existing regulations, the consequences could have a material adverse impact on us, including increasing our tax burden, increasing the cost of tax compliance or otherwise adversely affecting our financial position, results of operations and cash flows.

Not applicable.

Information About Our Executive Officers

During the year ended December 31, 2023, 600,000 $15 Exercise Price Sponsor Warrants and its Public606,476 Merger Warrants (as definedwere exercised on a cashless basis by the holders of the warrants, which resulted in the warrants being converted into, and the Company issuing, 167,564 and 274,742 shares of the Company's common stock, respectively. The Company received no proceeds from the cashless exercise of the $15 Exercise Price Sponsor Warrants or the Merger Warrants. The remaining 23,167 unexercised Merger Warrants expired by their terms on July 20, 2023. See Note 8 – Equity in the accompanying notes to the Company’s consolidated financial statements)were quoted on the OTCQB under the symbol “LMBHW.” On July 20, 2021, the Company’s Public Warrants expired by their terms.

Securities Authorized for Issuance under Equity Compensation Plans Information

The information called for by this item is incorporated herein by reference to the material under the caption, “Equity Compensation Plan Information” in the Proxy Statement.

The Company is an integrateda building systems solutionssolution firm whose expertise is in the design, modular prefabrication, installation, managementthat partners with building owners and maintenance of HVAC,facilities managers who have mission critical mechanical (heating, ventilation and air conditioning), electrical, and plumbing and control systems for commercial, institutional and light industrial markets.infrastructure. The Company operates primarilystrives to be an indispensable partner to its customers by providing services that are essential to the operation of their businesses. The Company has more than 1,400 team members in 19 offices across the Northeast, Mid-Atlantic, Southeast and Midwest regions of theeastern United States. In February 2022,The Company’s team members uniquely combine engineering expertise with field installation skills to provide custom solutions that leverage its full life-cycle capabilities, which allows it to address both the Company announcedoperational and capital projects needs of its strategic decision to wind down its

The Company’s core market sectors consist of the following customer base with mission-critical systems:

The Company operates in two segments, (i) GCR, in which the Company generally manages new construction or renovation projects that involve primarily HVAC,mechanical, plumbing, or electrical services awarded to the Company by general contractors or construction managers, and (ii) ODR, in which the Company performs owner direct projects and/or provides maintenance or

service primarily on HVAC,mechanical, plumbing or electrical systems, building controls and specialty contracting projects direct to, or assigned by, building owners or property managers. This work is primarily performed under fixed price, modified fixed price, and time and material contracts over periods of typically less than two years.

Key Components of Consolidated Statements of Operations

The Company generates revenue principally from fixed-price construction contracts to deliver HVAC,mechanical, plumbing, and electrical construction services to its customers. The duration of the Company’s contracts generally ranges from three months to two years. Revenue from fixed price contracts is recognized on the cost-to-cost method, measured by the relationship of total cost incurred to total estimated contract costs. Revenue from time and materials service contracts is recognized as services are performed. The Company believes that its extensive experience in HVAC,mechanical, plumbing, and electrical projects, and its internal cost review procedures during the bidding process, enable it to reasonably estimate costs and mitigate the risk of cost overruns on fixed price contracts.

The Company generally invoices customers on a monthly basis based on a schedule of values that breaks down the contract amount into discrete billing items. Costs and estimated earnings in excess of billings are recorded as a contract asset until billable under the contract terms. Billings in excess of costs and estimated earnings are recorded as a contract liability until the related revenue is recognizable.

Cost of revenue primarily consists of the labor, equipment, material, subcontract and other job costs in connection with fulfilling the terms of ourthe Company’s contracts. Labor costs consist of wages plus taxes, fringe benefits and insurance. Equipment costs consist of the ownership and operating costs of company-owned assets, in addition to outside-rented equipment. If applicable, job costs include estimated contract losses to be incurred in future periods. Due to the varied nature of the Company’sCompany's services, and the risks associated therewith, contract costs as a percentage of contract revenue have historically fluctuated, and it expects this fluctuation is expected to continue in future periods.

Selling, general and administrative (“SG&A”) expenses consist primarily of personnel costs for its administrative, estimating, human resources, safety, information technology, legal, finance and accounting employees and executives. Also included are

The change in fair value of contingent consideration relates to the remeasurement of the contingent consideration arrangementarrangements resulting from each of the Jake Marshall, LLC (“JMLLC”), Coating Solutions, LLC (“CSLLC”) (together with JMLLC, the Jake Marshall Transaction), the ACME Transaction and the Industrial Air Transaction. As a part of the total consideration for the Jake Marshall, Transaction,ACME and Industrial Air transactions, the Company initially recognized $3.1 million, $1.5 million and $3.2 million, respectively, in contingent consideration associated with their respective earnout payments. The carrying values of the Jake Marshall, ACME and IA Earnout Payments (as defined in Note 3 – Acquisitions in the accompanying notes to the Company’s consolidated financial statements). The carrying value of the Earnout Payments isare subject to remeasurement at fair value at each reporting date through the end of the respective earnout periods with any changes in the fair value reported as a separate component of operating income in the condensed consolidated statements of operations. See Note 9 – Fair Value Measurements in the accompanying notes to the Company’s consolidated financial statements for further information.

Amortization expense represents periodic non-cash charges that consist of amortization of various intangible assets primarily including favorable leasehold interests and certain customer relationships in the ODR segment. As a result of the Jake Marshall Transaction, the Company recognized, in the aggregate, an additional $5.7 million of intangible assets associated with customer relationships with third-party customers, the acquired trade name and acquired backlog. TheIn addition, as a result of the ACME Transaction, the Company recognized, in the aggregate, an additional $2.8 million of intangible assets associated with customer relationships with third-party customers and the acquired trade name, inclusive of the impact of certain measurement period adjustments. Lastly, as a result of the Industrial Air Transaction, the Company recognized, in the aggregate, an additional $8.7 million of intangible assets associated with customer relationships with third-party customers, the acquired trade name, trademarks and intellectual property and the acquired backlog. Each of the Jake Marshall-related Marshall, ACME and Industrial Air-related

intangible assets were recorded under the acquisition method of accounting at their estimated fair values at the acquisition date. See Note 3 – Acquisitions in the accompanying notes to the Company’s consolidated financial statements for further discussion of the Company’s acquired intangible assets as a result of the Jake MarshallACME Transaction and the Industrial Air Transaction. In addition, see Note 5 – Goodwill and Intangible Assets for further information on the Company’s intangible assets.

The Company is taxed as a C corporation and its financial results include the effects of federal income taxes, which will be paid at the parent level.

Operating Segments

The Company manages and measures the performance of its business in two operating segments: GCR and ODR. These segments are reflective of how the Company’s Chief Operating Decision Maker (“CODM”) reviews operating results for the

purposes of allocating resources and assessing performance. The Company’s CODM is comprised ofcomprises its President and Chief Executive Officer, Executive Vice President and Chief Financial Officer and Executive Vice President and Chief OperatingFinancial Officer.

As previously discussed, on January 17, 2023, the Company announced its planned transition succession, pursuant to which Charles A. Bacon III stepped down as President and Chief Executive Officer on March 28, 2023, and Michael M. McCann, the Company’s corporate department provides generalformer Executive Vice President and administrative support servicesChief Operating Officer, was appointed President and Chief Executive Officer. Following the transition, the Company revised its segment presentation to align with how Mr. McCann assesses performance and makes resource allocation decisions for its two operating segments. The Company allocates costs between segments, which is based on segment revenue and segment gross profit. SG&A expenses are no longer reported on a segment basis as the Company's current CODM does not review discrete segment financial information for selling, general and administrative and depreciation expense.SG&A in order to assess performance. Interest expense is not allocated to segments because of the corporate management of debt service. See

The following table presents operating results for the years ended December 31, 20222023 and 20212022 in dollars and expressed as a percentage of total revenue (except as indicated below):