Due Diligence Checklist · Construction

Due Diligence Checklist for Buying a Construction Company

Before you acquire a contractor in the $1M–$5M range, verify backlog quality, bonding capacity, job cost accuracy, and owner dependency — or risk inheriting problems that erode your return from day one.

Acquiring a lower middle market construction company offers access to a fragmented, relationship-driven industry with strong cash flow potential — but the due diligence process is materially different from buying a software or services business. Revenue is project-based, financials are shaped by percentage-of-completion accounting, and much of the business value may walk out the door if the owner leaves abruptly. This checklist is designed for private equity buyers, strategic acquirers, and individual searchers evaluating specialty or commercial contractors with $1M–$5M in annual revenue. It covers the five most critical areas of inquiry: backlog and WIP quality, licensing and bonding, financial normalization, customer and contract concentration, and labor and subcontractor risk. Work through every item before submitting a final LOI or entering exclusivity.

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Backlog and Work-in-Progress (WIP) Analysis

The backlog is the lifeblood of a construction business. Verify the quality, margin, and contractual status of every open and pending project before assuming revenue continuity.

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Request a formal WIP schedule with contract values, completion percentages, and projected margins for all open projects.

WIP schedules reveal whether recognized revenue matches actual project progress and expose overbilling or underbilling.

Red flag: No formal WIP schedule exists or gross margins in backlog are materially lower than historical averages.

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Review signed contracts for all backlog projects and confirm no owner-dependent termination clauses.

Unsigned or verbal commitments inflate backlog and may not survive ownership transition without client consent.

Red flag: Significant backlog is based on verbal agreements, unsigned bids, or contracts with owner-specific language.

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Analyze gross margin by project type over the past 3 years using job cost reports.

Identifies whether estimating is accurate and which project types are profitable versus margin-dilutive.

Red flag: Gross margins vary widely across similar project types, suggesting poor estimating or undisclosed cost overruns.

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Confirm the percentage of backlog revenue expected to convert within 12 months post-close.

Long-dated or contingent backlog creates revenue risk during the transition period when you are most exposed.

Red flag: More than 40% of backlog is tied to projects with uncertain start dates or regulatory approvals pending.

Licensing, Bonding, and Insurance

Construction businesses operate under strict licensing and bonding requirements that vary by state and trade. Failure to confirm transferability before close can halt operations immediately after acquisition.

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Obtain copies of all state and local contractor licenses and confirm transferability to a new legal entity or owner.

Many licenses are issued to individuals, not entities, and require testing or experience documentation to transfer.

Red flag: Licenses are held personally by the owner with no pathway for transfer or a qualified replacement licensee on staff.

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Review the surety bond history including bonding capacity, current limits, and surety relationship continuity.

Bonding capacity determines which public and commercial projects the business can bid — loss of capacity shrinks the market.

Red flag: Bonding capacity is personally guaranteed by the seller with no evidence the surety will extend credit to a new owner.

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Audit general liability and workers compensation insurance history including loss runs for the past 5 years.

Excessive claims history increases future premiums and signals operational or safety management problems.

Red flag: Loss runs show multiple large claims, experience modification rate above 1.25, or coverage lapses in recent years.

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Confirm all subcontractors carry adequate insurance and are listed as additional insureds on active projects.

Uninsured subcontractors expose the acquired business to liability for injuries and property damage on job sites.

Red flag: Subcontractor certificates of insurance are outdated, missing, or show coverage limits below contract minimums.

Financial Normalization and Job Costing

Construction financials are frequently distorted by percentage-of-completion accounting, owner perks, and informal job costing. Normalizing EBITDA accurately is essential to valuing the business correctly.

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Obtain 3 years of CPA-prepared financial statements and compare revenue recognition to project completion milestones.

Percentage-of-completion accounting can accelerate or defer revenue in ways that misrepresent true annual performance.

Red flag: Revenue recognition policies are inconsistent across years or financial statements are compiled without CPA involvement.

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Identify and quantify all owner add-backs including personal vehicle, travel, salary above market, and family payroll.

Overstated expenses reduce reported profit; removing them accurately is required to calculate true EBITDA.

Red flag: Owner claims add-backs exceeding 15–20% of revenue without documentation or third-party substantiation.

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Review job cost reports at the project level and reconcile to the general ledger for the past 3 years.

Job-level cost reports reveal whether overhead is allocated correctly and whether margins are as reported.

Red flag: Job cost reports are incomplete, missing for major projects, or cannot be reconciled to financial statements.

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Assess working capital requirements including receivables aging, retainage balances, and billing cycle patterns.

Construction businesses are capital-intensive; understanding cash conversion cycles prevents post-close liquidity surprises.

Red flag: Receivables over 90 days exceed 20% of total AR or retainage balances are held on completed projects without resolution.

Customer and Contract Concentration

Project-based revenue creates natural concentration risk. Evaluate whether key clients will remain post-close and whether any single relationship poses an outsized threat to revenue continuity.

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Calculate revenue concentration for the top 5 clients as a percentage of total revenue for each of the past 3 years.

Concentration above 25–30% in a single client creates catastrophic revenue risk if that relationship does not transfer.

Red flag: One client represents more than 30% of revenue and has no written contract or personal relationship with the owner only.

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Review all master service agreements, GC relationships, and preferred vendor arrangements for change-of-control provisions.

Change-of-control clauses can void contracts or require client consent before a new owner can perform work.

Red flag: Key MSAs or GC relationships include automatic termination rights triggered by ownership transfer.

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Interview or survey 3–5 key clients to assess relationship transferability and satisfaction with the business.

Confirms whether loyalty is tied to the owner personally or to the brand, team, and quality of work delivered.

Red flag: Multiple clients indicate they work with the business exclusively because of the current owner's personal involvement.

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Assess the pipeline of new project opportunities and evaluate how leads are generated and by whom.

An owner-driven sales process with no documented pipeline creates a cliff in new revenue post-transition.

Red flag: All estimating, bidding, and business development activity is performed solely by the owner with no team involvement.

Labor, Subcontractors, and Contingent Liabilities

Field labor reliability, subcontractor relationships, and unresolved project disputes are among the most underestimated risks in construction acquisitions. Investigate thoroughly before close.

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Review all open and closed project disputes, mechanic's liens, warranty claims, and pending or threatened litigation.

Construction disputes often surface months or years after project completion and can result in significant cash obligations.

Red flag: Active liens, unresolved warranty claims, or litigation that has not been disclosed in the seller's representations.

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Assess key foreman and project manager retention risk and review any existing employment agreements or non-competes.

Loss of experienced field leadership post-close can stall project execution and damage client relationships immediately.

Red flag: No employment agreements exist and top foremen or PMs have expressed interest in leaving or starting competing firms.

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Confirm whether work is performed by employees or subcontractors and review any union or prevailing wage obligations.

Misclassified workers or undisclosed prevailing wage requirements create significant legal and financial exposure post-close.

Red flag: Subcontractors are consistently used for core trade work with no written agreements and potential misclassification risk.

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Evaluate key subcontractor relationships for exclusivity, pricing history, and availability in current labor market conditions.

Preferred subcontractor access is a competitive advantage — losing it post-close affects bid competitiveness and margin.

Red flag: No written subcontractor agreements exist and key subs have informal, owner-only relationships with no loyalty to the business.

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Deal-Killer Red Flags for Construction

  • The owner is the sole estimator, primary client contact, and field supervisor with no qualified replacement on staff.
  • Bonding capacity is personally underwritten by the seller and the surety declines to extend credit to the incoming buyer.
  • One client accounts for more than 35% of revenue and has no written contract in place with the business entity.
  • Job cost reports cannot be reconciled to financial statements, indicating informal or unreliable accounting practices.
  • Active mechanic's liens, unresolved warranty claims, or undisclosed litigation exist on closed or in-progress projects.

Frequently Asked Questions

What is the most important financial document to request when buying a construction company?

The WIP (work-in-progress) schedule is the single most important document. It shows the status, margin, and billing position of every open project and is the foundation for understanding true backlog value. Pair it with 3 years of job cost reports reconciled to financial statements to assess estimating accuracy and historical margin performance.

How do I evaluate whether a construction company's backlog will survive ownership transition?

Review every open contract for change-of-control clauses, client consent requirements, and owner-specific language. Then assess whether the relationships driving that backlog are tied to the brand and team or exclusively to the seller. Interviewing 3–5 key clients during diligence — with seller consent — is one of the most reliable ways to gauge transferability before you close.

What bonding and licensing issues should I watch for when acquiring a specialty contractor?

Confirm that all state and local licenses are held by the entity or a transferable qualifier — not solely by the owner as an individual. For bonding, verify the surety will extend credit to a new owner at equivalent capacity, since personal financial guarantees from the seller often do not transfer. Losing bonding capacity post-close can immediately eliminate eligibility for public and commercial work.

How should I structure a construction company acquisition to protect against contingent liabilities from past projects?

Use an asset purchase structure rather than a stock purchase to limit assumption of pre-close liabilities. Include a holdback escrow of 5–10% of the purchase price held for 12–24 months to cover warranty claims, liens, or disputes that surface post-close. Require comprehensive seller representations and warranties covering all known disputes, claims, and open project obligations, and consider representations and warranties insurance for additional protection.

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