How to create a claims and defenses evidence matrix for Commercial Lease Disputes

Create a commercial lease claims and defenses evidence matrix by breaking each pleaded or proposed theory into propositions requiring proof, then connecting each proposition to the operative lease language, governing authority, favorable and adverse evidence, witnesses, and unresolved gaps. Keep liability, entitlement to remedies, and damages calculations separate. The resulting deliverable should show what the record supports, what remains disputed, and which targeted evidence task could change counsel’s assessment—not merely catalogue documents or repeat the pleadings.

When to use this workflow

Use this workflow when landlord or tenant counsel must assess a rent demand, disputed operating-expense reconciliation, repair-related defense, default notice, or termination position against an incomplete record. It is particularly useful after initial collection or a substantial production, when scattered documents must become testable propositions.

The scope is evidence analysis, not a complete discovery or trial plan. Establish the forum, governing substantive law, operative pleadings, and requested relief first. The federal procedural and evidence rules cited below apply within their respective federal scope; state courts and arbitration require separate checks. They do not supply substantive commercial-lease law. Federal Rules of Civil Procedure, Rule 1; Federal Rules of Evidence, Rule 1101. (uscourts.gov)

Treat the steps below as workflow recommendations. Determine contractual rights from the actual language, applicable law, and facts rather than assuming that a repair complaint excuses payment or a notice defect defeats every remedy.

What you need

Gather the executed lease, incorporated exhibits, amendments, assignments, guaranties, estoppels, and side letters. Identify missing signatures or schedules before treating a document as operative.

Collect default notices and delivery records, maintenance tickets, inspection photographs, correspondence, property-manager exports, rent ledgers, invoices, and bank records. Include unfavorable documents. Obtain the pleadings and a counsel-verified authority list identifying the propositions each theory requires.

Create stable document IDs and identify relevant landlord, tenant, manager, broker, and accountant custodians. Preserve native accounting files, attachments, metadata, and collection provenance. Record whether witnesses personally handled events or learned about them later. Prioritize departing personnel and expiring portal access.

Use the template

Use the Commercial Lease Disputes — Claims and defenses matrix below. Copy this table into your working document or spreadsheet, adding one row per distinct proposition.

Give each row a stable identifier: L-01 for liability, F-01 for a defense, R-01 for remedy entitlement, or D-01 for damages. Identify whose proposition the row tests; “supporting” means supporting that proposition, not necessarily helping your client. Record the burden only after legal verification.

The clause/authority field should identify the operative provision and the authority supporting the legal test. A lease citation does not establish every element of a claim or defense.

Use document IDs with section, page, Bates, transaction, or spreadsheet-cell references. “Ledger supports rent” is insufficient; “ACCT-04, March tab, cells F18:F24” is traceable. Identify the witness or record source needed to explain the evidence. Distinguish supported, disputed, missing, and legal question open rather than assigning unexplained confidence scores.

Step by step

1. Define the theories and separate the proof questions

Start with the pleadings, demand, and client objectives. For each claim or defense, list the propositions counsel must establish under the selected law. Mark proposed theories separately from pleaded ones. Research notice, waiver, mitigation, and remedies independently rather than assuming uniform commercial-lease rules.

Separate a claimed payment failure from termination entitlement and the amount recoverable. A document may matter to all three but answer different questions. Record each proposition, its verified burden, and authority with a pinpoint. If the legal test remains unresolved, assign research rather than inventing an element. Distinguish a denial that a charge was contractually owed from an affirmative defense; leave classification open until verified.

2. Map each proposition to the operative lease obligation

Identify the relevant clause version, responsible party, trigger, performance standard, exceptions, notice mechanism, cure language, and asserted remedy. Check amendments affecting commencement, rentable area, repair allocation, payment application, or notice addresses.

Accounting provisions deserve separate treatment. The SEC-filed DexCom office lease illustrates estimated charges and annual reconciliation; section 3.2(b) conditions audit rights on specified payment and confidentiality requirements. This is contractual wording, not a rule for other leases or evidence of market practice. Exhibit 10.20, section 3.2. (sec.gov)

Record the actual clause citation and unresolved version conflicts. Keep contractual audit conditions distinct from litigation discovery questions.

3. Attach supporting and adverse evidence to each row

Read the source, not merely its filename or review summary. Attach the strongest supporting and contrary evidence with pinpoints. Distinguish contemporaneous records, later recollection, and counsel inference.

For notice disputes, separate preparation, dispatch, delivery, receipt, and cure attempts. Test each event against the lease’s specified mechanism rather than treating an email attachment as proof of compliant delivery. For repairs, distinguish the reported condition from responsibility, access, response, and alleged business impact.

Record contradictions directly in the adverse-proof field. If an attachment is missing or a photograph lacks an established date, mark the limitation. Enter “not located in reviewed materials,” not “does not exist,” unless the record supports that stronger statement.

4. Test witnesses, provenance, and evidentiary foundations

Identify who can explain each important item, their role and employment dates, and their knowledge basis. A manager may understand a ledger export without having witnessed the original payment allocation.

In applicable federal proceedings, Rule 901(a) requires sufficient evidence that an item is what its proponent claims. Rule 803(6) separately addresses qualifying regularly conducted activity records. Authentication alone does not resolve hearsay or other objections. Federal Rules of Evidence, Rules 901 and 803(6). (uscourts.gov)

Record foundation tasks, such as identifying an export custodian or obtaining the complete email chain. Maintain a restricted analytical version and separately review any version intended for disclosure. Do not assume that labeling the matrix privileged establishes protection; assess the applicable protection before circulation.

5. Reconcile monetary propositions without hiding assumptions

Reconstruct rent and operating-expense charges by period and category. Test commencement dates, escalations, abatements, allocation percentages, exclusions, caps, gross-ups, credits, deposits, interest, and payment applications against the operative documents. Link each monetary row to cells in a separate calculation workpaper.

Show competing treatments explicitly. Do not silently net disputed credits or treat an asserted business loss as an established rent offset. Record the legal question separately from the arithmetic and distinguish unpaid principal from interest or other claimed remedies.

A working spreadsheet is not automatically admissible. Federal Evidence Rule 1006 addresses evidentiary summaries of voluminous admissible materials and reasonable access to underlying originals or duplicates. Rule 1006. (uscourts.gov) Record calculation sources, assumptions, and missing invoice-level support.

6. Convert gaps into targeted evidence tasks

Ask what additional evidence could materially change each row. Replace “obtain more documents” with a defined custodian, date range, record type, and proposition.

For federal district-court discovery, Rule 26(b)(1) limits discovery to nonprivileged matters relevant to claims or defenses and proportional to the case; discoverability does not require admissibility. Federal Rules of Civil Procedure, Rule 26. (uscourts.gov) Use the matrix to explain why a focused request matters.

Where organizational knowledge is needed, consider a Rule 30(b)(6) topic. The rule requires reasonably particular topics, good-faith conferral, and testimony concerning information known or reasonably available to the organization. Rule 30(b)(6). (uscourts.gov) Record the task, owner, and source; verify procedural requirements separately.

7. Review the assessment against the complete record

Have a second reviewer test decisive rows against cited documents and contrary explanations. Ask whether each proposition is supported, merely plausible, or dependent on a legal ruling. Resolve duplicates and inconsistent descriptions of the same event.

Record the assessment and decision it informs: further collection, a focused interview, calculation revision, or remedy research. Prioritize gaps by their potential to change that decision. Assign every material unresolved issue. When evidence changes the assessment, update affected rows and retain a dated explanation of the change.

Worked example

Fictional scenario: Alder Quay Properties leases office space to Meridian Instrument Labs. Counsel represents the landlord. A reconciliation demands $72,000 in additional operating expenses, including a $30,000 roof charge. The landlord also asserts termination rights after notice. The tenant disputes the roof charge and says a $20,000 transfer was not credited.

The fictional lease requires notice by a specified delivery method to an address changed by amendment. It excludes roof-replacement capital costs but permits ordinary roof-maintenance costs. Counsel has the lease, amendment, reconciliation, dispatch email, bank confirmation, and partial invoices. The actual work scope, transfer allocation, delivery, and governing legal tests remain unresolved. All parties, documents, amounts, and clauses below are fictional.

The matrix changes the next decision. Counsel should not treat $72,000 as established unpaid principal until tracing the transfer. The invoice description supports investigating the exclusion, but the inconsistent categorization and incomplete scope prevent a final adjustment. Even if both tenant positions succeed factually, counsel should not simply subtract $50,000 without checking overlap and allocation. The notice discrepancy calls for delivery evidence and legal analysis, not an automatic conclusion about termination.

Common mistakes

• One row for the entire breach claim. Split payment, notice, remedy entitlement, and amount into independently testable propositions.
• Using the latest lease PDF without checking amendments. Trace each obligation to its operative version and identify missing incorporated documents.
• Treating repair complaints as an established rent defense. Separate condition, responsibility, evidence, and the legal connection to payment.
• Calling the ledger the damages analysis. Reconcile bank records, invoices, credits, and lease mechanics; preserve alternative calculations.
• Omitting adverse evidence. Place it beside supporting proof and identify what could resolve the contradiction.

Final quality check

• Every material proposition has a stable row and a verified legal basis or assigned research question.
• Clause citations reflect amendments and incorporated documents.
• Supporting and adverse sources have verified IDs and pinpoints.
• Notice events distinguish dispatch, delivery, receipt, and cure activity.
• Monetary rows link to reproducible calculations and explicit assumptions.
• Witness knowledge and foundation gaps are identified without assumed testimony.
• Every material open issue is resolved or assigned; circulation versions receive privilege and confidentiality review.

Complete the workflow with DecoverAI

DecoverAI is the Legal Intelligence Platform for litigation and transactions. Document review, evidence analysis, privilege and confidentiality analysis, and chronology capabilities can support review of lease performance and notice events. Tabular review supports work across multiple documents; the matrix remains counsel’s work product. Use the resulting analysis to inform deposition preparation, retaining legal and evidentiary judgment. To discuss this workflow, book a demo.

Frequently asked questions

Should the matrix include defenses that are not pleaded?

Yes, if clearly marked as proposed and subject to legal and procedural review. Separate evidence supporting a possible defense from conclusions about its availability or procedural status. Do not imply that adding a row amends the pleadings.

How should conflicting rent calculations appear?

Use separate damages rows or linked scenarios. Identify differing assumptions, clause support, and evidence needed to choose between them. Do not average competing positions or conceal disputed credits. Keep arithmetic differences separate from unresolved legal entitlement.

Is the matrix itself a trial exhibit?

Maintain it as an internal analytical document unless counsel decides otherwise. Before external use, review protection, confidentiality, foundation, and admissibility. A matrix containing legal impressions and unresolved assertions is not automatically an admissible summary; Rule 1006 requires separate analysis.

What if a critical notice or invoice cannot be found?

Mark the proof missing, identify likely custodians and alternative sources, and assign focused collection. Explain which conclusion depends on it. Do not replace absent evidence with an unsupported reconstruction or describe an unsuccessful search as proof that no document existed.

Sources

• Federal Rules of Civil Procedure: Rules 1, 26(b)(1), and 30(b)(6).
• Federal Rules of Evidence: Rules 803(6), 901, 1006, and 1101.
• SEC-filed DexCom office lease, Exhibit 10.20: section 3.2, contractual wording example only.

Scope: US workflow guide using the October 13, 2026 research cutoff, not advice for a particular dispute.

This guide is general information about legal workflows, not legal advice for any matter. It was drafted and reviewed with AI assistance. The worked example is fictional. Contract rights and procedure depend on the governing law, the actual wording, and the facts, so check the cited sources and the rules that apply in your jurisdiction before relying on it.