Commercial Property Due Diligence Checklist: What Brokers and Buyers Need Before Closing
Commercial property due diligence is the structured investigation between purchase agreement and closing. It covers physical condition, financial verification, legal review, and environmental assessment. This checklist organizes what every buyer and broker should request, inspect, and confirm before commercial real estate closes in Washington State.
The four pillars of commercial due diligence
Commercial due diligence has four working categories. A complete due diligence file covers all four. The most expensive surprises after closing typically come from the category the buyer or broker spent the least time on.
- Physical condition — what is actually there and what shape it's in
- Financial — does the property perform the way the seller represents
- Legal & title — clean ownership, leases, zoning, and permits
- Environmental & market — site contamination history and submarket conditions
Pillar 1: Physical condition checklist
Physical due diligence is where unexpected six-figure capital needs surface. The standard scope:
☐ Property Condition Assessment (PCA)
A full commercial inspection by a CCPIA-certified commercial property inspector. Documents the condition of the roof, envelope, structure, electrical, plumbing, HVAC, life-safety systems, interior conditions, and accessible site features. Produces a written report with photographs, findings, and recommendations. Property-specific "cost to cure" projections available as an additional service. Typical timeline: 1-2 weeks from order to delivered report.
☐ Phase I Environmental Site Assessment (ESA)
Required by nearly all commercial lenders. Reviews historical records, regulatory database searches, and a site visit to identify "Recognized Environmental Conditions" (RECs). If any are found, a Phase II investigation may follow. Performed by an environmental professional, not the inspector. Typical timeline: 2-3 weeks.
☐ Roof age and condition documentation
Roof replacement is one of the largest single capital expenditures in commercial real estate. Confirm: roof age, warranty status, last replacement or recoat date, prior leak history, current condition, and remaining service life estimate. The PCA will document this — verify the seller's warranty paperwork independently.
☐ Mechanical equipment age and service records
RTU age, boiler/chiller age, water heater age, elevator service records (if applicable), and life-safety equipment inspection records. Equipment within five years of typical end-of-life should be priced into the buyer's capital plan.
☐ Accessibility review
Parking, path-of-travel, primary entry, restrooms, and accessible features. The PCA documents observable accessibility considerations; a separate accessibility/ADA compliance survey by a certified accessibility specialist may be warranted on properties with high public traffic or known accessibility complaints.
☐ Sewer scope (recommended on older properties)
Properties built before 1985 often have aging cast iron drain stacks, clay laterals, or root-intruded sewer lines. A sewer scope by camera identifies blockages, breaks, and replacement-grade conditions before they become tenant complaints.
Pillar 2: Financial verification checklist
The seller's pro forma rarely matches the actual operating reality of the property. Verify each line independently.
- ☐ Rent roll — current tenants, lease start/end dates, rent escalations, options, security deposits
- ☐ Tenant lease copies — full executed leases for every tenant, including amendments and side letters
- ☐ Three years of operating statements — verify against tax returns and bank deposits
- ☐ Three years of property tax records — including any pending appeals or special assessments
- ☐ Three years of utility bills — water, electric, gas, garbage; identify any anomalies
- ☐ Service contracts — HVAC maintenance, landscaping, janitorial, security, elevator service
- ☐ Capital expenditure history — every major repair or replacement in the past five years
- ☐ Tenant correspondence and complaints — patterns of complaints often predict near-term capital needs
- ☐ Estoppel certificates — signed confirmation from each tenant that the lease terms are as represented
- ☐ Insurance loss runs — five-year claim history; predicts future insurability and premium
Pillar 3: Legal and title checklist
- ☐ Preliminary title report — review for liens, encumbrances, easements, and exceptions
- ☐ ALTA/NSPS land title survey — required by most commercial lenders; confirms boundaries, easements, encroachments
- ☐ Zoning verification letter — confirm current use is conforming and any planned use is permitted
- ☐ Certificate of Occupancy — current and applicable to the existing use
- ☐ Permit history — confirm all improvements were permitted; unpermitted work is a buyer liability
- ☐ Building department records — open code violations, complaints, or pending enforcement actions
- ☐ Fire marshal records — sprinkler system inspections, fire alarm test records, occupancy classifications
- ☐ Pending litigation — any active or threatened litigation involving the property or seller
- ☐ HOA or association documents — if applicable, including assessments and pending special projects
Pillar 4: Environmental and market checklist
- ☐ Phase I ESA — covered above under physical, but functions as the legal basis for "innocent landowner" protection under CERCLA
- ☐ Phase II ESA (if Phase I identifies RECs) — soil and groundwater sampling
- ☐ Asbestos and lead paint surveys — for buildings constructed before 1980
- ☐ Mold and indoor air quality assessment — for buildings with prior water intrusion history
- ☐ Submarket comparables — recent sales of similar properties; broker can supply
- ☐ Submarket lease comparables — confirm in-place rents are at, above, or below market
- ☐ Demographic and traffic data — for retail and hospitality properties especially
- ☐ Local economic development pipeline — pending developments that could affect value
Recommended due diligence timeline
For a typical 45-day due diligence period, the working timeline below leaves enough buffer for re-inspection or follow-up if findings warrant it.
| Days from PSA | Action |
|---|---|
| Day 1-3 | Send seller document request; order title; engage inspector and environmental consultant |
| Day 4-10 | Receive seller documents; begin financial review; schedule property inspection |
| Day 10-20 | Property Condition Assessment performed; Phase I ESA performed; survey ordered |
| Day 20-30 | PCA report received; Phase I report received; financial reconciliation; tenant estoppels returned |
| Day 30-40 | Negotiate retrade or seller credits if findings warrant; finalize lender package; complete legal review |
| Day 40-45 | Final walkthrough; remove contingencies or terminate; prepare for closing |
Common due diligence mistakes that cost buyers money
Treating the inspection as a formality
The Property Condition Assessment is the most underused negotiation tool in commercial real estate. Buyers who walk into the inspection assuming they will buy regardless leave money on the table. A well-documented capital needs finding is a basis for retrade — but only if the buyer is willing to use it.
Accepting the seller's pro forma without verification
Sellers prepare pro formas to support the asking price. Verify every line against tax returns, bank deposits, and utility bills. If a number can't be verified, treat it as suspect.
Skipping tenant estoppels
A signed estoppel certificate from each tenant confirms the lease is as represented and there are no unwritten agreements. Buyers who skip this step occasionally discover side letters, rent abatements, or improvement promises after closing.
Underestimating roof and HVAC capital needs
Roof and HVAC are the two most expensive system replacements in commercial real estate. A roof at end-of-life can be a $150,000 to $400,000+ surprise. HVAC equipment fleet replacement on a multi-tenant building can exceed $250,000. Both should be specifically priced into the buyer's underwriting if the inspection identifies remaining service life under five years.
When to engage the inspector — early or late in due diligence?
Engage the commercial property inspector in the first three days of the due diligence period. Two reasons:
- Scheduling. Quality commercial inspectors are typically booked one to three weeks out. Waiting until day 15 of a 45-day due diligence period creates schedule pressure.
- Findings drive other workstreams. The inspector may identify issues that warrant additional specialist engagement — a structural engineer, an environmental consultant, an HVAC contractor for a load assessment. Time to engage those specialists has to fit inside the due diligence window.
Order your Property Condition Assessment
Optimized CPI delivers CCPIA-standard commercial property condition assessments across Western Washington. Bryan typically returns a written quote within one business day of the request.
Request a Quote →Frequently asked questions about commercial due diligence
How long is a typical commercial due diligence period?
Commercial due diligence periods typically run 30 to 60 days for most transactions in Washington State. Larger or more complex deals may negotiate 90 days or more. Smaller cash transactions occasionally close in 21 days. The period is negotiated as part of the purchase agreement.
What is a Property Condition Assessment (PCA)?
A Property Condition Assessment is the standard term for a commercial property inspection performed for due diligence purposes. It documents the condition of the building's physical systems and produces a written report with findings and recommendations. Property-specific "cost to cure" projections are available as an additional service.
What documents should a buyer request from the seller?
A standard seller document request includes: rent roll and tenant lease copies, three years of operating statements, three years of utility bills, property tax records, capital expenditure history, tenant correspondence, copies of service contracts, prior inspection reports, accessibility documentation, and copies of permits and certificates of occupancy.
Can a commercial inspection be a basis for renegotiating price?
Yes. Inspection findings are a common basis for retrade negotiation. If the inspection identifies deferred maintenance or capital needs that materially exceed the buyer's underwriting, the buyer can request a price reduction, seller credit, completion of repairs prior to closing, or use the findings to terminate within the due diligence period.