Commercial Real Estate Risk Flags: The 8 Underwriting Killers

Tenant and Lease Risk Flags

The first three killers all live on the rent roll. Tenant concentration is flag one: a single tenant generating more than 25% of revenue on a single-tenant or small-multi-tenant deal turns the property into an operating-business credit. Lenders price for that, with rate premiums of 50–150bps and lower leverage. On true single-tenant net leases (the lease is the asset), lenders underwrite the tenant's credit, not the property — and a non-investment-grade tenant materially limits financing options.

Flag two is lease-rollover concentration. If 35%+ of revenue rolls in the next 24 months on a single-tenant or anchor-tenant deal, the property is mid-cycle in its lease. Lenders apply renewal-probability haircuts and reserve for downtime. Flag three is below-market rent gaps that require capex to close. A property where in-place rents are 25% under market because units need $30K each in unit upgrades has $30K-per-unit of latent capital obligation that doesn't appear on the P&L.

Property Condition and Environmental Flags

Flag four is deferred maintenance. The Property Condition Report (PCR) flags every system needing replacement within five years, and lenders reserve for each at projected replacement cost ÷ remaining useful life. A 10-year-old roof flagged for replacement adds $5K–$30K per year to expenses depending on building size. A failing HVAC system on a small-multi-tenant property can add $10K+ annually. Stack three or four of these and the deal's NOI moves materially.

Flag five is non-conforming use. Properties that depend on a special-use permit or grandfathered zoning are vulnerable to zoning changes, permit-renewal failures, and any operations gap that breaks the grandfathering. Lenders demand a current zoning letter on any property with a non-conforming designation.

Flag six is Phase I environmental findings — even Recognized Environmental Conditions (RECs) without confirmed contamination can stop SBA financing cold and slow conventional financing by 60+ days. Real environmental contamination usually requires Phase II testing and a No Further Action letter from the state, both of which add cost and time and can de-rail a deal entirely.

Insurance and Capital-Stack Flags

Flag seven is flood zone designation. Properties in FEMA Special Flood Hazard Areas require lender-mandated flood insurance, which on commercial properties can run 2–10x what residential flood insurance costs — sometimes $40K+ per year on a single building. The deal still closes, but underwritten NOI takes the hit and DSCR moves accordingly. Properties with mapped flood-zone changes pending (post-Katrina, post-Harvey, post-Helene reform) carry forward risk that prudent lenders are now beginning to price.

Flag eight is seller-financing structure. On SBA deals especially, seller notes have to follow specific standby rules: 24-month full standby for full-credit toward equity, partial standby for partial credit, and any seller-note structure that doesn't comply with SBA SOP 50 10 6 will get re-trades or denials at credit committee. Conventional and agency lenders are more flexible but still require the seller note to be subordinated and current-pay or fully-deferred — never something in between.

How to Screen All Eight in 30 Minutes

Each of the eight flags is detectable in under 30 minutes if you know to look. Half are visible in the OM: tenant concentration shows up in the rent roll, lease rollover shows up in the rent roll, below-market rent gaps show up in the rent comp data, and seller-financing structure shows up in the LOI itself. The other half need quick records pulls.

County GIS for flood zones takes 60 seconds. Permit office calls for non-conforming use take 5 minutes. PCR review against industry benchmarks takes 10 minutes if you have a benchmark. Phase I review for any RECs takes another 10 minutes. The process scales — most experienced operators have a 30-minute pre-LOI screen they run before they sign anything.

For buyers without that workflow, the fastest path is automation: a pre-LOI report that screens all eight flags in parallel and surfaces any blocker before earnest money. Done well, it shifts the conversation from "is this a good deal" to "what do I need to verify in DD" — which is the conversation that actually closes deals.