What Is Source-Backed CRE Underwriting? A Workflow Where Every Number Has Receipts

The hardest part of CRE underwriting is getting to an answer the team can trust. A fast memo is useful, but investment work still has to survive source checks, assumption review, model edits, lender questions, and the next person opening the file two weeks later.

The questions a workflow has to answer

A serious underwriting workflow should answer simple questions without making the team hunt through folders and chat threads. Where did this number come from? Which assumption changed? What still needs review? Can the work get back into Excel? Can another person understand the logic without starting from scratch?

• What source supports this rent, expense, lease, or market assumption?
• Which values are extracted facts and which values are analyst assumptions?
• What changed between draft, review, and final output?
• Which parts of the work can move into Excel, IC, lender, or broker-facing materials?

The source layer is broader than one document

For multifamily and self-storage teams, the source layer usually includes OMs, rent rolls, T-12s, leases, spreadsheets, broker notes, market context, and internal comp history. For brokers and lenders, the same source discipline supports BOVs, pitch materials, credit memos, DSCR, debt yield, covenant sensitivity, and the evidence trail behind the conclusion.

Facts and assumptions should not look the same

Source-backed underwriting means facts stay attached to evidence. Assumptions are not treated like facts. They can be drafted, edited, approved, rejected, or left open for review. That distinction matters because a rent roll field, a T-12 adjustment, an exit-cap assumption, and a lender term should not carry the same confidence just because they appear in the same output.

Market context should stay attached to the model

Approved market data makes the workflow more useful when it is tied to the model instead of floating in another tab. Rent comps, sales comps, cap-rate ranges, occupancy and supply context, debt terms, public records, and chart-of-account benchmarks can all support better assumptions when the source, freshness, and confidence are visible.

The compounding advantage is reusable firm intelligence

This is also where reusable firm intelligence becomes an underwriting advantage. Deal facts, sources, assumptions, comps, market-source context, prior decisions, and reusable knowledge can compound across the workflow. Deal workspaces are where a team applies that intelligence to a specific deal, market, BOV, IC package, lender review, or analysis task.

Cactus is focused on making the work behind CRE judgment faster, more reviewable, and easier to reuse. The goal is not to replace judgment or hide the model. The goal is to keep documents, assumptions, review, audit history, Excel-ready outputs, presentation materials, and reusable firm intelligence connected long enough for the work to be trusted.