The model changed. Did the memo change with it?

A model revision isn't finished when the spreadsheet updates. The committee memo can still describe the old case.

This week, I'd test the handoff with one accepted assumption change and one deliberately stale paragraph.

- Sasha Deneux

Getting property information into an AI assistant keeps getting easier. On October 29, Realmo announced one-click AI analysis from commercial property and listing pages. Its announcement describes passing available listing information to external assistants. That's a vendor announcement about the input handoff, not independent proof of underwriting accuracy or a synchronized investment memo.

The next question is what happens after an analyst changes an assumption.

A narrative can name the correct property, cite the correct source and still describe the wrong case. The rent assumption changed. Insurance changed. Someone accepted a revised expense. The summary was regenerated, but the risk section retained the earlier coverage figure.

I'd judge that workflow by the controlled revision it can explain. Which input changed? Who accepted it? Which outputs depend on it? Can the reviewer recover the preceding version and identify what remains unresolved?

That is a narrower test than asking whether an assistant can write a convincing memo. It is also more useful when the committee needs to challenge a number.

A source link doesn't answer all those questions. Nor does a shared data field. The numerical dependency, the narrative dependency and the review decision each need to survive the change. If the team cannot identify the accepted case, a polished new document only creates another version to inspect.

Use a small synthetic case. Every amount here is an invented teaching input, not client evidence or a financing quote.

Case V1 has annual income before operating expenses of $600,000, other operating expenses of $200,000 and insurance of $40,000. NOI is $360,000. Hold annual debt service at $300,000, giving an illustrative NOI-to-debt-service ratio of 1.20x.

Now introduce an illustrative insurance quote of $55,000. Preserve any historical source record and retain Case V1. Record the proposed annual expense, source reference, effective period, review status and person accepting it. The quotation entering the file is not the same event as the reviewer accepting the assumption.

Once accepted in Case V2, the expense change is $15,000. NOI becomes $345,000 and the ratio becomes 1.15x. Nothing else in this exercise changes. There is no IRR calculation because this small fixture does not provide a complete equity cash-flow series.

Follow the change into four places: the model output, the summary table, the coverage discussion and any approval condition that depends on that coverage. Keep the open diligence list attached. A new accepted insurance assumption doesn't resolve unrelated missing evidence.

Then break the fixture on purpose. Leave “1.20x” in one memo paragraph while the table shows 1.15x.

The review should find that disagreement, identify the preceding case and record the disposition. A second AI pass may flag it, but that flag needs a reference to the accepted inputs and a reviewer. Automatically replacing every instance of 1.20x could also corrupt a paragraph that intentionally describes Case V1.

I'd keep a short impact record: accepted input change, preceding/current case IDs, expected dependent outputs, observed checks, reviewer and unresolved items. Include both arithmetic and wording checks. The test passes when the reviewer can explain the revision, reopen the corrected memo and verify the current-case paragraph against Case V2 while retaining accurate references to Case V1.

For a starting point, the T-12 adjustment register separates historical evidence from underwriting adjustments. It is a reference exercise, not this complete model-to-memo fixture.

We build source-to-model-to-memo workflows around a team's existing documents and review process. Book a demo with a redacted example of an assumption change that was difficult to carry through the memo. The free Underwriting Model Builder supplies instructions and illustrative files that still need analyst reconciliation and formula checks.

Keep the accepted case and the preceding case recoverable. Then test the sentence that should have changed.

Next week: giving an unresolved diligence item a decision owner.

- NextAutomation Team