Evaluating SFR Replacement Properties Inside the 45-Day Window

The 45-day identification window is the tightest constraint in a 1031 exchange, and it lands right when you have the least time to spare: you’re mid-sale, coordinating with a qualified intermediary, and now expected to underwrite three to ten candidate properties well enough to defend the decision later.

Most investors default to a spreadsheet. It works, until you’re re-entering the same fields from a fourth offering memo at 11pm and the cap rate math stops matching what the broker told you on the phone.

What actually needs to happen in 45 days

Three things, realistically:

Get consistent financials for every candidate property. Purchase price, rent, expenses, cap rate, and cash-on-cash return, extracted the same way every time so properties are actually comparable.
Apply one standard, regardless of who’s selling. A broker’s pro forma and a seller’s offering memo are both optimistic by default. You need a fixed set of rules, applied the same way to every property, or you’re not really comparing anything.
Look past year one. A property that pencils today on a seller’s numbers can still be a poor hold if local rent growth, vacancy, or expense assumptions don’t support it over a multi-year hold.

Where this breaks down with spreadsheets

Spreadsheets don’t fail because the math is wrong, they fail because there’s no fixed framework behind them. Every property gets a slightly different set of assumptions depending on who built the sheet and when, which means the eventual decision is defensible only in the sense that “it seemed reasonable at the time.”

That’s the gap Portfolio Builder is built to close: consistent extraction from offering memos, a fixed five-filter scoring engine (the Fiduciary Filter), and 30-year projections that use per-market assumptions rather than whatever the offering memo assumes. The output is a verdict, INVEST, CAUTION, or REJECT, that means the same thing regardless of which property or which market it’s evaluating.

If you’re inside a 45-day window right now, the fastest way to see this in practice is to upload an offering memo and watch it turn into a scored comparison in under five minutes.