Grundy County presents a narrow underwriting tension: Zillow’s 2026-06 county median home value is $215,826, up 4.04% year over year, while FHFA’s annual 2025 repeat-transaction HPI rose 2.81%. Those observations use different vintages and methods, so they should not be blended into a single growth rate. The county record supports an appreciation signal, but not a cash-flow case. An investor who can validate local rents and flood costs should investigate; a yield-first rental underwriter should remain cautious.
Market rent is not published, so gross yield cannot be computed. HUD’s two-bedroom FMR is $925 per month, but it is a payment standard rather than asking rent and cannot fill that gap. The effective property-tax rate is 0.38%, with a median annual tax of $586. The modeled climate-loss ratio is 0.14% of building value per year; because inland flood is the dominant hazard, parcel-level flood exposure, insurance, deductibles, and mitigation must be checked before treating taxes as the main carrying-cost issue.
Demand evidence is mixed. QCEW 2025 shows 2,120 annual average covered jobs located in the county, while the average covered-worker weekly wage is $751 and fell 0.92% from the prior annual average. Trade, transportation, and utilities is the largest disclosed private supersector, but that industry is not the whole economy and QCEW is not resident employment. Net migration was 74 tax-return households; average AGI was $70,959 for incoming movers versus $40,796 for outgoing movers. Of 145 purchase mortgages, 18 went to investors, a 12.41% share. That combination supports checking demand and buyer competition, not assuming either.
The supplied Realtor.com inventory fields are not published, so there is no MLS evidence here on median asking price, active supply, marketing time, price reductions, or pending listings; none would be a closed-sale measure anyway. The record also lacks market rent, vacancy, operating expenses, financing, insurance quotes, parcel-level flood exposure, and property condition. Those gaps prevent conclusions about gross yield, stabilized cash flow, buyer demand, or all-in flood affordability. Next checks are comparable leases or a rent roll, property-level flood and insurance review, and separate closed-sale and MLS verification; keep Zillow and FHFA as distinct series.