In 78228, the direct rolling-three-month ZIP resale observation presents a notably softer for-sale setting than the rent index alone would imply. Median sold price was $179,859, down 16.34% year over year, while 55 homes sold and median marketing time reached 70 days. Inventory stood at 121 homes, equivalent to 6.8 months of supply. The average sale-to-list ratio was 92.13%, only 5.67% of sales closed above list, and 25.92% went off market within two weeks. Those are resale-market signals only: they describe completed home sales, listings, and marketing conditions rather than rental transactions, apartment availability, or property-level rental economics.
The current Zillow ZIP asking-rent index is $1,216 per month, with a 2.07% year-over-year increase. Zillow ZORI is a typical observed asking-rent index blended across rental types, so it is not a lease-specific quote or a survey of occupied homes. As wider-context benchmarks, San Antonio city has a $1,381.64 rent context value, Bexar County has a $1,389 context value, and the San Antonio-New Braunfels metro has a $1,416 context value; each is a broader geography, not a substitute for the ZIP reading. The ZIP’s lower asking-rent index therefore establishes relative positioning against those contexts, without identifying a cause or an individual unit’s rent.
The longer Zillow history remains positive but has slowed. Exact same-month annualized change was 2.07% over 1 year, 3.13% over 3 years, and 5.14% over 5 years. Recent direction thus confirms continued rent growth, yet it does not confirm the stronger pace shown by the longer path. Monthly-return variability annualized to 4.73%, consistent with the high-variability history classification and reducing confidence that one current index value fully represents a stable trajectory. Separately, the largest peak-to-trough drawdown was 7.50%, showing that past asking-rent movement included meaningful reversals. Coverage was 97.78%. Transparent national discovery ranks among history-eligible ZIPs were 1,212 for momentum, 2,792 for stability, and 2,194 for the balanced measure, where lower ranks are higher. These are backward-looking discovery measurements, not forecasts or investment recommendations.
The local bedroom ladder should be read as modelled estimates, not measured bedroom rents. Scaling ZIP ZORI with the local HUD ladder produces estimates of $917 for a studio, $1,007 for a one-bedroom, $1,216 for a two-bedroom, $1,565 for a three-bedroom, and $1,814 for a four-bedroom. HUD FMR or SAFMR is an administrative bedroom-specific standard, not an asking-rent measure, which is why the ladder provides a scaling device rather than rental comparables. By contrast, the matched ACS ZCTA median gross rent is $1,032, or 17.83% below the Zillow asking-rent index. ACS is a five-year survey of occupied renter homes and includes selected utilities, so that gap compares distinct universes rather than proving that one source is wrong.
The 30% required-income screen translates the current asking-rent index into $48,640 of annual income under that arithmetic convention. This is not advice, an applicant qualification rule, or evidence that a household can obtain a particular home. The matched ZCTA median household income is $52,976, making the index-based screen equal to 27.54% of that median income before considering household composition, utilities, concessions, or lease terms. In the ACS 2024 five-year renter-household survey, 53.86% of renter households were burdened at 30% or more of income. That burden measure describes surveyed households, not the payment experience of a specific renter or the affordability of a particular available unit.
The Census housing profile supplies useful scale but requires a geography caution. The five-digit label is both a Zillow ZIP market identifier and the matched Census ZCTA; a ZCTA is a statistical area and is not identical to a USPS delivery ZIP. The ZCTA contained 21,432 housing units, with a 9.60% vacancy rate and a 40.66% renter share. Its stock included 15,741 single-family units and 1,232 units in large multifamily structures. These counts help frame the mix represented in the survey, while the vacancy rate remains an area-level estimate rather than proof that any specific rental is available, competitively priced, or vacant for the same reason as another unit.
The central tension is that ZIP asking rent has continued upward at a reduced pace while the direct resale record shows lower sold prices and weaker sale-to-list outcomes. The annualized ZIP ZORI divided by median sold price produces an 8.11% cross-source screening ratio. It is neither a cap rate, net return, expected return, nor property yield because it excludes property-specific income, expenses, financing, taxes, insurance, maintenance, vacancies, and transaction differences. The resale evidence challenges any simple reading of positive rent history as broadly stable market strength: resale liquidity, price direction, and rental asking rents are separate observations that can move differently. Likewise, the household income screen sits below its arithmetic threshold while the surveyed renter burden remains elevated.
Decision use depends on testing the address-level facts that these aggregate measures cannot supply. Confirm the actual advertised rent, bedroom count, lease duration, concessions, utility inclusions, move-in timing, and comparable currently available rentals before treating the modelled ladder as relevant. For a home under consideration for sale or purchase, verify the specific listing history, recent closed sales used for comparison, contract terms, physical condition disclosures, and recurring ownership obligations rather than applying the ZIP screening ratio to the property. Zillow, ACS, HUD, and Redfin answer different questions on different populations and time windows. The useful closing question is whether the particular unit’s documented all-in terms still fit the household’s circumstances after those source boundaries are respected.