Contra Costa County

Contra Costa County sits at a 2.72% cap rate on a $789,908 median purchase price, generating an estimated $2,754 in monthly rent against $4,141 in mortgage payments at 6.85%. The gross rent-to-price ratio comes in at 0.042, which is thin but slightly better than several Bay Area neighbors. None of that changes the bottom line: at a 20% down payment, this market produces negative $2,351 in monthly cash flow and a cash-on-cash return of -15.53%. The affordability index sits at 34, meaning the median household income of $120,020 covers well under half of what ownership actually costs here. Home prices are also down 4.0% year-over-year, so you're not being compensated on the appreciation side either, at least not recently. The overall score of 37 out of 100 ranks Contra Costa in the 3rd national percentile across 1,000 counties evaluated, and 35th out of 58 California counties, putting it in the bottom half of an already expensive state.

This market does not suit a cash-flow buyer under conventional financing. The numbers simply don't support it: a $157,982 down payment produces a -15.53% cash-on-cash return, which is a material capital destruction scenario before any capital expenditure or vacancy. An appreciation buyer might find a theoretical case here given the county's proximity to the San Francisco Bay Area job core and a median income base of $120,020 that supports rental demand, but with prices already off 4.0% year-over-year and a cap rate of 2.72%, you're relying entirely on a recovery thesis with no income cushion while you wait. The most plausible use case is a well-capitalized value-add operator who can either force appreciation through repositioning or bring significant equity to compress leverage costs, but even then, an entry price near $790,000 leaves limited margin.

The tax and insurance picture is a modest relative tailwind by California standards. The combined monthly tax and insurance burden runs $592, using a state-average effective property tax rate of 0.73% and an insurance rate of 0.17%. Those figures are already baked into the $964 estimated monthly expense load and the overall cash flow calculation. The 0.73% effective rate carries a "normal" flag, meaning it doesn't stand out as a compounding problem in either direction, but as always, the state-average estimate is exactly that: an estimate. County and township rates vary, and Proposition 13 dynamics mean your actual assessed-value trajectory depends heavily on acquisition timing and reassessment exposure. Confirm the specific parcel-level tax burden before closing, not after.

The primary risk here is structural, not cyclical. California's regulatory environment, including rent control in multiple Contra Costa cities such as Richmond, layered tenant protections, and eviction restrictions, creates operational friction that compounds the already compressed cap rate. A 2.72% cap rate has no room to absorb vacancy, problem tenants, or a rent rollback scenario. The county's population of 1.16 million provides scale and demand diversity, but concentration risk is real in the sense that the entire investment thesis depends on the Bay Area tech and professional employment base remaining intact. There is no secondary economic engine to cushion a significant regional employment contraction.

Compared to the five neighboring counties provided, Contra Costa offers slightly better rent-to-price ratio than San Francisco (0.042 vs. 0.035) at a substantially lower entry price ($790K vs. $1.25M), but both share the same overall score of 37. Ventura and Santa Barbara counties come in at roughly 0.041 rent-to-price with overall scores of 36, meaning they offer comparable yield ratios at higher entry points and without the specific Bay Area regulatory layer. Sonoma County is marginally cheaper at $769,171 median with a 0.041 ratio and scores 35, making it a near-identical trade but with different geographic demand dynamics. Trinity County at $245,830 median and an overall score of 36 is a different asset class entirely: rural, low-liquidity, and missing the rental income data needed to evaluate it seriously. Contra Costa makes the most sense over these neighbors specifically if your thesis is Bay Area rental demand and you need the highest rent-to-price among the Bay-adjacent options at the lowest absolute price point. If your thesis is cash flow, none of these five neighbors solve the problem, and you should be looking outside California entirely.