King County

King County sits at a 2.2% cap rate and a gross rent-to-price ratio of 0.0338, which places it firmly at the appreciation end of the spectrum with almost no current cash-flow case to be made. The investment model is blunt: at a $824,870 purchase price, 20% down, and a 6.85% rate, the monthly mortgage alone runs $4,324. Add $813 in estimated expenses and you are looking at negative $2,814 in monthly cash flow. Cash-on-cash return comes out to -17.8%. That is not a rounding error or a bad submarket pick, it is the market. Year-over-year home prices are actually down 2.25%, so you are not even getting near-term appreciation to offset the carry. An affordability index score of 6 out of 100 confirms what the numbers already show: this is one of the least affordable entry points in the country, ranking 777th out of 1,000 counties nationally and 33rd out of 39 in Washington state.

The buyer this market suits is a long-duration appreciation investor who can absorb a significant monthly loss and is underwriting on a 7-to-10-year horizon, betting that a 2.25-million-person metro with structural housing constraints will compound price appreciation over time. It does not suit a cash-flow buyer under any conventional financing scenario, and it is a poor fit for a value-add operator unless they are acquiring deeply distressed assets at a meaningful discount to the $824,870 median, which is difficult to source at scale in a liquid, institutionally tracked market. If your thesis requires the property to pay for itself, King County will not deliver that. If your thesis is parking capital in a large, supply-constrained coastal metro and accepting short-term losses to capture long-term price growth, the market logic is at least coherent, though the negative 2.25% price movement over the past year is a reminder that even appreciation markets can stall.

Combined monthly property tax and insurance on a median-priced asset runs approximately $818, using Washington's state-average effective tax rate of 0.98% (per Tax Foundation 2024 data) alongside an insurance rate of 0.21%. That works out to roughly $8,084 in annual property tax and $1,732 in annual insurance. The 0.98% tax rate is flagged as normal rather than punitive, so it is not the primary drag on returns here, but at $818 per month it is still a real line on the pro forma that compounds the already-negative cash-flow picture. The honest caveat that applies to all state-average estimates: actual county and township rates vary, and King County's assessed values are high enough that even small rate differences translate into meaningful dollar amounts. Underwrite to your specific parcel.

The main risks here are concentration and valuation sensitivity. A single county with 2.25 million people and a median home price north of $824,000 means the investor base is competing for the same tier of assets, liquidity cuts both ways, and any softening in the tech-adjacent employment base would transmit quickly to both rents and prices. The current year-over-year price decline of 2.25%, while modest in absolute terms, signals the market is not immune to rate-driven demand compression. No vacancy or crime data is provided here, so no inference is drawn on those fronts, but an investor underwriting King County should model at least one to two years of further price softness before assuming the appreciation thesis reasserts itself.

Against its neighbors, King County is the most expensive and the worst-performing investment market by every metric provided. Snohomish County to the north prices at $739,453 median with a rent-to-price ratio of 0.0349 versus King's 0.0338, and carries an overall score of 37 versus King's 30. Island County comes in at $623,534 median, a 0.0388 rent-to-price ratio, and an overall score of 39. Whatcom County and Chelan County both post rent-to-price ratios above 0.040, with lower entry prices of $600,648 and $526,792 respectively, and both score 40 overall. Even San Juan County, which is priced slightly higher at $865,228, ties King at an overall score of 30 and is a niche vacation-rental market with a very different risk profile. The case for choosing King over any of these neighbors rests entirely on belief in the Seattle metro's long-run price trajectory, not on income return. If that conviction is strong and the investor has the balance sheet to absorb sustained negative cash flow, King County is the right address for that specific bet. If the investor wants better income coverage while staying in Washington, Whatcom or Chelan offer meaningfully better ratios at lower basis, and Island County threads between the two on price and income.