🏠 How Property Assessors Value Homes in King & Snohomish County: 2025 Homeowner's Guide

Ever looked at your annual property tax statement and wondered how the county came up with your home’s value? You're not alone.

Whether you live in King or Snohomish County, understanding how assessors value your property can help you plan ahead, challenge inaccurate assessments, and even save on taxes.

Let’s break down how the process works — and how you can stay ahead of the game.

📅 When Do Property Assessments Happen?

In both King County and Snohomish County, property is assessed annually — not just every few years like it used to be. These annual assessments are meant to reflect changes in market conditions and property characteristics, but here's the catch:

🗓️ The official date of valuation is always January 1 of the prior year.
✔ For example: Your 2026 property tax bill is based on your home's market value as of January 1, 2025.

🧠 How Do Counties Determine Your Home’s Value?

Counties use automated valuation models (AVMs) — data-driven systems that analyze sales, market trends, and property characteristics to estimate market value.

👇 Here's What Goes Into the Calculation:

• ✅ Finished square footage

• ✅ Lot size

• ✅ Bedrooms & bathrooms

• ✅ Year built & remodel history

• ✅ Neighborhood sales trends

• ✅ Market data up to 18 months before January 1

• ✅ Condition, upgrades, and other adjustments (only if reported)

⚠️ Important: AVMs rely on accurate tax record data. If the public record is wrong — your valuation might be too.

🛠️ What If the County Gets It Wrong?

In a fast-moving market like the Seattle metro area, AVMs can lag behind or overshoot reality.

🔍 Here are common issues:

• Incorrect square footage

• Outdated remodel or condition info

• Improper comparisons to non-similar homes

• Overestimating market growth near the valuation date

💡 Pro Tip: Check Your Property's Assessed Value Every Year

Don’t wait until tax bills arrive! Be proactive:

1. Compare your home's assessment to nearby sales from late the prior year.

2. Check for errors in the public record on the county assessor’s website.

3. Request a property review or file an appeal if your value is too high.

A 10% overvaluation on a $900,000 home could cost you $750 or more annually in excess property tax.

📈 Get a Free Comparable Market Analysis (CMA)

Want to know how your assessed value stacks up to current market trends? We offer complimentary CMA reports to help you:

• Evaluate if your valuation is fair

• Spot opportunities to appeal

• Stay ahead of rising property taxes

🔎 Resources

King County Assessor’s Office
📍 https://kingcounty.gov/assessor

Snohomish County Assessor’s Office
📍 https://snohomishcountywa.gov/assessor

🗣️ Questions About Your Assessment?

Our real estate team has helped hundreds of local homeowners understand and challenge their valuations. If your home’s value feels inflated — we’re happy to take a look.

📞 Call/Text: 206 489 4920
📩 Email: Team@ReeceHomes.com
📊 Request Free Home Value Report