Inspection Finding Frequency Comparison
The following comparison draws on inspection industry data and regional inspector observations. Frequency represents approximately how often an issue appears as a significant finding in inspection reports.
| Issue Category | Seattle Metro | National Average | Notes |
|---|---|---|---|
| Crawlspace moisture | 55-65% | 20-25% | Seattle's constant rain and humidity nearly universal |
| Roof concerns | 50-55% | 40-45% | Constant moisture and moss accelerate deterioration |
| Wood decay/rot | 45-50% | 20-25% | Moisture enables decay faster than dry climates |
| Exterior paint/siding | 50-55% | 35-40% | Constant moisture causes faster deterioration |
| Foundation concerns | 30-40% | 25-30% | Higher for hillside properties specifically |
| HVAC issues | 30-35% | 35-40% | Mild climate means less stress on heating/cooling |
| Electrical concerns | 35-40% | 35-40% | Similar to national; knob-and-tube in older homes |
| Radon above action level | 8-12% | 12-15% | Lower than national; still worth testing |
| Termite/WDO activity | 15-20% | 25-30% | Lower than warm/humid regions |
Seattle's Highest-Impact Differences
Several categories show dramatically different patterns in Seattle compared to national norms.
Crawlspace Moisture
This is Seattle's defining inspection difference. While national data shows crawlspace moisture concerns in roughly 20-25% of inspections, Seattle rates approach 55-65%. The combination of 150+ rain days annually, high humidity, and traditional vented crawlspace construction creates conditions where moisture problems are essentially expected.
What would be a significant finding elsewhere is baseline reality in Seattle. Buyers should evaluate not whether moisture exists, but how severe it is and whether proper management (encapsulation, dehumidification) is in place.
Wood Decay and Rot
Constant moisture accelerates wood decay. Seattle inspections find significant wood rot in 45-50% of inspections versus roughly 20-25% nationally. This affects exterior trim, porch components, window frames, and structural elements where water contact occurs.
Well-maintained homes can minimize rot, but the climate works constantly against all wood components. Paint schedules, flashing integrity, and moisture management all affect how quickly decay progresses.
Roof and Exterior Deterioration
Seattle roofs face constant water contact and near-universal moss growth. A composition roof that might last 25 years elsewhere typically lasts 18-22 years in Seattle. Inspections find significant roof concerns in 50-55% of reports versus about 40-45% nationally.
Exterior paint fails faster, siding deteriorates sooner, and constant moisture finds every gap in the building envelope. This isn't defective construction—it's the reality of building in a wet climate.
Where Seattle Performs Better
Seattle's mild climate provides advantages that offset its moisture challenges.
HVAC System Longevity
Seattle's mild temperatures—rarely above 90°F in summer or below 25°F in winter—reduce stress on HVAC systems. Neither heating nor cooling works as hard as in extreme climates. HVAC concerns appear in 30-35% of Seattle inspections versus 35-40% nationally.
Systems often last longer than in regions with brutal summers or harsh winters.
Lower Radon Risk
Seattle's geology produces lower radon levels than many regions. While testing is still recommended, only 8-12% of Seattle homes test above the EPA action level versus 12-15% nationally and 40-50% in high-radon areas like Denver or certain Midwest regions.
Reduced Termite Pressure
Seattle's cool, wet climate discourages termites compared to warm, humid regions. While carpenter ants and other wood-destroying organisms exist, termite damage appears in 15-20% of Seattle inspections versus 25-30% nationally and 45-55% in the South.
Regional Cost Comparisons
Seattle generally falls in the high-cost category for both inspections and repairs.
| Service/Repair | Seattle Average | National Average | Lower Cost Markets |
|---|---|---|---|
| Standard home inspection | $500-700 | $350-550 | $300-450 (Midwest, South) |
| Crawlspace encapsulation | $8,000-15,000 | $5,000-12,000 | Similar where applicable |
| Roof replacement | $12,000-20,000 | $8,000-15,000 | $6,000-12,000 (Midwest) |
| Sewer line replacement | $8,000-20,000 | $6,000-15,000 | $5,000-12,000 (low-cost areas) |
| Structural engineering | $400-600 | $300-500 | $250-400 (rural areas) |
| Rewiring (older home) | $12,000-20,000 | $8,000-15,000 | $6,000-12,000 (low-labor areas) |
How Seattle Compares to Similar Markets
Seattle shares characteristics with other Pacific Northwest markets but has distinct patterns.
Seattle vs. Portland
Very similar climate and housing stock. Both face comparable moisture challenges. Portland has slightly lower costs for labor and materials. Both have significant Craftsman bungalow inventory with similar age-related issues.
Seattle vs. San Francisco
San Francisco has much higher costs, significant seismic considerations, and less constant moisture. Both have older housing stock requiring ongoing maintenance. San Francisco's fog creates different moisture patterns than Seattle's rain.
Seattle vs. Denver
Opposite moisture challenges—Denver is semi-arid with radon concerns; Seattle is wet with crawlspace concerns. Denver has severe foundation issues from expansive clay; Seattle has hillside drainage issues. Denver roofs face hail; Seattle roofs face moss and constant water.
What These Differences Mean for Buyers
Understanding Seattle's inspection patterns helps set appropriate expectations:
Expect Moisture Findings
Crawlspace moisture, exterior rot, and water-related issues will appear in most Seattle inspections. The question isn't whether they exist, but how severe and how well-managed they are. Budget for moisture remediation as a likely ownership cost.
Plan for Shorter Component Life
Roofs, paint, and exterior components wear faster in Seattle's climate. Budget for more frequent replacement and maintenance than national averages suggest.
Appreciate the Mild Climate Benefits
Seattle homes avoid freeze-thaw damage, extreme heat stress, and significant pest pressure that plague other regions. The mild climate is easier on many systems even as moisture creates its own challenges.
Consider Hillside Complexity
Seattle's hills add drainage and foundation considerations absent in flat markets. If buying on a slope, evaluate retaining walls and drainage carefully.