What Is Physical Depreciation
Physical depreciation is the loss in property value caused by wear, tear, structural damage, and aging of building components. Assessors apply percentage deductions to your property's replacement cost based on the condition of the roof, foundation, mechanical systems, interior finishes, and overall structural integrity.
In property tax assessment, physical depreciation appears in the cost approach to valuation, where assessors calculate: land value plus replacement cost of improvements minus depreciation. The key distinction: physical depreciation reflects actual condition, not market perception. A 30-year-old roof in poor condition gets depreciated differently than a recently replaced one, regardless of comparable sales in your area.
Depreciation Schedules and Assessment Ratios
Most county assessors use depreciation schedules that apply percentage reductions based on building age and condition. These vary significantly by jurisdiction. Some counties use straight-line depreciation (dividing effective age by total economic life), while others use accelerated schedules that front-load depreciation in early years.
The critical number: assessment ratio. If your county assesses at 50% of market value, an assessor might estimate your home's replacement cost at $400,000, then apply 25% physical depreciation ($100,000 reduction) before factoring in the assessment ratio. This compounds, which is why accuracy matters.
When you challenge an assessment at a board of review hearing, you're often challenging the depreciation percentage itself. If the assessor claims 20% depreciation on a 15-year-old home with deferred maintenance, comparable sales data showing similar homes selling above assessed values can expose overestimated depreciation.
Distinguishing Physical From Other Depreciation
Physical depreciation differs critically from functional obsolescence (outdated design, poor floor plan, inadequate systems) and economic obsolescence (neighborhood decline, proximity to highways, zoning changes). A kitchen with original 1970s cabinets shows physical wear, but if those cabinets still function, that's primarily functional obsolescence. A commercial building adjacent to a closed factory exhibits economic obsolescence unrelated to its physical condition.
Assessors sometimes conflate these. During appeals, you can separate them: "The HVAC system needs replacement (physical), but this doesn't affect comparable sales in functional, economically sound neighborhoods." This specificity strengthens your position.
Documentation for Appeals
To challenge inflated physical depreciation at a board of review hearing, gather:
- Inspection reports or engineering assessments documenting actual condition of major systems (roof, foundation, electrical, plumbing, HVAC)
- Recent repair or replacement receipts proving deferred maintenance doesn't exist where the assessor claims it
- Comparable sales of similar-age homes that sold at prices above assessed value (suggesting depreciation is overstated)
- Your assessor's own depreciation schedule and methodology (request this through FOIA if necessary)
- Photos showing exterior and systems in serviceable condition
Appraisers often use the Marshall Valuation Service or ARES Cost Handbook, which provide standardized depreciation guidelines. If your assessor used an outdated schedule or applied depreciation inconsistently across your neighborhood, that's actionable evidence.
Common Questions
- Can I claim physical depreciation for deferred maintenance the assessor hasn't documented? No. The assessor values current condition, not potential repairs. However, if you've already made repairs or replacements (documented with receipts), the assessor should reflect that by reducing depreciation. If they haven't, that's a specific appeal point.
- How old does a property need to be before physical depreciation applies? Immediately. A new building has zero or near-zero depreciation. A 5-year-old home typically shows 5-10% depreciation depending on local schedules. By year 20-30, depreciation may reach 25-35%. After 50+ years, it plateaus (property rarely depreciates below 40-50% of replacement cost in most jurisdictions).
- If I disagree with the assessor's depreciation percentage, how do I prove my number? Use comparable sales adjusted for condition differences, or hire an MAI appraiser to provide an independent valuation. At a board of review hearing, the burden falls on you to show the assessed value exceeds fair market value. If comparables support a lower value, that indirectly proves depreciation was overstated.