What Is Vacancy Rate
Vacancy rate is the percentage of rentable space sitting empty at a given time. For a 10-unit apartment building with 2 vacant units, the vacancy rate is 20%. Assessors use this figure to calculate income-producing property values because a building that's half-empty generates half the revenue of a fully-occupied one.
Why It Matters in Assessment Appeals
Assessors often use the income capitalization approach to value rental properties. This method divides annual net operating income by a capitalization rate to estimate value. Vacancy rate directly reduces the numerator in that calculation. If an assessor assumes 5% vacancy but your property runs at 15%, you're overstating income and therefore overstating value.
On your tax assessment appeal, vacancy rate becomes your lever. A Board of Review hearing focuses partly on whether the assessor's appraisal methods match local market conditions. If comparable properties in your market show 12% vacancy and your assessment assumes 3%, that's a factual error you can challenge with evidence.
How Assessors Use Vacancy Rate
- Market-wide rates: Most jurisdictions apply a standard vacancy assumption based on recent market data. This typically ranges from 3% to 10% depending on the market and property type. Check your assessor's documentation to see what assumption they used.
- Individual property history: Some assessors review a specific property's historical occupancy. If you have 18 months of lease records showing 8% average vacancy, bring those to your hearing.
- Income calculation: Vacancy rate reduces potential gross income to arrive at effective gross income, which then flows into net operating income calculations.
- Comparable sales adjustment: When comparing your property to recent sales, vacancy rates of the comparables matter too. A property that sold while 20% vacant is worth less than one that sold fully occupied, all else equal.
Gathering Evidence for Your Appeal
Document actual vacancy in your property for at least 12 months. Lease records, rent rolls, and tenant move-in/move-out dates establish your true vacancy rate. If you're seeking an exemption or special classification, this documentation matters even more.
Research market-wide vacancy rates for similar properties in your area. Many commercial real estate firms publish quarterly vacancy surveys by property type and neighborhood. Bring these to your Board of Review hearing to show the assessor's assumptions diverge from market reality.
If the assessed value assumes lower vacancy than comparable properties actually experience, you have grounds to argue the assessment is inflated.
Common Questions
- Can I claim vacancy rate if units are temporarily vacant due to turnover? Yes, but temporary turnover is expected and already baked into market vacancy rates. What matters is your long-term average over 12 months, not a single vacant unit in January. The assessor should use market-wide vacancy assumptions, not assume your property stays perpetually full.
- How do I know what vacancy rate the assessor used? Request the property's appraisal report from your local assessor's office. It should show the income approach calculation and state the vacancy assumption explicitly. If it doesn't, ask in writing or bring the question to your Board of Review hearing.
- Does a 10% vacancy rate reduce my assessment by 10%? Not directly. The reduction depends on where vacancy sits in the income calculation. A 10% vacancy rate on potential gross income becomes part of the effective gross income figure, which reduces net operating income. That reduction then gets capitalized. The exact impact depends on your property's operating expense ratio and the cap rate used.