VACANCY & PROPERTY TAX

Property Tax on a Vacant Commercial Building

Vacancy is real economic loss — but the tax bill rarely reflects it. When a building loses tenants, assessors often keep valuing it as if every square foot were filled at pro-forma rent. Here is how to push back.

THE CORE PROBLEM

Vacancy Is Real Economic Loss the Assessor Often Ignores

When a commercial building sits empty — fully or partially — the cash flow stops, but the property tax bill does not. Mass-appraisal models used by most county assessors stabilize value as if every property were running at the sub-market average vacancy rate, often 5-10%. A 60%-vacant office tower or a single-tenant retail box that just went dark gets taxed against a hypothetical version of itself that does not exist. The income approach, applied honestly, has to reflect the property as it actually is on the assessment date — not the property the assessor wishes it were.

An honest income approach starts with actual rent rolls, then layers in real vacancy plus collection loss, real leasing concessions (free rent, TI allowances, brokerage commissions), and a market-derived cap rate that prices in the lease-up risk a buyer would actually demand. The gap between a stabilized as-if-leased value and a vacancy-adjusted value can easily be 30-50% on a partially leased building, and even more on a single-tenant property where the tenant has gone dark. That gap is your appeal — and it is also the reason a clear-eyed look at assessed value versus market value almost always shows vacant and partially leased buildings on the over-assessed side of the line.

Mass-appraisal stabilizes value at sub-market vacancy — your reality may be 40-100% empty

Effective rent is the right input — face rent minus concessions, not asking rent

Collection loss on a struggling tenant is real and belongs in the income approach

Cap rates on vacant or partially leased assets must price in lease-up risk

Want to see how vacancy interacts with broader assessment errors? Our commercial property tax assessment guide walks through every input assessors use — and where each one tends to break.

Commercial property owner reviewing vacancy data on a partially leased office building tax assessment

WHERE THE GAP COMES FROM

Why Mass-Appraisal Misses Vacancy

County assessors value tens of thousands of properties every cycle using statistical models that lean on submarket averages, not property-specific facts. That works for stable, fully leased buildings. It collapses for vacant ones. The same patterns show up across Michigan, Ohio, and Indiana, and they are exactly the patterns a well-prepared appeal can dismantle.

01Models trend last year's value forward instead of revaluing on assessment-date facts

02Prior-year occupancy schedules get carried over even when tenants have since vacated

03Sub-market average vacancy is applied uniformly, ignoring property-specific lease-up risk

04Distressed and gone-dark comparable sales are dismissed as 'non-arm's-length' or outliers

05Sale-leaseback transactions with above-market rent quietly contaminate the comp set

06Functional and external obsolescence claims get waved off without a real cost-to-cure analysis

WHEN IT APPLIES

Common Vacancy Scenarios We Appeal

Ground-up vacant new construction. The certificate of occupancy is fresh, leasing has barely started, and the assessor is already valuing the building at stabilized pro-forma. Real lease-up timelines and concession costs change the math.

Partially leased office or retail. Anchor tenant moved out, in-line tenants are turning over, and you are stuck carrying a stabilized assessment while running 40-60% occupancy. A vacancy-adjusted income approach typically wins material reductions here.

Single-tenant gone dark. The operator vacated, the build-to-suit features become functional obsolescence, and dark store comparable sales become the controlling evidence — often producing 30-50% reductions on retail, pharmacy, and big-box assets.

NNN tenant just vacated. The landlord absorbs the full tax bill for the first time. Fast filing matters — the appeal cycle, not the lease cycle, drives how quickly the assessment can be corrected to post-vacancy reality.

Empty space costs you twice.

Once on the rent roll.

Once on the tax bill.

DOCUMENTING VACANCY

How to Document Vacancy for an Appeal

Vacancy claims live or die on documentation. Tribunals reward owners who arrive with a clean evidence package and dismiss arguments that rely on assertion alone.

Pull Occupancy Schedules & Leasing History

Start with rent rolls dated to the assessment date, the trailing twenty-four months of occupancy schedules, all leases (including amendments and side letters), and a written leasing-activity log. Concessions, free rent, and tenant-improvement allowances belong in the file because they prove effective rent is below face rent. Our appeal evidence checklist lists every document tribunals expect to see.

Get a Broker Opinion of Value & Marketing Proof

A broker opinion of value (BOV) from a credible local broker carries weight, especially when paired with the actual marketing materials, listing agreements, and tour logs from the property. The story you want to tell is "we tried to lease this space at market rents and the market said no" — and a BOV documents exactly that. Pair it with broker comments on absorption, days-on-market, and required concessions in the submarket.

Build a Vacancy + Concession-Adjusted Income Approach

Reconstruct the income approach using the property as it actually exists on the assessment date: actual rents on occupied space, market rents on vacant space, a property-specific vacancy and collection loss, lease-up costs amortized appropriately, and a cap rate that priced in the risk a real investor would demand. Standards for this analysis are well established under USPAP, and the same framework applies whether you are appealing in Michigan, Ohio, or Indiana.

Identify Distressed & Gone-Dark Comparable Sales

For single-tenant and big-box assets, distressed comps are not optional — they are the case. Pull recent arm's-length sales of similarly vacant buildings in the submarket, document any retrofit or repurposing the new owner had to undertake, and adjust for differences in size, age, location, and remaining functional life. This is the same evidentiary backbone behind dark store theory appeals, and it travels well to traditional vacancy claims on shopping centers and industrial buildings as well.

WHAT CHANGES

Stabilized Assessment vs. Vacancy-Adjusted Assessment

The same building, the same rent roll, two very different tax bills — depending on whether the assessor accepts vacancy as real.

When Vacancy Is Properly Reflected

Income approach uses actual occupancy and effective rents

Cap rate prices in lease-up risk and concession burden

Distressed comparable sales control gone-dark valuations

Functional obsolescence and external obsolescence are quantified

Assessment drops 20-50%, with savings recurring every year the lower value holds

When the Assessor Stabilizes As-If-Leased

Tax bill assumes pro-forma occupancy you cannot achieve

Carrying costs on the empty space compound the cash drain

Each new assessment cycle re-anchors on the inflated baseline

Refinancing and disposition pricing get distorted by the bad value

Triple-net pass-throughs blow up tenant relationships when finally reset

STATE-SPECIFIC NUANCES

How Vacancy Interacts With State-Specific Rules

Vacancy claims travel — but the procedural and substantive rules differ across the three states we cover. Learn the basics for Michigan, Ohio, and Indiana, and pair them with our filing deadline guide. Petition guidance from the Michigan Department of Treasury on supporting documentation is available here.

Michigan — dark store theory is well established at the Tax Tribunal; vacancy + functional obsolescence claims for single-tenant assets are routinely accepted with proper evidence

Ohio — the triennial reappraisal cycle means a vacancy that hits mid-cycle can sit on a stale stabilized value for years unless a Board of Revision complaint is filed by March 31

Indiana — the circuit breaker tax cap can limit the year-one cash savings even when the assessment is materially reduced; multi-year strategy matters

All three states — vacancy claims are strongest when occupancy schedules are dated to the assessment date and concessions are documented in writing

Sale-leasebacks and above-market rents must be flagged in the comp set or the assessor's value gets propped up by transactions that are not really arm's-length

Long-vacant ground-up new construction often qualifies for both vacancy adjustments and external-obsolescence claims

Vacancy reduces the property's actual income and therefore its real market value, but assessors using mass-appraisal models often value commercial buildings as if they were stabilized at sub-market average occupancy. That means an empty 80,000-square-foot office that is generating zero income can still be carrying an assessment built on a hypothetical 90% occupancy at pro-forma rents. The result is an over-assessed property whose tax bill bears no relationship to its actual cash flow. The fix is a vacancy-adjusted income approach that reflects real occupancy, real concessions, and real lease-up risk — see our property tax appeal process guide for how that argument gets presented.

The strongest vacancy package combines documentary and market evidence. On the property side, you need rent rolls or occupancy schedules dated to the assessment date, leasing history showing how long units sat vacant, broker listing agreements, and marketing collateral showing genuine effort to lease the space. On the market side, pull comparable sales of similarly vacant or partially leased buildings, broker opinions of value, and any independent appraisals. Our appeal evidence guide breaks each category down. If concessions, free rent, or tenant improvement allowances were granted to fill space, those numbers belong in the package because they prove effective rent is below face rent.

Yes — and partially leased buildings are some of the most appealable assets in the inventory. Assessors frequently apply a stabilized vacancy assumption (often 5-10%) regardless of what is actually happening at your property, so a building that is 55% leased gets taxed as though it were 92% leased. The income approach has to reflect actual contract rents on occupied space, market rents on vacant space, a property-specific vacancy and collection loss, and the cost of leasing concessions to get the rest of the building filled. A market-derived cap rate applied to that adjusted NOI usually produces a value far below the assessor's number, especially when paired with true market value evidence from comparable sales.

A single-tenant building where the operator has gone dark is the textbook vacancy case, and it overlaps directly with dark store theory. Once the tenant leaves, the build-to-suit features that made the property valuable at full occupancy become functional obsolescence — the next user has to absorb significant retrofit costs to make the building work for them. Distressed comparable sales of similar gone-dark assets become the controlling evidence, often supporting a 30-50% reduction in assessed value. This argument is especially strong on big-box retail, pharmacies, fast food, and freestanding bank branches across Michigan, Ohio, and Indiana.

When the tenant on a triple-net lease vacates — whether through bankruptcy, non-renewal, or going dark — the landlord absorbs the entire tax burden for the first time, and the assessment that looked tolerable as a pass-through suddenly becomes painful out-of-pocket. That tax bill is rarely a fair reflection of what the building is worth in its newly vacant state. See our guide on triple net lease property taxes for the standing and reconciliation issues. The right response is usually a fast appeal grounded in the post-vacancy income approach plus comparable sales of similarly empty single-tenant assets.

They should — and on a properly run appeal, they do. Hold-vacancy analysis quantifies the real cost of carrying an empty building: lost rent, ongoing operating expenses, debt service, taxes, insurance, security, and the time value of money during the lease-up period. Even at sub-market average vacancy assumptions, a building with a known long lease-up cycle is worth materially less than a stabilized comp. Assessors who refuse to consider hold-vacancy economics are essentially taxing income that nobody is collecting, and tribunals — especially the Ohio Board of Revision and Michigan Tax Tribunal — increasingly accept this analysis when it is properly documented.

Each state handles vacancy differently. Michigan's Tax Tribunal has a developed body of case law on dark stores and functional obsolescence, and the May 31 commercial filing deadline is hard. Ohio's triennial reappraisal cycle means a vacancy that hits between cycles can sit on a stale assessment for years unless you file a Board of Revision complaint by March 31 — and Ohio assessors often anchor on pre-vacancy stabilized values. Indiana's annual trending plus the circuit breaker tax cap creates a different math: even when the assessment overstates value, the cap may limit the year-one tax savings, which is why knowing your filing deadlines and pairing the vacancy claim with a multi-year strategy matters. A free assessment review will tell you which path your property qualifies for.

RELATED RESOURCES

Continue Learning About Commercial Property Tax Appeals

Dark Store Theory — How gone-dark valuations work for big-box and single-tenant assets

Cap Rates & Property Taxes — How rate selection drives income-approach values

Property Tax Appeal Evidence — The full documentation checklist for any appeal

Property Tax Appeal Process — Step-by-step from notice to decision

Triple Net Lease Property Taxes — Who pays when an NNN tenant vacates

2026 Property Tax Appeal Deadlines — MI, OH, and IN filing windows

Office Property Tax Appeals — Vacancy is the dominant driver in office assessments

Retail Property Tax Appeals — Anchor and in-line vacancy in shopping centers

SELECT YOUR STATE

Find Your State's Appeal Process

Property tax appeal procedures vary by state. Choose your state below for a detailed guide to the appeal body that handles your commercial property tax appeal.

Michigan

Tax Tribunal

Michigan's statewide tax appeal body. Strict May 31 / July 31 filing deadlines depending on property type.

Michigan Tax Tribunal

Ohio

Board of Revision

Ohio's county-level first step for property tax appeals. March 31 filing deadline every year.

Ohio Board of Revision

Indiana

PTABOA

Indiana's county Property Tax Assessment Board of Appeals. Form 130 filed within 45 days of notice.

Indiana PTABOA

APPEAL DEADLINE

Don't Let the Deadline Decide for You

Once the filing window closes, you're locked in for another year — even if your taxes are wrong.

Submit your details now, and we'll tell you where you stand.

Nearly 20 years of experience

Michigan, Indiana & Ohio

Paid only if we save you money

State capitol building representing property tax appeal deadlines and government proceedings