Multi-Tenant Office Building Overassessment in Texas: Vacant Suites, Phantom Rents, and Winning Tax Protests

Multi-tenant office buildings represent one of the largest categories of commercial real estate in Texas. From the 30-story Class A towers in downtown Dallas and Houston to the mid-rise and garden office parks scattered across DFW, Austin, San Antonio, and every secondary Texas market, office real estate generates enormous tax bills. Yet this asset class is simultaneously one of the most systematically overassessed categories in the state.

The problem is structural and predictable. Texas appraisal districts value multi-tenant office buildings using an income approach that relies on three assumptions: (1) what the building will ultimately lease for when fully occupied, (2) what the effective vacancy rate will be at stabilization, and (3) what cap rate justifies the building’s value. In 2026, most appraisal districts are getting all three assumptions wrong, and they are systematically overvaluing office property across Texas.

This is not a regional problem. Office overassessment occurs in Dallas, Houston, Austin, San Antonio, and in the secondary markets of Plano, Arlington, Frisco, Lewisville, Round Rock, and beyond. The overassessment gap has only widened as the office market has fundamentally shifted in the past 24 months. Understanding why appraisal districts are overvaluing office, how to identify overassessment in your own building, and what evidence wins office property tax protests is now essential knowledge for any commercial property owner in Texas.

The Texas Office Market Reality vs. Appraisal District Assumptions

To understand office overassessment, you must first understand what happened to the Texas office market between 2019 and 2026.

In 2019, Texas’s major metropolitan areas were experiencing a period of strong office market fundamentals. Vacancy rates in major markets averaged 8% to 12%. Rents were stable or rising. Tenant demand was strong. New construction was aggressive but not excessive relative to demand. Appraisal districts calibrated their valuations to this environment.

Then came the pandemic, hybrid work, and structural job market shifts. Office demand has not recovered to 2019 levels. More importantly, the nature of office demand has changed. Flex work, open office floor plans with more hoteling, and the permanent shift of some workforces to distributed models have reduced demand for traditional office space. Major markets like Austin and Dallas still grew, but the growth masked deteriorating fundamentals in secondary markets and mature office parks.

Today, in 2026, Texas office market conditions are materially different:

Downtown and Class A towers: Still strong in Dallas (downtown occupancy ~85%), Houston (downtown occupancy ~80%), and Austin (occupancy ~78%). But even Class A markets are seeing rent compression from oversupply in secondary markets. New construction completed in 2023–2025 is still being absorbed.

Mid-rise office parks (Class B/B-): This segment has been hit hardest. Occupancy rates in mid-rise suburban office parks now average 75% to 82% in major markets, down from 85%+ in 2019. Rents have stagnated or declined. Tenant move-outs have exceeded move-ins in many locations.

Older suburban office: Properties built pre-2000 and located away from primary business districts have seen the steepest value declines. Occupancy can drop to 65% to 75%. Rental rates for older space are now 15% to 25% below comparable newer product.

Secondary Texas markets: Places like Lubbock, Amarillo, Corpus Christi, Brownsville, and Beaumont have seen even greater office stress. Vacancy rates exceed 15% to 20% in many of these markets. Rental rates have declined in nominal terms for the first time since 2012.

Yet appraisal districts across Texas are still valuing office properties using 2019 or early-2020 assumptions about occupancy, rental rates, and capitalization rates. This creates systematic overassessment.

How Texas Appraisal Districts Value Multi-Tenant Office Buildings

To understand where appraisal districts go wrong, you must understand the income approach formula they use.

For multi-tenant office buildings, Texas appraisal districts estimate value using this framework:

Step 1: Calculate Potential Rental Income

The appraiser estimates what the building could generate if fully rented at market rates.

Potential Gross Revenue = Building square footage × Market rent per square foot

For example, a 100,000 square foot office building in a secondary Dallas market might be valued assuming $18 per square foot annual rent (a market rent assumption). That implies potential gross revenue of $1.8 million.

Step 2: Apply Vacancy and Rent Loss

The appraiser subtracts vacancy and assumes some percentage of rents will not be collected.

Effective Gross Income = Potential Gross Revenue × (1 − Vacancy rate)

Using a 10% vacancy rate: $1.8M × 0.90 = $1.62 million

Step 3: Subtract Operating Expenses

The appraiser estimates operating expenses as a percentage of gross revenue (typical range: 30% to 45% depending on building age and condition).

Net Operating Income (NOI) = Effective Gross Income − Operating Expenses

Assuming 38% operating expense ratio: $1.62M × 0.62 = $1.0044 million NOI

Step 4: Apply Capitalization Rate

The appraiser selects a capitalization rate (the percentage return investors require for that property type and risk profile).

Value = NOI ÷ Cap Rate

Using a 6.5% cap rate: $1.0044M ÷ 0.065 = $15.45 million value

Each of these steps contains assumptions. When assumptions are wrong, values are wrong.

The Specific Overassessment Patterns Hitting Texas Office

In 2026, Texas appraisal districts are making specific, recurring mistakes in office property valuation. These mistakes consistently inflate values above market reality.

Pattern #1: Market Rent Assumptions Don’t Reflect Actual Building Rents

This is the single largest source of office overassessment in Texas.

Appraisal districts use “market rent” surveys to estimate what a building should fetch in rental income. The problem: market rent surveys don’t account for the actual rents your specific building is getting.

A market rent survey might show that comparable office buildings in your Dallas suburb are leasing at $16 to $18 per square foot annually. The appraiser applies $17 per square foot to your building. But your building has several problems the comparables don’t have:

• Older HVAC systems that tenants complain about
• Outdated electrical systems that can’t support modern IT loads
• No recent capital improvement program
• Parking layout that doesn’t match modern standards

As a result, your building actually leases at $14 to $15 per square foot — a 10% to 15% discount to market rent. Yet the appraisal district has valued you at market rent, creating a 10% to 15% overassessment right out of the gate.

This problem is most acute in:

• Secondary suburban markets (Amarillo, Lubbock, Corpus Christi, Beaumont)
• Older office parks built 1990–2000
• Class B and Class C buildings competing with newer product
• Buildings in trade areas experiencing economic decline

Pattern #2: Vacancy Rates Lag Market Reality

Appraisal districts use historical or surveyed vacancy rates. In 2026, these lag actual market conditions by 12 to 24 months.

An appraisal district might use a 10% market vacancy rate for a secondary market when the actual current vacancy is 15% to 18%. The difference is dramatic:

100,000 sq ft office building, $17/sq ft market rent, 38% operating expenses:

• At 10% vacancy: NOI = $1.8M × 0.90 × 0.62 = $1.0044M
• At 15% vacancy: NOI = $1.8M × 0.85 × 0.62 = $0.9486M
• Difference in NOI = $55,800
• At 6.5% cap rate, difference in value = $860,000

A 5-point difference in vacancy assumption creates an $860,000 overassessment on a $15 million office building. And in many secondary Texas markets, that 5-point gap is real.

Pattern #3: Operating Expense Ratios Don’t Account for Building Condition

Appraisal districts often use average operating expense ratios (typically 35% to 40%) for buildings in a given class and location. But actual operating expenses vary substantially based on:

• Building age and condition
• HVAC systems (older systems cost more to operate and maintain)
• Parking lot condition (older lots require seal coating, repair, resurfacing)
• Tenant base (properties with high turnover have higher leasing commissions)
• Capital requirements (a building that will need a major HVAC replacement within 5 years)

An older office park might realistically have 42% to 44% operating expenses while the district assumes 38%. A newer, Class A building might operate at 32% to 35%. The district’s average assumption doesn’t match your building’s reality.

If your building’s actual operating expense ratio is 42% but the district assumes 38%:

• Overstated NOI = $1.62M × 0.04 = $64,800
• Overstated value (at 6.5% cap) = ~$1 million

Pattern #4: Capitalization Rates Ignore Building-Specific Risk

The cap rate is supposed to reflect the return investors require for that property. Properties with strong tenants, long leases, and stable cash flow justify lower cap rates (5.5% to 6.5%). Properties with weaker tenants, short leases, and volatile cash flow justify higher cap rates (7.0% to 8.5%).

Yet appraisal districts often use market-average cap rates that fail to account for your specific building’s risk profile:

• Your building has significant anchor tenant exposure (if the anchor leaves, you lose 25%+ of rents)
• Your building has above-average turnover
• Your building has below-average credit quality in the tenant base
• Your building is in a location experiencing long-term economic decline
• Your building will require major capital expenditures within 3–5 years

Using a 6.5% cap rate instead of a 7.5% cap rate looks like a small adjustment. It’s not:

Value at 6.5% cap on $1M NOI = $15.38 million Value at 7.5% cap on $1M NOI = $13.33 million Difference = $2.05 million (13.4% overassessment)

Pattern #5: Stabilization Assumptions Exceed Current Market

Some appraisal districts value office buildings assuming they will stabilize at occupancy levels that are not achievable in current markets.

An office building in a secondary Texas market with current occupancy of 72% might be valued assuming stabilized occupancy of 87%. But if the market vacancy rate is now 16%, stabilized occupancy for an older building cannot realistically exceed 82% to 84%.

By assuming 87% stabilization when realistic stabilization is 82%, the district overvalues NOI and therefore property value. For a 100,000 square foot building:

• 87% occupancy at $16/sq ft: Gross income = $1.392M
• 82% occupancy at $16/sq ft: Gross income = $1.312M
• Difference = $80,000 gross revenue
• At 38% opex ratio, NOI difference = $49,600
• At 6.5% cap, value difference = ~$763,000

Pattern #6: Functional and Economic Obsolescence Under-Valued

Appraisal districts are supposed to account for functional obsolescence (the building no longer works as originally designed) and economic obsolescence (the building’s location or trade area has deteriorated). Yet they frequently under-estimate or ignore these adjustments.

Examples of functional obsolescence in office buildings:

• Older buildings with elevator banks that don’t match modern space efficiency
• Buildings with column-heavy floor plates that can’t accommodate modern open floor plans
• Buildings with parking lots that were designed for a different ratio of cars to occupants
• Buildings with outdated electrical systems that can’t handle current technology loads

Examples of economic obsolescence:

• Office buildings in downtown areas experiencing population loss or business district decline
• Buildings in secondary market locations where the primary employer has relocated or shrunk
• Buildings in locations that have seen competitive oversupply from new construction

A building may have $12 million of replacement cost but only $8 million of actual market value due to functional and economic obsolescence. Yet appraisal districts sometimes value the building closer to replacement cost, ignoring these adjustments.

Evidence That Wins Multi-Tenant Office Protests in Texas

Building a successful multi-tenant office tax protest requires specific evidence that directly contradicts the district’s valuation assumptions.

#1: Current Rent Roll — The Most Powerful Evidence

Your actual rent roll shows what the building is really leasing for, with whom, and on what terms. This directly contradicts the district’s market rent assumptions.

Compile a complete rent roll showing:

• Tenant name and company type
• Suite number and square footage
• Current rent per square foot (total annual rent ÷ square footage)
• Lease expiration date
• Any tenant improvements or concessions provided
• Lease-up date (when did this tenant move in)
• Tenant credit quality (investment grade vs. below-investment-grade)

If your rent roll shows an average rent of $14.50/sq ft while the district assumed $17/sq ft, that’s a 14.7% rent discount that directly impacts value. This evidence is difficult for districts to refute because it’s based on actual executed leases, not surveys.

#2: Actual Occupancy Data

Provide year-over-year occupancy data for your building:

• Current month occupancy
• Occupancy 12 months ago
• Occupancy trend over past 3 years
• Lease-up rate (what percentage of vacant space is re-leasing per month)

If the district assumed 10% vacancy but your building runs at 15% to 18%, that directly impacts NOI. Real data from your own building cannot be dismissed as survey bias or market estimation error.

#3: Comparable Buildings with Published Sales Data

Identify sales of truly comparable office buildings that have closed in your market. You need buildings that are:

• Similar square footage
• Similar age and condition
• Similar lease-up status (not fully occupied at time of sale)
• Similar location and trade area

Most importantly, you need sales that reflect current market conditions, not pre-2024 sales. A 2023 office building sale that closed at $85/sq ft is much more relevant than a 2019 sale at $110/sq ft.

Sales provide a direct reality check on the district’s income approach value. If comparable buildings are selling at $10 million and the district valued your identical building at $14 million, that discrepancy demands explanation.

#4: Market Studies Showing Overvaluation in Your Asset Class

Third-party market research from CBRE, JLL, Colliers, or regional brokers showing:

• Current market vacancy rates (often higher than district assumptions)
• Current market rents (often lower than district assumptions)
• Cap rate trends for office buildings (often higher/more defensive than district assumptions)
• Market outlook for your specific submarket

If your district is using a 6.5% cap rate but market data shows cap rates of 7.0% to 7.5%, that’s direct evidence the district is being too aggressive.

#5: Tenant Lease Agreements

Provide redacted versions of major tenant leases showing:

• Actual rent rates
• Lease term length
• Tenant improvement allowances (especially if concessions were required)
• Rent escalation terms
• Options and renewal conditions

Redact only the confidential tenant information; show the economic terms. If a major tenant leased space at $15/sq ft with a $10/sq ft tenant improvement allowance, that shows the market rents your district is assuming are inflated.

#6: Capital Expenditure Requirements and Deferred Maintenance

Document required capital expenditures that will reduce property value:

• HVAC system replacement estimate (with engineering report)
• Roof replacement schedule
• Parking lot reseal or resurfacing
• Electrical system upgrades
• Structural repairs or code compliance items

A professional appraisal should deduct from gross income reserves for these items. If you have $500,000 of required capital work and the district didn’t account for it, that’s $500,000 of overstated NOI.

#7: Tenant Turnover and Leasing Costs

If your building experiences above-average tenant turnover, document it:

• Lease expiration schedule
• Turnover rate (percent of space that turns annually)
• Average lease-up period (time from lease-end to new tenant occupying space)
• Leasing commissions paid
• Tenant improvement costs per lease

High turnover properties should have higher operating expense ratios or lower NOI to account for permanent vacancy during turnover and constant leasing expense.

The Multi-Tenant Office Tax Protest Process in Texas

Texas Property Code § 41.41 governs the informal appraisal review process. For office buildings, the process works like this:

Step 1: Initiate Informal Review (within 30 days of notice of appraised value)

File a notice of protest with your appraisal district’s appraisal review board (ARB). This is always free and is your first line of dispute resolution.

Step 2: Informal Conference

Meet with an ARB representative to present your evidence. This meeting is often held by phone. Bring:

• Your rent roll
• Comparable sales data
• Market studies
• Physical photos of any condition issues

Many office property protests are resolved at this stage if you present clear evidence of overvaluation.

Step 3: Formal ARB Hearing (if informal conference doesn’t resolve)

If the informal process doesn’t result in value reduction, you can request a formal ARB hearing. You present evidence before a three-member ARB panel. The district can call its appraiser. You can cross-examine.

Step 4: District Court Appeal (if ARB decision is unfavorable)

If the ARB doesn’t agree with you, you can appeal to state district court. This requires engaging a lawyer and is expensive, but for multi-million-dollar overassessments, it can be worthwhile.

Why Multi-Tenant Office Protests Are Winnable

Multi-tenant office protests are among the most winnable categories of commercial property tax disputes because the evidence is clear and documented:

1. Rent roll is objective. It’s not a survey; it’s your actual leases. The district cannot dispute what you’re actually charging and getting for rent.

2. Market data is abundant. CBRE, JLL, Colliers, Zillow, CoStar, and other platforms publish market data constantly. An appraisal district using 2024 assumptions when 2026 market data says something different will struggle to defend their position.

3. Occupancy is measurable. You can show exactly how many square feet are occupied vs. vacant. The district’s assumption is just an estimate.

4. Sales comparables exist. Unlike some property types, office buildings sell regularly. Recent comparable sales provide a reality check on the income approach.

5. Cap rates are observable. If you can show that comparable office buildings in your market are trading at 7.5% to 8.0% cap rates, the district’s use of 6.5% is difficult to defend.

The key is to build your case methodically, using evidence your district cannot dismiss as biased or anecdotal. A rent roll, occupancy schedule, and recent comparable sales create a powerful foundation for any office property protest.

Related Resources and County-Specific Information

For specific guidance on your county’s appraisal district and tax protest procedures, review these resources:

• Dallas County: How to Protest Commercial Property Tax in Dallas County
• Harris County: How to Protest Commercial Property Tax in Harris County
• Tarrant County: How to Protest Commercial Property Tax in Tarrant County
• Travis County: How to Protest Commercial Property Tax in Travis County
• Bexar County: How to Protest Commercial Property Tax in Bexar County

For a comprehensive walkthrough of the entire Texas commercial property tax protest process, including timelines, evidence strategy, and what appraisal districts typically do to defend inflated valuations, see Complete Texas Commercial Property Tax Protest Process.

The 2026 office market has fundamentally changed from 2019. Appraisal districts that haven’t fully adjusted their assumptions are systematically overvaluing office buildings across Texas. If you own multi-tenant office space, the time to challenge your assessment is now. With clear evidence and a methodical approach, office property tax protests win regularly — often resulting in value reductions of 10% to 25% and tax savings that extend year after year.

Your appraisal district is counting on you to accept their valuation without challenge. Don’t. Build your case, file your protest, and recover the tax savings your building’s actual market conditions justify.