Land is never depreciable. Every dollar you assign to land is a dollar you will never deduct, for as long as you own the property. That makes land allocation the first number in a cost segregation study and, dollar for dollar, the most consequential one.
Owners get it wrong in both directions. Too much to land and you have quietly donated deductions. Too little and you have created the one kind of exposure in a study that genuinely invites scrutiny.
Key takeaways
- Land allocation happens before anything else. It sets the depreciable basis every other classification divides up.
- Four sources are commonly used, and they are not equally strong: the purchase agreement, an appraisal, the county assessor's ratio, and a site-value analysis.
- The assessor ratio is the most common method and the weakest, because assessed values serve a different purpose than tax basis.
- Land improvements are not land. Paving, utilities, landscaping, fencing, and site lighting are 15-year property, the most commonly missed item on self-prepared schedules.
- Two defensible methods can differ by six figures. Document the one you chose and why.
Why This Number Matters More Than Any Other
Consider a $2,500,000 property. Allocate 30% to land and you depreciate $1,750,000. Allocate 20% and you depreciate $2,000,000. That $250,000 is not deferred, not reclassified, not recovered later through a shorter life. It sits on the land line until disposition.
Then it compounds. A study typically reclassifies 20% to 30% of basis into 5-, 7-, and 15-year lives, so the $250,000 carries roughly $50,000 to $75,000 of additional short-life, bonus-eligible property with it. That is why the first question in any engagement, alongside the documents a study requires, is how land was determined.
The Four Allocation Sources, Ranked
| Source | Strength | When it governs | Weakness |
|---|---|---|---|
| Purchase agreement allocation | Strongest, if arm's length and real | Both parties negotiated and are bound by it | Rare; sometimes unsupported |
| Appraisal with segregated land value | Very strong | Available from financing or estate work | Many appraisals never isolate land |
| County assessor ratio | Moderate | Nothing better exists | Serves a tax levy, not basis |
| Site value or residual analysis | Strong, by a qualified professional | The assessor ratio is absurd | Requires comparable land sales |
The purchase agreement controls when it contains a genuine, negotiated allocation between unrelated parties. Opposing incentives are what give the number credibility; a figure neither side priced is worth much less.
An appraisal with a separately stated land value is the next best evidence, particularly one prepared for a lender at acquisition. Many appraisals, though, value the property as improved and never isolate land.
The assessor ratio is what most studies use: county land value divided by total assessed value, applied to your purchase price. Defensible, inexpensive, and weak, because assessed values exist to distribute a tax levy, go stale, and are often split by formula.
A site value analysis derives land value from comparable vacant land sales and treats the balance as improvements. That is the answer when the assessor ratio breaks down.
When the Assessor Ratio Produces an Absurd Result
Two situations recur.
High-land-value urban markets. In a dense downtown, the assessor may carry land at 55% of total value. Apply that to a $6,000,000 purchase and you strip $3,300,000 out of depreciable basis. Sometimes correct, because the land really is the asset; sometimes the assessment has not caught up with a renovation.
Rural and low-density land. The reverse. A $2,800,000 manufacturing building on 40 acres of farmland may show an assessor land value of 8%, or an agricultural use valuation unrelated to market value.
The tell is the same either way: run the ratio, then ask whether the implied building value could rebuild the structure. If it implies $60 per square foot for a medical office, the ratio is wrong.
Worked Example: A $180,000 Swing on the Same Building
Example: a $2.4M suburban medical office building Purchase price $2,400,000. The assessor carries land at $432,000 of a $1,920,000 assessed value, a 22.5% ratio. A lender appraisal concludes land value of $360,000, or 15% of the purchase price.
| Assessor ratio (22.5%) | Appraisal (15%) | |
|---|---|---|
| Purchase price | $2,400,000 | $2,400,000 |
| Land (nondepreciable) | $540,000 | $360,000 |
| Depreciable basis | $1,860,000 | $2,040,000 |
| Reclassified at 30% | $558,000 | $612,000 |
| Year-one bonus deduction | $558,000 | $612,000 |
| Tax value at 35% | $195,300 | $214,200 |
The two methods differ by $180,000 of depreciable basis, producing $54,000 more accelerated deduction in year one and roughly $18,900 of additional first-year deferral. Over the asset's life, the whole $180,000 is the difference between deductible and not. Both are defensible; the appraisal is the better evidence and the one we would document. Your result depends on your tax rate and whether you can use passive losses.
Land Improvements Are Not Land
The most commonly missed item on a self-prepared depreciation schedule, and worth stating flatly: the paving, utilities, landscaping, fence, and site lighting are not land. They are 15-year land improvements, depreciated on 150% declining balance and eligible for bonus depreciation:
- Paving, sidewalks, and curbs
- Site utilities outside the building footprint
- Landscaping immediately adjacent to and affected by the building
- Fencing, gates, and retaining walls
- Site lighting, including pole bases and underground feeds
- Drainage systems and monument signage
An owner who wrote "land $700,000, building $2,300,000" for a $3,000,000 retail property has usually buried $300,000 to $450,000 of 15-year property inside the 39-year building, and sometimes part of it in land, where it is never recovered. The 5-, 7-, and 15-year catalog walks the list, and correcting it is part of how a study works.
An Aggressive Land Number Is the One Thing That Invites Scrutiny
Most of a study is engineering judgment applied to physical assets, where reasonable professional disagreement is normal. Land allocation is different. It is a single, visible, high-dollar number, and an unsupported one is among the few things in a study that genuinely invites scrutiny.
Three practices reduce that risk. Never pick the method after seeing the answer: choose the best evidence first, then compute, because a file showing four methods run and the lowest adopted says exactly that. Do not let land drift below the site's own market value. And keep the evidence: closing statement, appraisal, assessor record, comparable land sales. An allocation with a documented basis is a position; one without is an assertion, the distinction audit risk and defense turns on.
A very high land ratio can also push a property below the point where a study pays, since engineering-based studies generally justify their cost above roughly $500,000 of depreciable basis and land comes out first. See minimum property value.
Frequently Asked Questions
Can I use the assessor's ratio if it clearly overstates land?
You can, but do not simply accept it. The assessor ratio is a convenience, not an authority. If it produces an implied building value that could not rebuild the structure, obtain an appraisal or site value analysis instead and document why the ratio was rejected.
Can I change my land allocation after the first year?
The allocation is part of your basis determination, not a depreciation method, so it is not corrected the way a misclassified asset is. Discuss the facts with your CPA. Changing a reported allocation requires support, and doing it purely to increase deductions is not a defensible reason.
Is a demolished building's cost added to land?
Costs of acquiring property in order to demolish an existing structure are generally capitalized to land rather than depreciated. Confirm the specific facts with your CPA before the study is scoped, because it can materially change depreciable basis.
See What Your Property Would Yield
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This article is provided by Precision Cost Segregation for general educational purposes and does not constitute tax, legal, or accounting advice. Tax outcomes depend on your specific facts, your tax rate, your passive activity position, and your entity structure. Figures shown are illustrative. Consult your CPA or tax advisor before acting, and engage a qualified professional to perform any cost segregation study. Information is current as of publication.
This article is general information, not tax or legal advice. Depreciation outcomes depend on your facts, elections, and current law — consult your CPA before acting. © 2026 Precision Cost Segregation.