To calculate land value for depreciation, divide the assessed land value shown on your property tax statement by the total assessed value, then multiply that ratio by the price you actually paid for the property. The result is the land portion of your cost, which you subtract from the total to find the building basis you can depreciate. Land itself is not depreciable, so getting this split right is what separates a defensible return from one that invites penalties.
The Property Tax Assessment Ratio Method
This is the method the IRS itself points to. Publication 527 says that if you are not certain of the fair market values of the land and the buildings, you can divide the cost between them based on their assessed values for real estate tax purposes.1Internal Revenue Service. Publication 527, Residential Rental Property – Separating Cost of Land and Buildings The county assessor has already done the hard part by assigning separate figures to land and improvements on your annual valuation notice.
The math has three steps:
- Divide the assessed building value by the total assessed value to get the building’s percentage.
- Divide the assessed land value by the total assessed value to get the land’s percentage.
- Multiply each percentage by what you actually paid for the property.
A worked example, drawn from the IRS’s own illustration: you buy a rental for $200,000. The most recent tax assessment values the whole property at $160,000, with $136,000 assigned to the house and $24,000 to the land. The building ratio is $136,000 ÷ $160,000, or 85%. The land ratio is $24,000 ÷ $160,000, or 15%. Apply those to your $200,000 purchase price and you have a depreciable building basis of $170,000 and a non-depreciable land value of $30,000.1Internal Revenue Service. Publication 527, Residential Rental Property – Separating Cost of Land and Buildings
The strength of this method is that the numbers come from a government entity rather than from your own estimate. The weakness is timing. If your county has not reassessed the property in years, the ratio may not reflect what land and structures are actually worth in your area now. In that situation the assessor’s figures still work as a starting point, but an appraisal gives you firmer ground.
When a Professional Appraisal Makes Sense
If the local assessment is stale, or the property is unusual enough that comparable tax data is thin, a licensed appraiser can establish the split. Ask specifically for the Cost Approach section of the report, where the appraiser calculates the replacement cost of the structure and assigns a separate value to the underlying site. Appraisers typically support the land figure by pointing to recent sales of vacant lots nearby.
If you are commissioning the appraisal for this purpose, ask for a clear itemized breakdown of land versus improvements and confirm the report follows the Uniform Standards of Professional Appraisal Practice. A compliant appraisal carries weight if the IRS ever questions your allocation, because it is an independent professional opinion backed by market data rather than a number you chose.
Full-scope appraisals for investment properties usually run several hundred to over a thousand dollars depending on the property and location. That cost is not itself depreciable, but it may be deductible as a business expense in the year you pay it. For a straightforward single-family rental, the tax-assessment ratio is normally enough. Appraisals earn their cost on higher-value commercial properties or when the assessor’s numbers look clearly out of step with reality.
Converting a Personal Residence to a Rental
If you are turning a former home into a rental, there is an extra step that catches many first-time landlords. Your depreciable basis is not simply what you paid years ago. It is the lesser of the property’s fair market value on the date you convert it to rental use, or your adjusted basis at that time.2Internal Revenue Service. Publication 527, Residential Rental Property – Basis of Property Changed to Rental Use
Adjusted basis is your original purchase price, plus the cost of any permanent improvements, minus any casualty loss deductions you previously claimed. If the property’s market value has dropped below that adjusted basis by the time you start renting, you must use the lower fair market value as the starting figure. You then apply the land-versus-building ratio to whichever number is lower. The rule exists to keep taxpayers from depreciating losses that occurred while the property was personal.
Watch the Line Between Land and Land Improvements
Raw land is never depreciable, but certain things done to the land are, and they should not be lumped into either the land figure or the building figure. Fences, paved driveways, parking lots, sidewalks, landscaping shrubbery, and bridges are 15-year property under MACRS and depreciate on their own schedule.3Internal Revenue Service. Publication 946, How To Depreciate Property – 15-Year Property
The distinction matters. General land preparation like clearing and grading gets added to the basis of the land and cannot be depreciated at all.4Internal Revenue Service. Publication 946, How To Depreciate Property But landscaping so closely tied to a depreciable structure that it would be destroyed if the building were replaced can be depreciated over the life of that structure. The gap between a 15-year deduction and no deduction at all is large, so if your property has meaningful site work, break those items out and track them separately rather than burying them in either the land or building line.
Two Details That Change the Total You Are Splitting
Before you apply any ratio, make sure you are dividing the right number. Certain settlement charges from your closing disclosure become part of the property’s cost basis and then get allocated between land and building using the same ratio: title insurance, transfer taxes, recording fees, legal fees, and survey costs are the common ones. Loan-related costs are different. Origination fees, discount points, mortgage insurance premiums, and lender-required appraisal fees do not become part of the basis at all.5Internal Revenue Service. Publication 551, Basis of Assets Sorting these before you calculate the ratio prevents an error that compounds across every year you own the property.
Also, only property held for business or income production is eligible for depreciation in the first place.6Internal Revenue Service. Topic No. 704, Depreciation A duplex where you live in one unit and rent the other still qualifies, but only the rental portion of the building enters the calculation. Your personal home does not, even if you go through the land-versus-building exercise.
Records to Keep and Penalties for Getting It Wrong
The IRS puts the burden of proving your depreciation deductions on you.7Internal Revenue Service. Burden of Proof You must keep records supporting the property’s basis until the statute of limitations expires for the tax year in which you sell or dispose of it. That is normally at least three years after filing the return for the year of sale, and six years if you underreport income by more than 25%.8Internal Revenue Service. Publication 583, Starting a Business and Keeping Records
In practice, if you hold a rental for 20 years and then sell it, you need the original closing disclosure, the tax assessment you used to build your ratio, and any appraisal reports for something on the order of 23 years after purchase. Losing these documents is one of the more common reasons landlords struggle in an audit.
The cost of getting the allocation wrong is real. If you inflate the building’s share to claim larger deductions and the IRS finds it, the accuracy-related penalty adds 20% on top of the underpaid tax. A gross valuation misstatement doubles that to 40%.9Office of the Law Revision Counsel. 26 U.S. Code 6662 – Imposition of Accuracy-Related Penalty on Underpayments The defense against both is documentation. A ratio drawn from the county assessor’s numbers, or a value drawn from a USPAP-compliant appraisal, is a supported allocation. A number chosen because it produced the largest deduction is not.