🇺🇸 Made in America·100% U.S.-Based Team · 24+ Years in Cost Segregation
When you build a property, you generate exactly the records a cost segregation study most wants: actual documented costs for actual components, from contractor invoices, draw schedules, and change orders. A study on acquired property has to estimate what components cost within a lump-sum purchase price. A study on a self-constructed property can frequently tie classifications to real invoices. That makes ground-up development the strongest documentary position in cost segregation, and it makes throwing away those records one of the more expensive filing decisions a developer can make.
A developer in Sheboygan, Wisconsin finished a small industrial flex building and did what he had done on every project for twenty years. He closed out the job file, kept the lien waivers and the final contract, and got rid of the rest. The pay applications, the subcontractor invoices, the change orders, the detailed schedule of values. All of it, gone into a box marked for disposal.
His accountant caught it before the box left the office. Those records were the single most valuable tax documentation the project would ever produce, and he had nearly destroyed them three months after completion.
Most developers do not think of construction accounting as tax documentation. It is job cost tracking, it is for managing the build and paying subs, and once the building is done its purpose feels finished. That is a costly misunderstanding, and this article explains why.
Start with the difference between the two situations, because it is the whole point.
When you buy an existing building, you pay one number for the whole thing. That price does not come itemized. Nobody hands you a schedule showing what portion of your purchase price represents the electrical distribution, the site paving, or the interior finishes. A cost segregation study on an acquired property therefore has to work backward, using engineering analysis and cost estimation methods to determine what those components would have cost and allocating the purchase price accordingly. Done properly under the IRS-preferred methodology, that is rigorous, defensible work. It is also, by necessity, reconstruction.
When you build, none of that reconstruction is necessary. You paid the electrician a specific amount on a specific invoice. The site contractor billed the paving separately. The schedule of values broke the project into line items because that is how construction lending and payment applications work. The cost of each component is not estimated. It is documented, in an invoice, from an unrelated third party, contemporaneous with the work.
That is the best documentary position available in this entire field. The ATG framework contemplates using actual cost records where they exist, and a developer has them by default.
If you are a developer, here is what to preserve and why each item matters.
The schedule of values and pay applications. These break the contract into components and track billing against each. They are the backbone of a cost allocation, because they show what was paid for what, month by month.
Subcontractor invoices and contracts. Trade-level detail. The electrical contract, the mechanical contract, the site work contract, the finish trades. Each one documents the cost of a distinct scope of work.
Change orders. Frequently overlooked and frequently significant. Change orders document additions and modifications with their own costs, and on a project with substantial changes they can represent a meaningful share of total cost.
The general contractor's final cost breakdown. A closeout document that summarizes the project by category.
Architectural and engineering plans and specifications. These describe what was actually built, which supports how components are analyzed and classified.
Soft cost detail. Architect fees, engineering fees, permits, and similar indirect costs. These are generally capitalized into the project and allocated across the improvements, so knowing what they were and how they relate to the work matters.
Draw requests and lender inspections. Third-party contemporaneous verification that specific work was completed at specific points.
Together, those documents let a study tie classifications to real numbers rather than estimates. That is a materially stronger position if anyone ever asks questions.
Developers should understand the general shape of what gets capitalized, because it affects the size of the basis a study works with.
Direct construction costs are capitalized into the property. So are many indirect costs allocable to the production of the property, under the uniform capitalization rules. Certain interest incurred during the production period is also generally subject to capitalization rules rather than being currently deductible.
The practical effect is that a developer's depreciable basis is typically larger than the hard construction contract alone. Soft costs and capitalized carrying costs ride along with it. Those capitalized amounts are generally allocated across the improvements, which means a portion follows the components into whatever recovery periods those components take.
The mechanics of what must be capitalized, how indirect costs are allocated, and how interest capitalization is computed are genuinely technical and belong with your CPA. The point for planning is simply that the basis subject to a cost segregation analysis on a development project is often larger than developers assume, and getting the capitalization right feeds directly into getting the study right.
This distinction deserves its own attention on development projects because it is where real money moves and where sloppy analysis shows up.
Land is never depreciable. Raw land cost stays out of the depreciable basis entirely. Certain costs associated with preparing land can be so closely tied to the land itself that they are treated as non-depreciable land cost rather than as depreciable improvements.
Other site work is generally analyzed as land improvements with a recovery period shorter than the building structure. On a development project with substantial site work, parking, drives, utilities, and exterior features, the allocation between non-depreciable land cost and depreciable land improvements can involve significant dollars.
Where any specific site cost falls is an engineering and tax determination on the facts of that project, not a matter of applying a generic list. This is precisely the kind of question that benefits from having the actual site contractor's invoices in hand, showing what was done and what it cost, rather than estimating it later.
For a developer, the placed-in-service date is not an afterthought. It determines the tax year the deductions land in and which bonus depreciation rate applies.
Property is generally placed in service when it is in a condition of readiness and availability for its assigned use. On a construction project, that generally means completion to the point the building can be used for its intended purpose. On a project finishing near year end, a few weeks in either direction can move a very large deduction between tax years.
The current stakes are high. The One Big Beautiful Bill Act, signed into law on July 4, 2025, permanently restored 100 percent bonus depreciation for qualifying property acquired and placed in service after January 19, 2025. Projects that straddle that cutoff need careful analysis, and IRS Notice 2026-11 preserved a component election that can allow certain components of a larger project to be treated separately for bonus depreciation timing. On a straddling project, that election can preserve bonus on portions that would otherwise fall on the wrong side of the date. Applying it correctly requires the component analysis to support it, which is another argument for having the study built off real construction records.
Phased projects add another layer. A multi-building development delivering in stages may have portions reaching readiness at different times. Planning that deliberately, rather than reconstructing it afterward, is worth real money.
There is a compounding advantage here that experienced developers understand and newer ones often miss.
If you build regularly, establishing the practice of preserving construction cost detail and commissioning an engineered study on each completed project turns cost segregation from an occasional project into a system. Each building produces documented components, accelerated deductions, and a defensible file. Across a pipeline, that materially changes after-tax returns and, for developers who reinvest, changes how much capital is available for the next project.
The developers who treat it as an afterthought pay for it twice. Once in deductions taken slowly that could have been taken quickly, and once in the reconstruction cost of building a study without the records that were sitting in a box three years earlier.
Keith Cunningham's framing applies cleanly. The Sheboygan developer was not going to lose money on a line item he could see. He was going to lose it on a box of paperwork he thought was worthless, which is exactly how expensive mistakes usually happen. Nobody makes them in the categories they are watching.
Discarding construction records after closeout. The single most costly habit. Those records are the strongest possible documentation for a study, and they are irreplaceable once gone.
Assuming the general contract total is enough. A lump-sum contract amount without the schedule of values or trade detail forfeits most of the documentary advantage of having built the property.
Overlooking change orders. They can represent a meaningful share of total project cost and they document their own scopes and prices.
Ignoring soft costs and capitalized carrying costs. These generally ride into basis and allocate across improvements, and leaving them out understates the basis a study works with.
Treating the placed-in-service date as whatever the calendar says. On a project finishing near year end, the date is a planning decision worth modeling.
Waiting until tax season to think about it. The best time to set up a development project for a clean study is while it is being built.
If you are building now, tell your accounting team and your general contractor that construction cost detail is being preserved for tax purposes. Keep the schedule of values, pay applications, subcontractor invoices, change orders, and closeout breakdown. Keep the plans and specifications. Keep the soft cost detail. It costs nothing to retain and it is worth a great deal.
If you completed a project recently and still have the file, that project is an excellent cost segregation candidate and the documentation is right there.
If you completed a project years ago and never did a study, a lookback through a change in accounting method can generally capture the acceleration you did not claim, applied on your current-year return without amending old returns. If you still have the construction file, the study will be stronger than most.
The Cost Seg America team performs engineered studies using IRS Approaches 1 and 2, working from actual construction cost records where they exist. More than 16,000 studies completed. More than 125 IRS audits defended with zero losses and zero dollars ever returned to the IRS. Engineered, not estimated.
Request a free proposal, or reach out to the Cost Seg America team directly:
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info@costsegamerica.com
Why is a self-constructed property a better cost segregation candidate?
Because you have actual documented costs for actual components from contractor invoices, pay applications, and change orders. A study on an acquired property has to allocate a lump-sum purchase price using engineering estimation. A developer can frequently tie classifications to real third-party invoices.
What construction records should I keep?
The schedule of values, pay applications, subcontractor invoices and contracts, change orders, the general contractor's final cost breakdown, plans and specifications, soft cost detail, and draw request documentation.
Do soft costs like architect fees affect the study?
Generally yes. Many indirect costs allocable to producing the property are capitalized into basis and allocated across the improvements, which means they follow components into their recovery periods. The specific capitalization mechanics are a CPA determination.
How does the placed-in-service date work on construction?
The property is generally placed in service when it is ready and available for its assigned use, which typically means completion to the point it can serve its intended purpose. On projects finishing near year end, timing can move deductions between tax years.
What if my project straddles the January 19, 2025 bonus cutoff?
IRS Notice 2026-11 preserved a component election that can allow certain components of a larger project to be treated separately for bonus depreciation timing. Applying it requires component analysis to support it, and the determination belongs with your CPA.
Can I still do a study on a project I completed years ago?
Yes. A change in accounting method can generally capture previously unclaimed acceleration on your current-year return without amending prior returns. If you retained the construction file, the study will be unusually well documented.
Is land preparation depreciable?
It depends on the specific cost. Some costs tied closely to the land itself are treated as non-depreciable land cost, while other site work is generally analyzed as depreciable land improvements. The determination is made on the facts by engineering and tax analysis.
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