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Cost Segregation for Contractors Who Own Their Shop, Yard or Building
Cost Segregation for Contractors Who Own Their Shop, Yard or Building
The short answer: if your construction company owns its shop, yard, office or warehouse, a cost segregation study can move parts of that property out of the 39-year depreciation schedule and into 5-, 7- and 15-year lives, so the deductions arrive years earlier. It does not create new deductions. It changes when you get them. That makes it a cash flow decision, and for contractors who own real estate it is usually worth a serious look.
If the idea is new to you, start with Cost Segregation for Construction Contractors. This page is about the situation most contractors are actually in: you already own the property your business runs from.
What cost segregation does
When you buy or build a commercial property, the IRS treats the whole building as lasting 39 years (27.5 for residential rental property) and lets you depreciate it in equal slices over that time. But a building is not one thing. It is a structure plus electrical work, plumbing, finishes, equipment connections and site work, and many of those components have much shorter lives under the tax rules.
A cost segregation study is an engineering-based analysis that identifies those components and assigns each one its proper recovery period. Personal property inside the building can fall into the 5- or 7-year classes. Land improvements such as paving, fencing, lighting and drainage generally fall into the 15-year class. Whatever is left stays at 39 years, and the land itself is never depreciated.
Why contractor-owned property is a strong candidate
Contractors tend to own exactly the kind of property where a large share of the cost is not the building shell:
- Shops with heavy electrical service, compressed air and dedicated circuits for equipment
- Yards with paving, fencing, gates, lighting and drainage
- Specialized HVAC, ventilation and wash bays
- Custom office build-outs and finishes
Those are the components a study pulls forward. A plain office suite with little site work has less to reclassify. A working yard with a shop on it usually has more.
How bonus depreciation changes the math
Components reclassified into 5-, 7- and 15-year lives can qualify for bonus depreciation. Under the 2025 tax act, bonus depreciation is 100 percent and permanent for qualifying property acquired after January 19, 2025, so a study on a recently acquired property can move a meaningful part of its cost into the first year. The 39-year building itself does not qualify. Watch the dates: property covered by a binding contract signed before January 20, 2025 is treated as acquired when the contract was signed.
California does not follow the federal rules
California does not conform to federal bonus depreciation. A study still matters for your state return, but the first-year California deduction will be smaller than the federal one, and California needs its own depreciation schedule. Expect your federal and state numbers to differ, and plan cash around both.
Already own the building? You can still catch up
You do not have to have bought the property this year. If you have owned it for years and depreciated everything at 39 years, a study can identify what was missed, and the difference is generally claimed in the current year through an accounting method change on Form 3115, without amending earlier returns. We walk through how that works, and what the IRS expects a study to show, in How a Cost Segregation Study Works for Contractors.
Who owns the property matters
Many contractors hold their real estate in a separate LLC and lease it to the operating company. That is common and often sensible, and it means the study and the depreciation belong to the entity that owns the property, not to the construction company. Make sure the study is ordered by, and the deductions claimed on, the right return.
When it does not make sense
- You plan to sell soon. Faster depreciation on shorter-life components is generally recaptured as ordinary income when you sell. See depreciation recapture when you sell.
- The property is small. If the cost of the building, excluding land, is modest, the study fee can eat most of the benefit.
- You cannot use the deductions yet. If the company has little taxable income this year, the extra depreciation may mostly create a loss that waits for future years.
Frequently asked questions
Is cost segregation legal?
Yes. It is a recognised way of assigning each part of a property its correct depreciation life, and the IRS publishes a Cost Segregation Audit Techniques Guide that explains what it expects a study to contain. A study prepared by qualified specialists with a documented method is what holds up in an exam.
Can I do a cost segregation study on a building I bought years ago?
Yes. If the property has been depreciated entirely at 39 years, a study can identify what was missed, and the difference is generally claimed in the current year through an accounting method change on Form 3115, without amending prior returns.
Does cost segregation work if my building is owned by a separate LLC?
Yes. The study and the depreciation belong to whichever entity owns the property. If your real estate LLC leases the building to your construction company, the real estate LLC claims the deductions.
Does California follow the federal rules?
Not fully. California does not conform to federal bonus depreciation, so the first-year deduction on your California return will be smaller than the federal one, and the state needs its own depreciation schedule.
Find out whether your property qualifies
We look at what you own, when you bought it and how it has been depreciated, and tell you plainly whether a study is worth paying for.
Sources: IRS Publication 946 (recovery periods); IRS Cost Segregation Audit Techniques Guide; One Big Beautiful Bill Act, bonus depreciation; FTB Form 3885 instructions (California conformity). This is general information, not legal or financial advice.
Disclaimer: This content is provided for educational purposes only and is not legal, tax, accounting, or financial advice. Every situation is unique, so consult your own attorney, CPA, or financial advisor before making decisions based on this information.
