For the first time in decades, the building itself can be written off

Depreciation planning for manufacturers has always run into the same wall: whatever a cost segregation study could carve out as 5-, 7-, or 15-year property, the building shell — usually the largest single number on the schedule — sat in 39-year straight-line. Bonus depreciation never touched it.

The One Big Beautiful Bill Act changed that. New Section 168(n) allows an elective 100% first-year deduction for “qualified production property” — the nonresidential real property itself — for facilities used in qualifying production activities. For a manufacturer planning a new plant, the difference between 39-year recovery and a full year-one write-off of the production space is the largest depreciation swing the code has offered on real property in living memory.

The catch — and the reason this is a documentation exercise as much as a tax election — is that the deduction applies only to the portions of the building actually used in production. Offices, administrative space, parking, sales areas, research space: excluded, square foot by square foot. Someone has to measure, cost, and defend that allocation. That is precisely what an engineering-based cost segregation study does.

What qualifies: the requirements in plain terms

Qualified production property is, generally, nonresidential real property meeting all of the following:

• Use. The property is used by the taxpayer as an integral part of a qualified production activity — the manufacturing, production, or refining of tangible personal property. The activity must result in a substantial transformation of the property comprising the product. (Agricultural and chemical production count; producing food or beverages at a retail site where they are sold does not.)
• Timing. Construction begins after January 19, 2025 and before January 1, 2029, and the property is placed in service in the United States before January 1, 2031.
• Original use / qualified acquisition. Original use generally must begin with the taxpayer. There is a meaningful exception for purchased existing buildings: acquired property can qualify if it was not used in a qualified production activity by anyone between January 1, 2021 and May 12, 2025, and the acquisition meets the same timing windows — a genuine opportunity for manufacturers buying and converting idle warehouse, distribution, or other non-production buildings.
• Election. Section 168(n) treatment is elective, made in the manner the IRS prescribes. It is not automatic.

Excluded by statute is any portion of the building used for offices, administrative services, lodging, parking, sales activities, research activities, or software development or engineering activities. The exclusions are functional and spatial — which is why the square-footage question decides the size of the deduction.

Two structural cautions before modeling anything:

• The user must be the taxpayer. The statute requires use by the taxpayer in its production activity. A landlord leasing a building to a manufacturer is generally not conducting the production activity itself. In common related-party structures — real estate LLC leasing to the operating manufacturer — who owns the building matters enormously here. Review the structure before construction begins, while it can still be fixed.
• Ten-year recapture. If the property ceases to be used in a qualified production activity within ten years of being placed in service, the benefit is recaptured as ordinary income. The election deserves a durability conversation, not just a rate calculation.

Where cost segregation fits: certifying the square footage

A Section 168(n) election without an allocation methodology behind it is an audit invitation. An engineering-based cost segregation study supplies the substantiation in three layers:

1. Functional space allocation. The study maps the facility use by use — production floor, process support, warehousing integral to production, versus office, administrative, sales, R&D, and parking areas — and ties measured square footage to construction cost, area by area. That produces the defensible split between QPP-eligible building cost and excluded 39-year cost.
2. Traditional reclassification of everything else. The same study identifies the 5-, 7-, and 15-year property in the project — process electrical and plumbing, specialty systems, land improvements — which is separately eligible for the now-permanent 100% bonus depreciation under Section 168(k). QPP and bonus work side by side, on different asset classes.
3. A recapture-ready record. Because the ten-year recapture rule turns on continued qualified use of identified space, the study’s documented baseline — drawings, square footage schedules, cost detail — is what a future reviewer measures change against.

What the numbers look like

Assume a manufacturer breaks ground in 2026 on a $20,000,000 facility — 120,000 square feet — placed in service in 2028. The study allocates:

Component	Cost	Treatment	Year-one deduction
5-year process-support property	$2,600,000	100% bonus (§168(k))	$2,600,000
15-year land improvements	$1,400,000	100% bonus (§168(k))	$1,400,000
Building — production space (96,000 sq ft, 80%)	$12,800,000	§168(n) election	$12,800,000
Building — office / admin / R&D space (24,000 sq ft, 20%)	$3,200,000	39-year straight-line	≈ $82,000
Total	$20,000,000		≈ $16,882,000

Roughly 84% of the total project cost is deducted in the placed-in-service year, versus about $1.3 million of first-year depreciation if the entire project simply ran through a 39-year schedule with a conventional cost segregation study alone capturing the short-life property. The swing is driven almost entirely by the production-space square footage — which is why the measurement, not the election form, is where the value gets won or defended.

Planning points for CPAs

1. Watch the construction-start window. The begin-construction requirement (after January 19, 2025, before January 1, 2029) makes 2026–2028 groundbreakings the sweet spot. Document when physical work of a significant nature begins.
2. Get the ownership structure right first. If the building will sit in a related leasing entity, the taxpayer-use requirement needs analysis before the deal closes — not at return time.
3. Design with the exclusions in mind. Where office and administrative space is consolidated — a mezzanine, a distinct wing — the allocation is cleaner and the qualifying percentage typically higher than when excluded uses are scattered through the production envelope.
4. Screen acquisitions, not just new builds. The 2021–2025 non-production-use lookback for acquired buildings means an idle or repurposed facility purchased after January 19, 2025 can qualify. Ask the question on every manufacturing acquisition.
5. Model the recapture scenario. Ten years is a long time in manufacturing. Consolidations, product exits, and sale-leasebacks all touch the recapture rule.
6. Check state conformity. As with bonus depreciation, expect states to decouple unevenly. The federal deduction may need a state add-back schedule from day one.

The takeaway

Section 168(n) turns the largest, slowest asset on a manufacturer’s books into a year-one deduction — but only for the space that genuinely earns it, and only with the documentation to prove which space that is. The election is simple; the substantiation is not. An engineering-based cost segregation study, scoped from the design phase, does double duty: it certifies the qualifying production square footage for the Section 168(n) election and captures the conventional short-life reclassifications alongside it. For any client with a plant on the drawing board — or an idle building worth converting — this belongs in the conversation now, while the construction-start window is open.

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Corporate Tax Advisors performs engineering-based cost segregation studies for manufacturers, including functional square-footage allocations supporting Section 168(n) qualified production property elections. If you have a client planning, building, or acquiring production space, we are glad to model the numbers with you before decisions get locked in.

This article is general information, not tax advice, and does not create a client relationship. IRS guidance on Section 168(n), including election mechanics, continues to develop — apply it to your specific facts with your tax advisor.