Cost Seg for New Construction vs Acquired Property
New construction cost segregation uses the detailed engineering approach from actual cost records (Pub 5653 Chapter 3 Method 1), the most defensible methodology because actual costs are documented in the construction records. Acquired property cost segregation uses engineering estimates derived from on-site inspection and comparable construction costs. Both produce defensible studies. New construction has slightly stronger audit posture.
New construction methodology
Construction projects produce detailed cost records: contractor invoices, subcontractor breakdowns, material purchase orders, change orders. The cost segregation engineer reviews these records and allocates each documented cost to the appropriate recovery period.
Pub 5653 Chapter 3 identifies the detailed engineering approach from actual cost records as the most accurate and most defensible methodology. New construction is the cleanest application of this method.
Acquired property methodology
For acquired properties, the engineer typically does not have detailed construction cost records. The methodology shifts to engineering estimation: site inspection, blueprint review where available, and comparable construction cost analysis to allocate the purchase price across components.
Pub 5653 Chapter 3 Method 2 (detailed engineering cost estimate) is the next most accurate methodology after Method 1. It is fully defensible when properly documented, just slightly less direct than working from actual cost records.
Bonus depreciation differences
New construction may include the building shell, which is real property and not eligible for bonus depreciation (only QIP and reclassified personal property and land improvements get bonus). The reclassified portion is bonus-eligible under OBBBA for post-Jan-19-2025 placed-in-service.
Acquired property has the same bonus depreciation rules for the reclassified components. The 5-year personal property and 15-year land improvements get 100% bonus under OBBBA.
Frequently asked questions
- How does WeCostSeg coordinate with my CPA?
- Every engagement follows the three-touch CPA Coordination Protocol. Preliminary analysis CC'd to your CPA on intake, draft report shared five business days before final delivery, and Form 3115 filing coordinated when a Section 481(a) adjustment applies.
- Does OBBBA's 100% bonus apply to my acquisition?
- 100% applies to property under a binding contract on or after January 20, 2025 per Public Law 119-21. Property under a binding contract on or before January 19, 2025 stays on the legacy phase-down: 40% in 2025, 20% in 2026, 0% in 2027 and after.
- Is audit defense included?
- Yes. Every WeCostSeg engagement includes five years of written audit defense at no extra charge, aligned to the 13 Principal Elements of a Quality Cost Segregation Study under IRS Publication 5653 Chapter 4.
- Can I get a free preliminary analysis?
- Yes. Submit property details via the free proposal form or WhatsApp. Engineer-reviewed estimate returned within four business hours during US Eastern hours.
Zawwad Ul Sami, Founder
Zawwad Ul Sami is the founder of WeCostSeg, a founder-led cost segregation firm serving real estate investors across the US. He focuses on strategy, pricing, and the firm's overall direction.