When you build a property from the ground up—whether it’s a commercial facility, multifamily complex, or custom residential investment—your construction costs can easily reach seven figures. But what many developers and investors overlook is that how you allocate those costs can dramatically affect your tax savings.
That’s where cost segregation comes in.
A cost segregation study allows you to accelerate depreciation deductions by breaking down your building’s components into categories with shorter recovery periods. This strategy turns long-term depreciation into immediate tax savings, improving cash flow and boosting return on investment.
In this guide, we’ll break down how cost segregation applies specifically to ground-up construction projects, including what qualifies, how the process works, and how to maximize the benefits while staying compliant with IRS rules.
What Is Cost Segregation?
Cost segregation is a tax strategy that separates a property’s components into different asset classes for depreciation purposes.
Ordinarily, the IRS requires that buildings be depreciated over:
- 27.5 years for residential rental property
- 39 years for commercial property
But not every part of a building lasts that long. Certain elements—such as flooring, wiring for specialized equipment, lighting, and landscaping—wear out much faster.
A cost segregation study identifies and reclassifies those assets into shorter depreciation lives (5, 7, or 15 years), allowing investors to accelerate deductions in the early years of ownership.
How Cost Segregation Applies to Ground-Up Construction
Most people associate cost segregation with existing buildings, but it’s just as valuable—if not more so—for new construction projects.
When you build from the ground up, every cost is tracked, documented, and classified, making it easier to pinpoint which expenses qualify for faster depreciation.
A ground-up project offers the cleanest opportunity for a precise and defensible cost segregation study because all the data is current, detailed, and verifiable through construction invoices, architectural drawings, and engineering specifications.
The Key Difference: Basis Creation vs. Allocation
When you buy an existing building, a cost segregation study allocates the purchase price among asset categories.
But in new construction, you’re not allocating—you’re creating the basis from scratch.
That means you can control how costs are categorized from the beginning, resulting in:
- Greater accuracy
- Higher percentage of assets reclassified to shorter lives
- More front-loaded depreciation deductions
Essentially, you’re designing your tax advantage as you build.
Components That Qualify for Accelerated Depreciation
In ground-up construction, roughly 20% to 40% of total building costs can typically be reclassified into shorter asset lives, depending on property type.
Here’s a breakdown of what usually qualifies:
5-Year Property (Personal Property)
- Carpeting, vinyl, and decorative flooring
- Cabinets, countertops, and millwork
- Lighting fixtures
- Dedicated electrical and plumbing systems (e.g., for appliances or equipment)
- Window treatments, signage, and partitions
- Specialty HVAC for equipment rooms or kitchens
7-Year Property
- Office furniture
- Fixtures and specialty shelving
- Equipment or machinery for business operations
15-Year Property (Land Improvements)
- Parking lots and driveways
- Sidewalks, curbs, and fencing
- Landscaping and irrigation systems
- Retaining walls and outdoor lighting
27.5- or 39-Year Property (Structural Components)
- Foundations, walls, roofs
- Main electrical and plumbing systems
- Elevators and structural steel
By categorizing each asset correctly during construction, you can claim accelerated depreciation on non-structural components right away.
Example: Ground-Up Cost Segregation in Action
Let’s say you complete a $5 million multifamily construction project.
Without cost segregation, the entire amount would be depreciated over 27.5 years, generating approximately $181,000 per year in deductions.
But with a professional cost segregation study, you might find:
- 25% qualifies as 5- or 7-year property
- 15% qualifies as 15-year property
- 60% remains as 27.5-year structural components
That means you could accelerate nearly $2 million in depreciation deductions within the first few years.
Using bonus depreciation (if available), you could potentially deduct up to the full reclassified amount in year one under 100% bonus depreciation, dramatically reducing taxable income.
Integrating Cost Segregation Into the Construction Process
To maximize the benefits of cost segregation in ground-up projects, planning should begin during the design and construction phase, not after completion.
Here’s how to integrate it effectively:
1. Pre-Construction Planning
Engage your CPA and cost segregation specialist early. They’ll coordinate with your architect, general contractor, and engineers to ensure costs are tracked by component.
2. Detailed Cost Tracking
Each line item—from flooring materials to lighting systems—should be itemized separately.
This level of detail makes post-construction classification much easier and more defensible.
3. Engineering-Based Study
After completion, an engineer conducts an analysis using:
- Construction drawings
- Material takeoffs
- Cost data and invoices
- Site inspections and photos
The result: a comprehensive report supporting your depreciation reclassifications in accordance with IRS Audit Technique Guidelines.
Bonus Depreciation and Section 179 Expensing (2025 Updates)
Ground-up construction projects can also leverage bonus depreciation and Section 179 expensing for qualifying assets.
Bonus Depreciation
Allows immediate expensing of qualifying 5-, 7-, and 15-year property.
The One Big Beautiful Bill Act restored bonus depreciation to a permanent 100% for qualifying property acquired and placed in service after January 19, 2025. The prior phase-down schedule has been repealed. For historical reference only, the superseded rates were:
- 60% in 2024 (superseded)
- 40% in 2025 (superseded)
- 20% in 2026 (superseded)
Applies to both new and used property as long as it’s the taxpayer’s first use and the property is “placed in service” in that tax year.
Note: The One Big Beautiful Bill Act, enacted in 2025, made 100% bonus depreciation permanent for qualifying property acquired and placed in service after January 19, 2025. Always confirm the latest rate with your CPA before filing.
Section 179 Deduction (2025 Limits)
For 2025, the Section 179 deduction limit is $2,500,000, with a phaseout beginning at $4,000,000 of qualifying property.
While primarily for small business property, certain non-structural improvements—such as HVAC, fire protection, or security systems in commercial buildings—can qualify.
This can further accelerate write-offs in the first year of use.
Combining cost segregation with bonus depreciation and Section 179 allows developers to recover a massive portion of their capital investment in year one, significantly improving project cash flow.
Bonus Depreciation vs. Section 179: How To Choose The Best Deduction Tool
When to Conduct the Study
The optimal time to perform a cost segregation study on a new construction project is immediately after the property is placed in service (i.e., when it’s ready for occupancy or income production).
Doing it within the same tax year lets you claim the maximum allowable deductions without filing amended returns later.
However, if you miss that window, you can still apply cost segregation retroactively by filing Form 3115 (Change in Accounting Method) to “catch up” missed depreciation.
Accelerated depreciation deductions are reported on IRS Form 4562 in the year the property is placed in service.
Documentation and IRS Compliance
Because cost segregation accelerates deductions, it’s a frequent area of IRS scrutiny. Proper documentation is key.
A defensible study should include:
- Detailed engineering and construction cost analysis
- Asset classification tables aligned with IRS Publication 946 (2025 edition)
- Photos, blueprints, and specifications
- Narrative explanation linking each cost to its classification
- Reconciliation to total project cost
Engaging a CPA who collaborates with certified cost segregation engineers ensures your study meets IRS standards and withstands audit review.
Common Mistakes to Avoid
Performing the Study Too Late
Waiting years after completion often means losing critical construction records or invoices, reducing accuracy and audit defensibility.
Using Rule-of-Thumb Estimates
Only engineering-based studies—not generic percentage allocations—are recognized by the IRS.
Ignoring Tenant Improvements
If you construct tenant build-outs, those costs often qualify separately for accelerated depreciation, but are frequently overlooked.
Combining Land and Building Costs
Land cannot be depreciated. Always separate it from building and site improvement costs to ensure compliance.
Neglecting Future Renovations
When you renovate or expand later, a follow-up study ensures new costs are properly reclassified without double-counting prior depreciation.
Who Benefits Most From Ground-Up Cost Segregation
Cost segregation can benefit nearly any developer or investor constructing new property, but it’s especially valuable for:
- Multifamily developers with large capital expenditures
- Commercial real estate investors (offices, retail, warehouses, medical facilities)
- Hospitality projects (hotels, resorts, restaurants)
- Industrial or manufacturing facilities with extensive electrical and mechanical systems
- Build-to-rent developers looking to offset early operating losses
Even smaller investors constructing duplexes or small apartment complexes can realize substantial benefits.
Financial and Tax Impact Example
Let’s illustrate how cost segregation affects cash flow.
Scenario:
Construction cost: $4,000,000
Tax bracket: 35%
25% of costs reclassified to shorter lives
Without cost segregation:
Depreciation (27.5 years): $145,000 per year
Annual tax savings: ~$50,750
With cost segregation and 100% bonus depreciation (acquired after January 19, 2025):
Immediate first-year deduction: $1,000,000
Tax savings: $350,000
That’s over a quarter-million dollars of upfront cash flow, which can be reinvested into new projects or used to reduce debt.
Long-Term ROI and Portfolio Strategy
The goal of cost segregation isn’t just tax deferral—it’s strategic cash management.
By accelerating depreciation early, you:
- Free up cash for expansion or reinvestment
- Improve your internal rate of return (IRR)
- Reduce your cost of capital
- Boost after-tax ROI in the early years when leverage is highest
Later, when the property is sold, the tax impact can be managed through:
- 1031 exchanges to defer gains
- Like-kind reinvestments
- Recapture planning with your CPA
When integrated into a long-term tax strategy, cost segregation becomes a cornerstone of sustainable real estate growth.
Cost segregation on a ground-up build
For ground-up construction projects, cost segregation reallocates building basis to shorter-lived components, which moves substantial depreciation into the early years.
By coordinating with your CPA, construction team, and cost segregation specialists from day one, you can:
- Identify and document qualifying components during construction
- Apply bonus depreciation and Section 179 strategically
- Reduce taxable income and boost cash flow in year one
- Maintain full IRS compliance through detailed, defensible studies
If you’re planning or recently completed a ground-up build, don’t leave depreciation to chance. The right cost segregation approach can transform your construction costs into an immediate financial advantage.
Schedule a call
Every construction project is different, and so is the schedule that comes out of it. A short call about the project, what a study would cover and whether it is worth commissioning: speak with a CPA about your situation.
