Here's an illustrative example. A private equity group completes a $25 million build-out of a Tier III colocation data center: dual 2,000-kW generators, N+1 cooling redundancy, a raised floor system spanning 25,000 square feet, and a security and monitoring network. On paper, these are capital expenditures to be depreciated over nearly four decades.

A detailed cost segregation study tells a different story. Say about 35% of the project’s depreciable basis, roughly $8.75 million, is reclassified into 5-, 7-, and 15-year property. If the full amount is deducted in year one with bonus depreciation, that is roughly $3 million in tax savings at a 35% rate, provided the loss can be used that year.

Which Data Center Components Can Qualify

Data centers contain components that can qualify for shorter depreciation schedules. Instead of waiting 39 years to recover those costs, owners can accelerate deductions across 5-, 7-, or 15-year property classes through cost segregation.

These can include:

• Power distribution and backup systems dedicated to IT equipment
• Precision cooling (CRAC/CRAH units) serving equipment loads
• Raised access flooring and dedicated cabling
• Site improvements like paving, drainage, and fencing

General building systems, such as building-wide security, fire suppression, and lighting, are generally part of the 39-year building. A cost segregation study separates the components that qualify from those that don't.

One distinction to get right first

Data centers hold two very different kinds of asset, and conflating them produces wildly inflated reclassification percentages.

The first is the building and its integral systems: shell, power distribution, cooling infrastructure, raised floor, structured cabling, security, and site work. This is what a cost segregation study reclassifies, and it behaves like any other industrial facility. Our benchmark for that work is 25% to 39% of depreciable basis, the same range we publish for industrial and warehouse property in our reclassification percentage benchmarks.

The second is owner-purchased IT equipment: servers, storage arrays, switches, and the rest of the compute stack. That equipment is depreciated on its own schedules, typically as 5-year property, and it is not part of the reclassification percentage at all. It sits outside the study basis the same way furniture bought separately for a rental property does.

Both generate deductions. But adding them together and calling the result a reclassification percentage produces a number that will not reconcile against a proposal, and will not survive scrutiny if anyone checks the arithmetic.

The Scale of Potential Tax Savings

Typically 25% to 39% of a data center’s depreciable basis reclassifies into shorter asset lives. The low end is the baseline result on a straightforward facility; the high end reflects heavy power and cooling infrastructure, extensive raised floor, and significant site work.

Consider a facility with a $50 million depreciable basis:

• $12.5–19.5 million of those costs may qualify as 5-, 7-, or 15-year property.
• With 100% bonus depreciation, the entire amount of those short-life assets can be deducted in the first year for property acquired and placed in service after January 19, 2025. For a new build, that generally depends on when construction began. Earlier property is subject to the phase-down: 40% for property placed in service in 2025 and 20% in 2026.
• At a 35% rate, that is roughly $4.4 to $6.8 million in first-year tax savings, if you can use the loss that year.

At a smaller scale, a $10 million regional data center reclassifying at the 32% midpoint moves about $3.2 million into short-life property. With 100% bonus depreciation, that is worth roughly $1.1 million in first-year tax at a 35% rate, if the loss is usable.

Those figures are for the building side alone. Servers and other IT equipment the owner buys are depreciated separately and add to the total deduction on top of this.

For investors and operators, earlier deductions can free up capital for new equipment, additional build-outs, or debt reduction. Instead of a 39-year straight-line schedule, owners can recover a significant portion of their investment in the early years.

The Process Behind a Defensible Study

A cost segregation study that can withstand IRS scrutiny is built on engineering, documentation, and tax compliance — not estimates or shortcuts. The most reliable studies follow a rigorous process:

1. Engineering analysis of the facility — Reviewing architectural drawings, mechanical and electrical plans, and construction invoices to identify each component of the build. For a data center, this means isolating systems like CRAC units, raised floors, power distribution, and generators from the structural shell.
   
   
2. Property inspection — Inspecting the property, with photos and satellite imagery, to confirm that the systems identified on paper match what is installed. This step is critical for specialized infrastructure where classification depends on actual use.
   
   
3. Detailed cost breakdown — Allocating project costs down to individual systems and materials, often by using contractor payment applications, vendor invoices, and change orders. The allocation must tie back to the total construction or acquisition cost with precision.
   
   
4. Asset classification — Assigning each item to the correct tax life (5, 7, 15, or 39 years) based on IRS guidelines. For example, a generator serving only IT equipment may qualify as 7-year property, while the building shell remains at 39 years.
   
   
5. Deliverable report — Producing a final study that includes methodology, calculations, photographic documentation, and legal references. This becomes the defensible record in the event of an IRS audit.

The difference between a defensible study and a risky one is often the depth of engineering involvement. A high-quality report doesn’t just provide numbers; it demonstrates exactly how those numbers were derived, so it can be supported if examined.

Avoiding Pitfalls and Managing Risk

The IRS reviews cost segregation studies closely, particularly on high-value facilities like data centers. Missteps don’t just reduce savings; they can lead to adjustments and penalties. The most common pitfalls include:

• Overly aggressive classifications — Treating structural components (e.g., load-bearing walls, roofs, or core HVAC systems) as short-life property. These misclassifications are the first targets in an IRS audit.
  
  
• Blending IT equipment into the building percentage — Counting separately purchased servers and racks toward the reclassification figure inflates the headline number without adding a dollar of deduction. Keep the two tracked separately.
  
  
• Insufficient documentation — Relying on percentage estimates or “rules of thumb” rather than hard construction records, invoices, and engineering analysis. Weak documentation undermines defensibility.
  
  
• Ignoring recapture exposure — When the property is sold, 5- and 7-year components are recaptured as ordinary income to the extent of gain, and building depreciation is taxed at up to 25%. A 1031 exchange can defer some or all of it, though §1245 recapture can still apply. Model the hold period before you sell.
  
  
• Lack of coordination with tax advisors — A study that isn’t integrated with a broader tax strategy may miss opportunities (like Section 179D energy deductions, for projects where construction began by June 30, 2026) or create unintended timing issues.

The way to mitigate these risks is to work with specialists who bring engineering, construction, and tax expertise together. A defensible study should be built to IRS standards, supported by a clear audit trail, and aligned with the owner’s overall tax strategy.

For data centers, where the distinction between specialized systems and the building shell can be subtle, choosing the right partner matters as much for accuracy as for the size of the deduction.

Next Steps

Data centers carry more specialized power and cooling infrastructure than most buildings, and some of it can be depreciated over shorter lives. Front-loading that depreciation through cost segregation can turn decades of slow write-offs into earlier, usable deductions.

If you own or are building a data center, R.E. Cost Seg can give you an estimate for your property before you commit to a study.