Site improvements: the 15-year story

Why site work is its own asset class

For tax purposes, an industrial property is not one asset. It is three. The raw land underneath is non-depreciable and stays on the books at its allocated cost forever. The building shell — the slab, the tilt-up or metal walls, the roof, the structural frame — is real property depreciated over 39 years. Everything in between, the engineered work that turns a bare parcel into a functioning logistics site, is a separate category: land improvements, depreciated over 15 years under the modified accelerated cost recovery system described in IRS Pub 946.

That 15-year designation is the entire reason a cost segregation study matters on a warehouse. A study does not change what you paid, and it does not invent deductions; it reclassifies portions of your existing cost basis from the slow 39-year bucket into the faster 15-year bucket where the engineering record supports it. The reclassification percentage is an engineering estimate, and any first-year depreciation figure that follows is a modeled tax estimate that depends on your §481(a) catch-up position, the bonus rate in effect for your placed-in-service date, state conformity, the §469 passive-activity rules, and your entity structure.

What makes warehouses distinctive is the share of total cost that lives outside the building. A distribution facility is a relatively plain box surrounded by an enormous amount of engineered site work — acres of it. The shell may look unremarkable, but the yard is where the capital concentrates, and the yard is overwhelmingly 15-year property. That is why a warehouse with a modest-looking structure can still reclassify meaningfully: the study follows the cost into the site improvements.

What counts as a 15-year land improvement

The category is broad, and on a logistics site it captures the bulk of the visible — and invisible — work surrounding the building. A study examines each of these elements against the plans and the site record:

• Truck courts and dock aprons — the heavy-load paving where trailers stage, maneuver, and back into the docks, engineered to a far greater thickness than ordinary parking.
• Parking lots and drive lanes — employee and visitor parking, internal circulation roads, and gate-access drives.
• Curbs, sidewalks, and aprons — concrete flatwork that is part of the site rather than the building.
• Storm drainage and detention — catch basins, piping, retention and detention ponds, bioswales, and the grading that moves water off acres of impervious surface.
• Fencing and gates — perimeter security fencing, manual and motorized gates, and bollards.
• Yard and site lighting — pole-mounted fixtures, their poles, bases, and the site-side conduit and wiring that serve them.
• Striping, signage bases, and pavement markings — the foundations and structural supports for site signage, along with striping.
• Landscaping and irrigation — planting, berms, and the irrigation system supporting them.

A point that surprises many owners: the storm drainage system counts even though almost none of it is visible. The piping, the structures, and the detention basin are buried below grade, but they are engineered land improvements with documented cost, and on a large impervious site that cost is substantial. An engineering-based study quantifies below-grade work from the civil and grading drawings rather than from what can be seen on a walkthrough — which is precisely why the methodology matters.

Truck courts: usually the single biggest move

Of all the site improvements, the truck court is the one that most often dominates the study. Two things drive that. The first is engineering: a truck court has to carry the wheel loads of fully laden tractor-trailers turning, braking, and parking under a dock door, day after day. That demands a pavement section dramatically heavier than a passenger-car parking lot — deeper aggregate base, thicker concrete or asphalt, and in many designs reinforced concrete dollypads at the dock face where the trailer landing gear concentrates load. More material per square foot means more cost per square foot.

The second is area. On a big-footprint distribution building, the truck court wraps the dock side of the structure and runs the full length of the loading face, often spanning the depth needed for a 53-foot trailer to swing in. Heavy unit cost multiplied across a large area produces a line item that frequently exceeds any other single reclassified element — and all of it is 15-year land improvement, not 39-year building. On the largest warehouses we see, the truck court alone can be the difference between a routine result and a study that materially changes the depreciation schedule. The exact share is property-specific and is determined by the engineering takeoff, not assumed.

Documenting it in the study

Reclassifying site work is not a matter of opinion; it is a matter of measurement. An engineering-based study starts from the civil, grading, paving, and site-utility drawings and performs a quantity takeoff — measuring the square footage of each pavement type, the linear footage of fencing and drainage runs, the count of light poles, the volume of detention storage — and reconciles those quantities against site observation. Each element is then costed from the owner’s actual basis and assigned to its recovery period.

The recovery periods themselves follow the asset classes set out in IRS Pub 946 and the framework laid out in the IRS Cost Segregation Audit Techniques Guide (Pub 5653), which devotes specific attention to how land improvements are identified and distinguished from building components. The result is a documented allocation that traces every 15-year dollar back to a measured quantity and a published authority. To see how the categories come together on a representative property, walk through our example study, and review what reclassifies in a warehouse for the building-side detail. Because the value of accelerating those 15-year assets depends heavily on the bonus rate in effect when the property was placed in service, the guide on bonus depreciation by PIS year is the natural next read.

Every reclassification percentage is an engineering estimate, and any depreciation figure shown anywhere in our materials is a modeled tax estimate — it varies with §481(a), the applicable bonus rate, state conformity, §469, and your entity structure, and your tax advisor applies the result to your return. To model your own property against these categories, start an estimate at costsegsmart.com/order.

See how cost segregation works and the engineering methodology at Cost Seg Smart.