5-year and 7-year personal property
The highest-value reclassifications move building components to 5-year or 7-year property, where they can be paired with bonus depreciation for a large first-year deduction. Examples of 5-year personal property: specialty or decorative light fixtures (distinct from the building's base electrical), removable flooring installed over a subfloor (carpet and luxury vinyl plank tile), casework (non-structural built-in cabinets), outlet receptacles installed specifically for equipment, security and surveillance systems, and window treatments. Examples of 7-year personal property: freestanding office furniture, certain food-service equipment, and specialized fixtures in restaurants or retail.
The key question for any component is whether it is a structural component of the building or something that could be removed without damaging the building. Items serving a general building function (load-bearing walls, central HVAC, general plumbing) stay at 27.5 or 39 years.
15-year land improvements
15-year property includes all improvements to land that are separate from the building structure. Common items: parking lots and paved driveways, sidewalks, curbing and gutters, landscaping (including grading for drainage), exterior freestanding lighting, fencing, swimming pools, decorative water features, retaining walls, site utilities placed outside the building footprint, and outdoor signage bases. These components use the 150% declining balance method and are eligible for bonus depreciation.
In a typical suburban office building or retail center, 15-year land improvements alone may represent 8–15% of total project cost — and they depreciate at roughly twice the speed of 39-year property.
What stays at 27.5 or 39 years
Structural and mechanical components that serve the building as a whole remain at the building's standard recovery period: load-bearing exterior and interior walls, concrete slab or structural floor, roof structure and decking, central HVAC system (air handling units, ductwork, chillers serving the whole building), elevators and escalators, fire suppression (sprinklers), plumbing mains and risers, and the general building electrical distribution system. These are the non-negotiable long-life assets that cost segregation cannot touch.
Frequently asked questions
What is the most commonly reclassified item in a residential cost seg study?
Land improvements (parking, fencing, landscaping, exterior lighting) are the most reliably reclassified, since the 15-year vs. 27.5-year distinction is straightforward. Interior finishes like carpet are also common.
Can HVAC be reclassified in a cost seg?
Only if the HVAC unit serves a specific piece of equipment or a discrete area exclusively — not the building as a whole. A dedicated server-room cooling unit may qualify; a central building HVAC system does not.
Is a cost segregation study required to claim these categories?
No, you can self-classify obvious items like parking lots without a study. For complex or large properties, an engineered study provides the documentation needed to defend the allocations if audited.
Sources
Educational information and estimates only. Not tax advice. Tax rules change and vary by situation; consult a qualified tax professional before acting.