A commercial property rarely stays the same across your lease duration. Roofs age, parking lots crack, and HVAC systems reach the end of a service life. The real question for a buyer is not whether a property needs improvement over time, but who pays for it and how the cost affects total return. In 2026, the answer rests a great deal on lease structure, and that single distinction explains why triple net (NNN) buyers approach commercial property improvement in a different way than owners of multi-tenant retail or office assets.
What Qualifies as a Commercial Property Improvement in 2026
The IRS draws a firm line between a repair and an improvement, and the line changes how a cost hits your return. A repair restores a property to its original condition, such as a patched roof leak, a fixed parking lot pothole, or a replaced light fixture. An improvement adds value, extends useful life, or adapts a property to a new use. Per IRS guidance on capital improvements, a replacement of major building components or substantial structural parts counts as a restoration and gets treated as a capital improvement rather than a repair. A full roof replacement, a new HVAC system, and an added wing all fall into the category of an improvement.
The distinction between a repair and an improvement has real tax implications. A repair gets deducted in the year it happens. An improvement must be added to the property’s cost basis and depreciated over a 39-year commercial schedule, unless it qualifies for cost segregation or bonus depreciation.
Who Pays for Property Improvements Under a NNN Lease?
Lease structure decides who writes the check. In a gross lease or a Class B office building, the landlord often absorbs improvement costs, since re-tenanting depends on a competitive space. In a double net (NN) lease, the landlord keeps responsibility for roof and structure while the tenant covers most operating costs. In an absolute NNN lease, the tenant owns almost every improvement question: roof, structure, HVAC replacement, and parking lot resurfacing all fall to the tenant under lease terms.
This distinction – the fact that tenants in an Absolute NNN Lease are responsible for most property improvements – is the primary reason we see buyers move their capital away from value-add multifamily or office assets and into a NNN lease investment. A landlord under an absolute NNN structure does not compete for capital between distributions and improvement reserves, because the reserve requirement stays minimal in practice.
Bonus Depreciation and Cost Segregation in 2026
Tax treatment changes the math on any improvement a buyer funds without a tenant offset. The One Big Beautiful Bill Act, signed into law on July 4, 2025, restored permanent 100% bonus depreciation for qualifying property placed in service after January 19, 2025. Combined with a cost segregation study, a buyer can reclassify components such as parking lots, signage, and land improvements into a 5, 7, or 15-year schedule instead of the standard 39-year commercial timeline. Our full breakdown of NNN lease tax benefits in 2026 covers the full set of deductions available this year.
For a buyer who plans to fund improvements without shifting that duty to a tenant, this tax treatment offers a meaningful offset to the cost.
Property Improvement and CAM: Where the Two Meet
It’s easy to confuse capital improvements and Common Area Maintenance (CAM) charges.
CAM covers routine maintenance and repair of shared areas, such as landscaping, snow removal, and parking lot sweeping.
A capital improvement, such as a full parking lot repave or a new HVAC unit, sits outside CAM in most leases and gets funded through a landlord’s improvement reserve or a tenant capital account instead. Our full guide to CAM reconciliation walks through how this process works and which expenses belong in each bucket.
A buyer who confuses the two categories during due diligence can misjudge a property’s true operating cost. A clear look at both the improvement schedule and the CAM history gives a fuller picture of total ownership cost.
Why Absolute NNN Buyers Carry Less Improvement Risk
Auto parts retailers illustrate the point well. Our comparison of AutoZone and O’Reilly NNN properties shows two of the strongest credit tenants in the sector, and in many of these deals the tenant covers roof, structure, and every other capital item under an absolute NNN lease. A buyer in this structure faces almost no exposure to a surprise capital call for a new roof or a parking lot rebuild, because the lease places that duty on the tenant from day one.
This same logic extends across a diversified NNN lease portfolio built from multiple sectors and tenants, such as dollar stores, auto parts, and quick-service restaurants. Spread the improvement question across several absolute NNN assets, and the portfolio-level exposure to unplanned capital cost stays low.
Is a NNN Property the Right Fit for Your Improvement Tolerance?
Not every buyer wants zero involvement in property improvement decisions. An investor who enjoys the process of upgrading a building and capturing forced appreciation may prefer a value-add retail center or a Class B office asset with room to improve. That investor accepts more work and more risk in exchange for potential upside beyond a corporate lease guarantee.
A buyer who wants predictable income, low landlord duty, and minimal exposure to capital improvement decisions tends to find a better match in an absolute NNN property. Our step-by-step guide on how to invest in triple net properties covers how to weigh this choice alongside cap rate, tenant credit, and lease term.
Ready to review a property’s improvement history and CAM records before you buy? Contact a Westwood Net Lease Advisor today for a no-obligation conversation at 314-997-5227. Our buyer representation comes at no cost to you, from the property search through closing.
