The mechanics are straightforward but the bookkeeping discipline is where most investors fall short. Residential rental property depreciates over 27.5 years using the straight-line method. Commercial property uses 39 years. Both follow the same core principles, only the timelines differ.

Start with cost basis. Take the purchase price, subtract the land value (land does not depreciate), add qualifying closing costs, and add capital improvements made after purchase. That number becomes your building’s depreciable basis. Divide by 27.5 and you have your annual depreciation expense for a residential rental.

Allocating land versus building trips up most investors. The IRS accepts a few methods. The most common is using your county property tax assessor’s ratio. If the assessment shows 20% land and 80% improvements, apply that same ratio to your purchase price. An independent appraisal gives stronger documentation when the allocation is significant or the assessor ratio seems off.

Not every closing cost adds to basis. Title insurance, legal fees, recording fees, and transfer taxes typically do. Prorated property taxes and loan origination costs usually don’t. Your settlement statement lists everything in one place, but the items don’t all get the same treatment.

Track each property separately. Maintain a fixed asset register per property showing purchase date, original cost basis, land allocation, depreciable basis, accumulated depreciation, and net book value. QuickBooks can handle this through fixed asset accounts and depreciation journal entries, but investors with multiple properties often benefit from a supporting spreadsheet or software built for rental accounting. The real estate investor clients we work with usually run a schedule per property that rolls up to portfolio-level reporting.

Capital improvements extend an asset’s life or add value. A new roof, HVAC system, or addition gets capitalized and depreciated. Repairs keep the property running as-is and get expensed in the year incurred. The distinction matters. Capitalizing a true repair costs you a current deduction, and expensing a real improvement creates audit risk.

Cost segregation studies can meaningfully accelerate depreciation. Instead of depreciating the entire building over 27.5 years, an engineering-based study identifies components that qualify for 5, 7, or 15-year schedules. Appliances, carpet, certain electrical and plumbing, landscaping, and parking lot improvements often qualify. For larger properties or investors in high tax brackets, the upfront study cost typically pays for itself in the first year or two through tax savings.

Depreciation reduces taxable income now but creates recapture when you sell. The IRS reclaims some of that deferred tax at a 25% rate on the depreciation you claimed or could have claimed. Planning for recapture, or using strategies like 1031 exchanges to defer it, should factor into your decisions years before you list a property.

The Pasadena bookkeepers at A Squared come from a real estate accounting background, so depreciation tracking, capital versus repair classification, and coordinating with your CPA on cost segregation are familiar territory. Books that don’t properly track basis and accumulated depreciation create problems at tax time and bigger problems at sale, which is when clean records matter most.