Mixed-Use Properties: Allocating Depreciation and Deductions

Mixed-use properties require careful allocation between residential and commercial portions to maximize depreciation benefits and passive activity planning.

You must allocate between residential and commercial portions. The IRS requires reasonable allocation of the purchase price, expenses, and improvements between the residential and nonresidential portions of a mixed-use building. This allocation drives everything else: the residential portion depreciates over 27.5 years while the commercial portion depreciates over 39 years.

Two depreciation schedules run simultaneously. Each portion has its own placed-in-service date, cost basis, and recovery period. Shared systems -- a roof, foundation, or HVAC serving both portions -- must be allocated proportionally, typically by square footage or rental income.

Expense allocation follows the same split. Property taxes, insurance, and common-area maintenance must be divided between the residential and commercial portions. Expenses specific to one portion (a commercial tenant build-out, a residential appliance replacement) are tracked separately.

Partial 1031 exchanges are possible but require precision. You can exchange the commercial portion of a mixed-use property while selling the residential portion outright (or vice versa). This requires proper allocation of the sales price and separate identification of replacement property for the exchanged portion.

The pitfall: An incorrect initial allocation between residential and commercial portions compounds through every year of ownership. If the IRS challenges the split, it can trigger depreciation recapture and recomputation of every prior return. Getting the allocation documented and defensible at acquisition is critical.