Cost Segregation on a 5-Unit Multifamily Property: Is It Worth the Study Fee?

The five-unit building is the first property where cost segregation becomes a real decision rather than an obvious yes or an obvious no. Below five units you are usually in single-family territory where the study fee eats the benefit. Above twenty units the answer is almost always yes. Five units sits in between.

The short version: a five-unit property with $700,000 or more of depreciable basis usually clears breakeven comfortably. Below roughly $400,000 of basis it often does not. The variable that decides it is not unit count. It is how much of your purchase price landed in the building rather than the land, and how much site work sits outside the walls.

What Actually Reclassifies in a Five-Unit Building

A five-unit property crosses into residential rental treatment under IRC Sec. 168(e)(2)(A), which means the structural shell depreciates over 27.5 years rather than 39. That shorter baseline is the reason small multifamily reclassification percentages look modest compared to commercial property. You are pulling assets out of a 27.5-year bucket, not a 39-year one, so each dollar moved is worth less than it would be on a strip center.

The five-year personal property under IRC Sec. 168(e)(3)(B) in a typical five-unit building includes the appliance packages in each unit, cabinetry and countertops that are not permanently affixed in a load-bearing way, window treatments, carpet and vinyl plank flooring, decorative lighting, and the dedicated electrical serving in-unit appliances. On five units that is real money but it is bounded. Five refrigerators, five ranges, five dishwashers, and five sets of cabinets is a finite list.

The fifteen-year land improvements under Sec. 168(e)(3)(C) are frequently the larger opportunity and the one owners underestimate. Parking areas, the curb cut and approach, exterior site lighting, fencing, retaining walls, landscaping and irrigation, the trash enclosure, sidewalks, and site drainage all land here. On a garden-style five-unit with surface parking, land improvements alone often run 8% to 12% of depreciable basis.

Typical Reclassification Range

Across five-unit properties we see total reclassification of 22% to 28% of depreciable basis. Newer construction with in-unit laundry, upgraded finishes, and substantial paved parking pushes toward the top of that band. A 1960s brick walkup on a tight urban lot with street parking and no site improvements lands nearer 18%.

The split within that range is usually 10% to 14% in five-year property and 8% to 14% in fifteen-year land improvements. Seven-year property is rare in residential rental and generally shows up only if there is a leasing office with dedicated furniture.

The Breakeven Math

Take a five-unit acquired for $1,150,000 with $250,000 allocated to land, leaving $900,000 depreciable. A study identifies $108,000 of five-year property (12%) and $99,000 of fifteen-year land improvements (11%), reclassifying $207,000 total. The remaining $693,000 stays on 27.5-year straight line.

Under IRC Sec. 168(k), that $207,000 is deductible in year one. The structural component contributes roughly $25,200. First-year depreciation comes to about $232,200 against approximately $32,700 on an unsegregated schedule. The additional first-year deduction is roughly $199,500.

At a 35% combined federal and state marginal rate, that is about $69,800 of tax deferred into year one. Against a study fee in the $4,000 to $6,500 range for a property this size, the return is not close. It works.

Now run the same math on a $400,000 basis. Reclassified basis is roughly $92,000 and the tax value is about $29,000. Still positive against a $4,000 fee, but the margin narrows enough that other factors start to matter. Our breakdown of what a cost segregation study actually costs covers how fees scale on smaller properties.

The Constraint That Kills Most Five-Unit Studies

The deduction is worthless if you cannot use it. A five-unit rental is a passive activity under IRC Sec. 469 unless you qualify as a real estate professional under Sec. 469(c)(7) or the property qualifies for short-term rental treatment. A W-2 earner with one five-unit building and no other passive income will suspend the entire loss and carry it forward.

That is not always fatal. Suspended losses release on a fully taxable disposition and offset passive income from other properties in the meantime. But if you are buying a five-unit expecting to shelter salary income, the answer is usually no. See our discussion of using cost segregation against W-2 income for the tests that have to be met.

You Do Not Have to Do It in the Year of Purchase

If you bought the building three years ago and skipped the study, the deduction is still available. Form 3115 under Rev. Proc. 2015-13 lets you change your method of accounting and claim the entire cumulative missed depreciation as a Sec. 481(a) adjustment in the current year, without amending prior returns.

On a five-unit this often produces a better outcome than doing the study at purchase would have, because the catch-up adjustment lands in whatever year you choose rather than the year you happened to close. Owners who had a low-income year at acquisition and a high-income year now should look hard at this timing.

Frequently Asked Questions

Is a 5-unit property big enough for cost segregation?

Usually yes if depreciable basis exceeds roughly $700,000. At that level a study typically reclassifies $150,000 to $200,000 and produces tax savings many times the fee. Below about $400,000 of basis the math gets thin and depends on how much site work the property has.

Why is the reclassification percentage lower than on commercial property?

Because a 5-unit is residential rental under IRC Sec. 168(e)(2)(A) with a 27.5-year structural life rather than 39 years. There is also simply less specialized equipment in an apartment building than in a restaurant or car wash. Expect 22% to 28% rather than 40% or more.

Can I use the deduction against my salary?

Only if you or your spouse qualify as a real estate professional under IRC Sec. 469(c)(7) with material participation, or the units are rented short term. Otherwise the loss is passive, gets suspended, and carries forward until you have passive income or sell the property.

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