An apartment complex, generally meaning a property of five units or more where financing shifts from residential to commercial underwriting, is a different investment than a duplex or fourplex in nearly every respect: how it's financed, how it's valued, and how much operational infrastructure it requires. Washington investors moving up from smaller rental property into a complex-sized acquisition should expect the underwriting process itself to change, not just the price tag.
Where the Five-Unit Line Changes Everything
Once a property crosses from four units to five, conventional residential financing is no longer available, and the loan shifts to commercial multifamily underwriting, which values the property primarily on its net operating income rather than comparable sales of similar houses. That valuation method, income divided by a market cap rate, means an apartment complex's price is far more sensitive to its actual rent roll and expense ratio than a single-family comparable would be, and a buyer needs a real operating statement, not just a rent estimate, to underwrite it correctly.
Commercial Financing Terms Differ From Residential
Commercial multifamily loans typically require a debt service coverage ratio, usually 1.20 to 1.25, meaning net operating income must exceed the mortgage payment by that margin, along with a larger down payment than a residential loan, often 25 to 30 percent. Lenders will also scrutinize the trailing twelve-month operating statement closely, and a complex with thin or unverifiable financial records can face a longer underwriting timeline or a lower loan amount than the purchase price would suggest.
- Debt service coverage ratio typically required: 1.20 to 1.25
- Typical down payment: 25 to 30 percent
- Underwriting basis: trailing operating statement, not comparable sales
Operational Scale Changes the Ownership Experience
A twenty-unit or larger complex generally needs either on-site or regularly scheduled property management, whereas a fourplex owner can often self-manage. Washington complexes in Seattle, Tacoma, and Spokane commonly budget property management at 4 to 8 percent of gross rent, plus a payroll or contract line for maintenance staff on larger properties, expenses a smaller rental simply doesn't carry.
Due Diligence Scope Grows With Unit Count
A larger complex means a longer due diligence checklist: unit-by-unit interior inspections or a representative sample, a full review of service contracts and any existing property management agreement, utility billing structure across the property, and confirmation of any pending or historical code violations with the local jurisdiction. Buyers moving into complex-sized acquisitions for the first time sometimes underestimate how much longer this process takes than inspecting a fourplex, and a rushed due diligence period on a large complex can miss issues that only surface after closing.
Washington's landlord-tenant statute also requires specific notice periods before a buyer can adjust rents or change lease terms after acquiring an occupied building, and those notice periods should be built into the first-year operating plan rather than assumed away. A buyer who plans to reposition a complex quickly after closing needs a realistic timeline for exactly how fast leases can actually turn under state law.
Third-Party Management Becomes Necessary, Not Optional
Somewhere between a duplex an owner manages personally and a two-hundred-unit complex, self-management stops being realistic for most investors, both because the time demand grows and because the operational systems, maintenance dispatch, rent collection, vacancy marketing, need to scale in ways a spreadsheet and a personal phone number can't handle indefinitely. Selecting a management company with real experience in complex-sized Washington multifamily, not just single-family or small rental management, tends to matter more to long-term performance than the specific fee percentage charged.
Apartment Complexes as Exchange Replacement Property
Investors selling a smaller rental property or a single commercial building sometimes exchange up into a larger apartment complex specifically to access the income-based financing structure and diversify tenant risk across dozens of units rather than a handful. Identifying a complex-sized replacement within the 45-day window means having audited or at least verified financials in hand quickly, since lenders won't move forward on unverified numbers and the 180-day closing period doesn't pause for a slow financial review.
Common Questions
At what point does a rental property become an apartment complex for financing purposes?
Generally at five units, where financing shifts from residential to commercial multifamily underwriting and valuation moves from comparable sales to net operating income.
What down payment is typical for an apartment complex loan?
Commercial multifamily loans typically require 25 to 30 percent down, higher than the 20 to 25 percent common on smaller residential investment financing.
Why does the operating statement matter more for a complex than a duplex?
Because commercial multifamily is valued primarily on net operating income divided by a market cap rate, so an unverifiable or thin operating statement directly affects both the appraised value and the loan amount a lender will offer.
Can an apartment complex be used as 1031 exchange replacement property?
Yes, as real property held for investment or business use. Investors often exchange up into a complex from a smaller rental specifically for income-based financing and broader tenant diversification.
What operating costs does a larger complex carry that a small rental doesn't?
Property management, typically 4 to 8 percent of gross rent, and often payroll or contract costs for on-site or regularly scheduled maintenance staff, neither of which a self-managed fourplex usually needs.