Multifamily is residential real estate that houses more than one household in separate units within a single building or complex. In U.S. lending, zoning, and appraisal practice, a property with five or more units is treated as commercial, while two-to-four-unit properties qualify for residential financing. It spans duplexes through large apartment communities.
What Is Multifamily Real Estate?
Multifamily real estate is any residential building or complex with two or more self-contained units that separate households can rent or own. The defining line in commercial practice is the five-unit threshold: a property with five or more units is classified as commercial and requires commercial financing, while two-to-four-unit properties qualify for conventional residential loans.
That threshold sets everything downstream. Below five units, a buyer can use FHA, Fannie Mae, or Freddie Mac residential programs underwritten to personal income. At five units and above, the loan is underwritten to the property's net operating income and debt service coverage, and the asset is valued by income rather than by residential comparable sales. The table shows how the segment breaks down.
Segment | Units | Classification |
Duplex, triplex, fourplex | 2 to 4 | Residential financing |
Small apartment | 5 to 49 | Commercial |
Mid-size apartment | 50 to 150 | Commercial, institutional interest |
Large / garden community | 150+ | Commercial, institutional |
Why Multifamily Matters
Multifamily matters because it is the most liquid and consistently financed commercial property type, backed by demand that does not disappear in a downturn. In Q1 2026, CBRE reported the U.S. multifamily vacancy rate fell to 4.8% as net absorption reached 78,100 units, the first quarter in three where demand outpaced completions.
That stability shows in pricing. In CBRE's H2 2025 U.S. Cap Rate Survey, Class A multifamily averaged roughly 4.74%, Class B roughly 4.92%, and Class C roughly 5.38%, tighter than most other property types. For an operator, multifamily's short lease terms are the key mechanic: leases reset every 12 months, so rents reprice to the market quickly, which protects income during inflation but exposes it fast when demand softens. Underwriting hinges on the rent roll, unit mix, and the gap between in-place and market rent.
Example
A 100-unit Class B apartment community averages $1,650 in monthly rent per unit at 95% occupancy. The worked figures below carry gross potential rent through to value at a 5.0% cap rate.
Component | Value |
Units | 100 |
Average monthly rent | $1,650 |
Gross potential rent (annual) | $1,980,000 |
Vacancy loss (5%) | $99,000 |
Effective gross income | $1,881,000 |
Operating expenses (45%) | $846,450 |
Net operating income | $1,034,550 |
Gross potential rent is 100 units times $1,650 times 12 months, or $1,980,000. A 5% vacancy loss of $99,000 leaves effective gross income of $1,881,000. Subtract 45% operating expenses of $846,450 to reach a net operating income of $1,034,550. At a 5.0% cap rate near the Class B average, implied value is $1,034,550 divided by 0.05, or about $20.7 million, roughly $207,000 per unit.
Variations and Edge Cases
Multifamily behaves differently by structure, unit count, and subsidy, so the same building can carry a different financing and tax profile. The table lists variants an underwriter should confirm before pricing a multifamily asset.
Variant | Treatment |
2 to 4 units | Residential financing, valued by comparable sales, not income |
Garden vs mid-rise vs high-rise | Construction type drives cost, density, and expense ratio |
Affordable / LIHTC | Rent caps and compliance in exchange for tax credits |
Student or senior housing | Specialized demand and operations despite multifamily structure |
Build-to-rent single-family | Detached homes operated as one rental community |
The most common error is applying residential loan assumptions to a five-plus-unit building. At five units the asset is commercial and is underwritten to income and debt service coverage.
Multifamily vs Single Family Rental
Multifamily is often confused with single-family rental, and the two differ in structure and how they are financed. Multifamily is one building or complex with multiple separate units, treated as commercial at five or more units. A single-family rental is one detached home leased to one household and financed and valued as residential regardless of how many an investor owns.
The distinction drives valuation. Multifamily of five-plus units is priced on net operating income and a cap rate, so an operator adds value by raising rents or cutting expenses. A single-family rental is valued mainly by comparable home sales, so its price tracks the local housing market more than its rent stream.
Frequently Asked Questions
What is a multifamily property?A multifamily property is residential real estate with two or more self-contained units for separate households, from a duplex to a large apartment community. A property with five or more units is treated as commercial and requires commercial financing, while two-to-four-unit properties qualify for residential loans.
When is multifamily considered commercial?Multifamily is considered commercial at five or more units. At that threshold the property is financed with commercial loans underwritten to net operating income and debt service coverage, and it is valued by income rather than by comparable residential sales. Two-to-four-unit properties remain residential.
Is multifamily a good investment?Multifamily is among the most stable commercial property types. In Q1 2026, CBRE reported U.S. multifamily vacancy at 4.8% with 78,100 units of net absorption, and Class B cap rates near 4.92% in CBRE's H2 2025 survey, tighter than most other property types.
Related Terms
Cap Rate
Net Operating Income
Vacancy Rate
Rent Roll
Loss to Lease