How Much Does It Cost to Build a Fourplex? (2026)

The fourplex is the last stop before commercial multifamily — four rent checks, still on a residential loan. In 2026, a fourplex typically costs $520,000 to $1,450,000 all-in to build, before land.

That's roughly $130–$240 per square foot and $130,000–$320,000 per unit. Four units spread fixed costs the furthest of any residential build, which is why per-unit numbers here are usually the lowest.

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$130k–$320k per unitResidential financing ceilingRepeating-unit savings

How Much Does It Cost to Build a Fourplex? (2026)

2026 cost dataBest per-unit value

Why the fourplex is the financing sweet spot

Up to four units is still residential in U.S. lending — build a fourplex, live in one unit, and you can potentially use owner-occupant financing with a much lower down payment.
Three tenants help cover your mortgage while you occupy the fourth unit.
Add a fifth unit and you cross into commercial underwriting overnight — which is why so many investors build to exactly four.

Where fourplex budgets go

Envelope & structure (foundation, framing, roof, exterior) — about 35–45% of the build.
Interior finishes — 25–35%, multiplied across four kitchen and bathroom sets.
MEP — 15–20%, with four separately metered services.
Site work & permits — the balance.
Repeating the same unit plan four times is the single biggest cost saver — it turns custom carpentry into an assembly line.

Typical all-in fourplex build cost by size (2026)

Fourplex size	All-in build cost	Est. per unit
Compact — 4 × ~1,000 sq ft (~4,000 total)	$520k – $900k	$130k – $225k per unit
Standard — 4 × ~1,300 sq ft (~5,200 total)	$650k – $1.15M	$162k – $287k per unit
Large — 4 × ~1,600 sq ft (~6,400 total)	$820k – $1.45M	$205k – $362k per unit

Excludes land. 2026 construction ranges. Local labor rates and code (especially fire and parking) shift these materially — run an instant cost report for a ZIP-adjusted number.

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Frequently asked questions

How much does it cost to build a fourplex per unit?+

Typically $130,000–$362,000 per unit in 2026, with compact, repeating-plan designs at the low end. Per-unit cost on a fourplex is usually the best in the 2–4 unit range because fixed costs spread across four units.

Can I get an FHA or residential loan on a fourplex?+

Yes. Up to four units is residential, so owner-occupant products (including low-down-payment options) can apply if you live in one unit. A fifth unit moves you to commercial financing.

Is a fourplex cheaper per unit than a duplex?+

Usually. Spreading one permit, one foundation footprint and one crew mobilization across four units instead of two lowers the per-unit share, and repeating the unit plan drives finish costs down further.

Does the estimate include land and parking lot work?+

No. Figures are construction of the building only. Land, paving and extensive site work are separate and vary widely by location.

Design a fourplex that maximizes every unit

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