The total cost to build a fourplex is around $300,000 to $1,300,000. Most projects land near $750,000. That’s roughly $85,000 to $260,000 per unit. The cost of a fourplex on a per square foot basis is approximately $120 to $300. The above range is dependent on your market, your finishes and whether you are creating a simple design or something more custom. Fourplex construction cost does not include the land, permit and site prep. Those cost extra and sit on top of the total number, not inside it.
Three things change the price the most:
- Where you build
- What the homes look like inside
- How strict your city’s permit office is
If you want a number you can trust, talk to professional residential estimating services. They can give you a real quote based on your land, local construction conditions and your plans.
What Is a Fourplex?
A fourplex is one building with four homes in it. Each home has its own front door. Each home has its own kitchen and bathroom too. The four homes share one roof and outside walls.
You can think of it as four small houses joined into one building. Some owners live in one home and rent out the other three. Others rent out all four. That’s why landlords prefer fourplexes.
Cost Breakdown: How Much Does it Cost to Build a Fourplex?
Here’s what you’re really paying for.
| Cost Component | Rough Cost |
| Cost per square foot | $120-$300 |
| Cost per unit | $85,000-$270,000 |
| Land | Changes by City |
| Foundation | $25,000-$55,000 |
| Framing | $80,000-$150,000 |
| Roof | $20,000–$45,000 |
| Plumbing | $30,000-$60,000 |
| Electrical | $25,000-$50,000 |
| Heating and cooling | $20,000-$45,000 |
| Walls and insulation | $25,000-$50,000 |
| Finishes | $25,000-$50,000 |
| Permits and fees | Often 30%-40% of the total |
| Workers’ pay | Built into the costs above |
| Plans and design | $10,000–$30,000 |
These figures are subject to change and are only approximate. Look at national fourplex construction cost data to get an idea. They collect real numbers from builders and estimators all over the country. The final cost always depends on your city, the land and the design of the house.
Is it cheaper to build a fourplex than to buy an existing one?
It depends upon the area. Building your own may be a wise way to save money if homes are high-priced in your area. Before deciding, make a comparison between the costs of building locally and the resale prices.
What Are the Factors That Affect Fourplex Construction Costs?
Six factors change the price most. These factors are given below.
Land and Location
Land in the city costs more. Cities also have stricter rules and slower approvals. Land in rural areas costs less. But you may need to run new power and water lines out there. That can cost a lot too.
Design and Layout
A simple footprint with a shared roofline costs less than a custom design with varied rooflines or multiple stories. The Fourplex cost per square foot is less than side-by-side townhouse layouts.
Foundation and Framing
This is the base of the building. The foundation work alone for the entire building is $25,000 to $55,000. If the soil is difficult or a basement is required, that number will increase.
Finishes
These are things like floors and counters. Plain floors cost less. Simple fixtures cost less too. Wood floors cost more. Stone counters cost more. Fancy cabinets cost more. These can add to the overall fourplex cost per unit.
Permits and Regulations
This one surprises people. The permitting process, delays and fees account for about 40% of the total cost of the construction of multifamily housing. This is confirmed by a 2022 survey from the National Association of Home Builders (NAHB) and the National Multifamily Housing Council (NMHC). In jurisdictions that have slow permitting departments or impact fees, it can also cost real dollars before a single wall is raised.
Labor and Materials
Paying workers and buying materials make up about 64% of what a new home costs today. Two years ago, in 2022, it was about 61% as per NAHB’s latest Cost of Construction Survey (NAHB). Workers and materials increase the cost significantly.
Fourplex vs. Four Single-Family Homes: Which Is Cheaper to Build?
The cost to build a fourplex is much less as compared to the 4 single houses built on the same square foot. It is because you’re sharing walls, one roof, and one set of utility trenches instead of paying for four of everything.
To understand and decide what type of property to build, see how that compares to building a single-family home.
| Factor | Fourplex | 4 Single-Family Homes |
| Foundation | One shared foundation | Four separate foundations |
| Roof | One roof system | Four separate roofs |
| Utility lines | Combined trenching | Four separate hookups |
| Per-unit cost | 30%–40% lower | Full price, no sharing |
| Design flexibility | Shared structural grid | Each home can differ |
| Land needed | Less land per unit | More land per unit |
Turnkey vs. Shell-Only: Which Costs Less?
Shell-only costs less upfront, but it shifts finishing costs onto you later. A shell-only build gives you just the structure, roof, and exterior. Turnkey costs more upfront but it covers everything from foundation to final light fixture.
| What You Get | Turnkey | Shell-Only |
| What’s included | Everything, start to finish | Just the frame, roof, and outside walls |
| Move-in ready? | Yes | No, you finish it later |
| Upfront cost | Higher | Lower |
| Total cost over time | About the same | About the same, just spread out |
| Best for | Buyers who need it done fast | Investors who want to finish it in stages |
| Loan-friendly | Yes, easier to finance | Sometimes harder to finance |
Fourplex vs. Duplex Cost: Which Costs Less to Build?
A duplex is a building of two homes. A duplex costs less overall while a fourplex costs less per unit. A duplex works better if you’ve got a smaller lot or a smaller budget. A fourplex needs more land and more money upfront.
| Factor | Duplex (2 units) | Fourplex (4 units) |
| Average total cost | $402,000 | $750,000 |
| Cost per square foot | $115–$240 | $120–$300 |
| Cost per unit | $150,000–$275,000 | $95,000–$250,000 |
| Rental income streams | 2 | 4 |
| Land needed | Smaller lot | Larger lot |
| Financing type | Conventional/FHA | Conventional/FHA (up to 4 units) |
Every fourplex is different. Get a clear cost estimate based on your plans, location, and project details before you set your final budget.
Conclusion
A fourplex is a smart and cost-saving way to build rental income. You’re spreading land, permits, and structural costs across four units instead of one. Your real cost to build a fourplex depends on your city, your land, and how nice you want the units to be.
Don’t build your budget around online averages alone. Get real price quotes from a licensed local builder. Check your city’s fees before you finish your design. And decide early if you want turnkey or shell-only. These three choices will change your final cost the most.
