While it isn't easy to expand your property, you can consider building up. The cost of adding a second story has quite the range. We'll break it down here.
How Much Does It Cost to Build a Fourplex? [2025 Data]
Normal Range: $400,000 - $1,000,000
The average cost to build a fourplex ranges from $400,000 to $1,000,000, with most homeowners spending $750,000. Main cost factors include size, materials, labor, and location.
How we get this data
Photo: Monkey Business / Adobe Stock Photography
Photo: Monkey Business / Adobe Stock Photography
Cost Insights
The average cost to build a fourplex is $750,000, with most projects ranging from $400,000 to $1,000,000 and national costs spanning $300,000 to $1,300,000.
Construction, including foundation, framing, roofing, and exterior, typically costs between $220,000 and $600,000, while materials add another $100,000 to $300,000.
Labor for skilled and general work usually runs $60,000 to $200,000, and permits and fees cost around $10,000 to $40,000.
Fourplex size strongly affects total cost, with 3,000 square feet ranging between $400,000 to $600,000 and 5,000 square feet costing $900,000 to $1,200,000.
Hiring additional pros, such as a general contractor, architect, or structural engineer, adds $8,000 to $25,000 for plans and 10–20% of total construction costs for project management.
This article was created using automation technology and thoroughly fact-checked and edited by an Angi Editor in accordance with our AI policy.
The cost to build a fourplex ranges from $300,000 to $1,300,000, with an average of $750,000. Expect to pay between $120 and $300 per square foot, depending on location, materials, and design complexity. Understanding these costs helps you budget for your multi-unit investment and make informed decisions about your project.
Fourplex Cost Breakdown
Let’s look at what makes up the total price tag for a new fourplex. Your biggest expenses include construction, materials, labor, permits, and site preparation. Most fourplexes cost between $120 and $300 per square foot to build, depending on choices like layout, finishes, and whether you select a turnkey or shell-only build.
Standard designs and finishes help keep costs on the lower end, while custom layouts, luxury materials, and advanced systems can increase costs. A turnkey fourplex includes everything from foundations to final finishes, while a shell-only build covers just the structure and leaves interior completion to you.
| Cost Category | Description | Average Cost Range |
|---|---|---|
| Construction | Foundation, framing, roofing, exterior | $220,000–$600,000 |
| Materials | Lumber, insulation, windows, and doors | $100,000–$300,000 |
| Labor | Skilled and general labor, project management | $60,000–$200,000 |
| Permits & fees | Building, zoning, utility, and impact fees | $10,000–$40,000 |
| Site prep | Clearing, grading, and soil testing | $10,000–$30,000 |
| Utilities & hookups | Water, sewer, electricity, and gas connections | $15,000–$40,000 |
| Finishes | Flooring, cabinetry, appliances, paint | $40,000–$120,000 |
Cost by Size of Fourplex
The size of your fourplex plays a major role in the total cost. Larger buildings require more materials, labor, and time. Most fourplexes fall between 3,000 and 5,000 square feet, with costs scaling up as you add square footage or opt for a multi-story design.
Cost per unit and cost per square foot are useful benchmarks. For example, a 4,000-square-foot fourplex at $200 per square foot totals $800,000. Adding high-end features or additional stories will raise both the per-unit cost and the overall price.
| Fourplex Size (Sq. Ft.) | Description | Average Cost Range |
|---|---|---|
| 3,000 | Compact, single-story units | $400,000–$600,000 |
| 4,000 | Average size, 2-story design | $600,000–$900,000 |
| 5,000 | Spacious, luxury features | $900,000–$1,200,000 |
Fourplex Pro Costs
Building a fourplex requires a team of skilled professionals. General contractors oversee the project and charge between 10% and 20% of the total construction cost. General contractor fees cover labor management, scheduling, and material sourcing. An architect or designer will create your fourplex plans, charging $8,000 to $25,000 based on the project’s complexity.
A structural engineer ensures your building meets safety standards, with fees from $2,500 to $8,000. Regional differences in labor rates and demand can affect what you pay. It’s best to hire each pro at the right stage: architects and engineers early for planning, and general contractors for the build.
Additional Pros to Consider Hiring
Depending on your site and project, you may need additional experts:
Land surveyor fees: $500 to $2,000 for mapping boundaries and elevations.
Civil engineer: $2,000 to $7,000 for site drainage, grading, and utility planning.
Landscape architect: $2,000 to $8,000 to design outdoor spaces.
Interior designer fees: $3,000 to $10,000 for selecting finishes and layouts.
Environmental consultant: $1,000 to $4,000 for soil, water, or hazard assessments.
Cost by Location
Where you build your fourplex has a significant impact on your costs. Urban areas often experience higher prices due to higher labor rates, increased demand, and stricter building codes, while rural locations may be less expensive but face higher transportation and material delivery costs. Suburban sites often fall in the middle.
Local labor rates, material availability, and city or state building codes can quickly affect your budget. For example, seismic or hurricane zones require additional reinforcements, adding to expenses.
Additional Cost Factors
Beyond construction and labor, several other expenses can impact the total cost of building a fourplex. Taxes, builder’s risk insurance, and extended warranties may be necessary. Special features, such as smart home technology, green building upgrades, or ADA accessibility, can add to the budget. Repairs and post-construction cleanup ensure the building is move-in ready, but bring additional costs.
Demolition and Prep
If you’re replacing an existing structure, demolition costs between $10,000 and $40,000, depending on the size and materials. For vacant lots, site clearing, grading, and soil testing costs range from $5,000 to $20,000. Redeveloping an existing property often means higher preparation costs, especially if old utilities or foundations need to be removed.
Permits
Fourplex construction requires multiple permits, including building, zoning, electrical, plumbing, and utility permits. Your contractor often manages this process, but some homeowners handle it themselves. Permit fees for a fourplex range from $10,000 to $40,000, depending on location and scope. The process can take several weeks to months, and you’ll need inspections at key stages to stay code-compliant.
Why You Should Hire a Fourplex Building Pro
Hiring a local custom home building pro for building a fourplex costs more upfront, but you benefit from proper construction techniques, adherence to building codes, and efficient project management. Pros bring the right equipment—such as heavy machinery, scaffolding, and specialized tools—and the experience needed to construct a multi-unit building safely and efficiently.
Here’s why it’s ideal to hire a fourplex construction pro:
Pros know how to manage all phases of construction, from site preparation and foundation work to framing, roofing, and finishing, ensuring a structurally sound and code-compliant building.
They handle permits, inspections, and adherence to local building codes, which can be complex and vary by jurisdiction, reducing the risk of legal or regulatory issues.
Hiring a pro reduces the risk of construction errors, delays, or cost overruns that could compromise safety or long-term value.
Many contractors can bundle services such as utility installation, landscaping, and interior finishes, helping streamline the entire construction project.
| Approach | Description | Average Total Cost |
|---|---|---|
| DIY | Homeowner manages/subcontracts all work | $300,000–$700,000 |
| Pro | Licensed GC manages the project from start to finish | $400,000–$1,200,000 |
Fourplex Remodel vs. Renovate
It’s important to distinguish between remodeling, renovating, and building new. Remodeling involves changing layouts or making structural modifications, such as combining units or adding square footage. Renovating is about refreshing finishes, fixtures, or restoring a building’s condition.
Renovating an existing fourplex (updating kitchens, baths, or flooring) costs less than a complete remodel or new build. Remodeling (reconfiguring units or upgrading systems) is more expensive, often approaching the costs of new construction. Choose renovation for cosmetic updates, remodeling for major changes, and new builds for the greatest flexibility and long-term value.
Tips to Reduce Costs While Building a Fourplex
Here are a few helpful ways to save on your fourplex project:
Choose standard plans over custom designs to avoid design and engineering premiums.
Source materials in bulk or at wholesale rates to secure lower prices.
Limit high-end finishes to focal areas, such as kitchens and main living spaces.
Manage some project phases yourself if you have relevant experience.
Obtain multiple bids from contractors to find the best balance of price and quality.
Consider energy-efficient upgrades that save on utilities over time.
Plan for future expansion or upgrades during the initial construction.
Does Building a Fourplex Increase Property Value?
Building a fourplex can significantly increase your property value and offer strong rental income potential. ROI for fourplex construction often outpaces that of single-family or duplex properties, especially in high-demand rental markets. Location, thoughtful design, and desirable amenities all drive value and appeal.
A well-built fourplex can provide steady cash flow, flexibility for future resale, and long-term appreciation. The combination of multiple income streams and higher-density land use makes it an attractive investment for many homeowners.
Next Steps: Finalize Your Project With a Custom Home Builder
Let your contractor know the size, layout, and number of units you plan to build, so they can plan for the right materials, labor, permits, and timeline.
Describe any underlying site issues you’ve noticed, like drainage problems, soil instability, or existing utility lines, that could affect construction or require additional work.
Ask whether you need to prep the site beforehand, such as clearing vegetation, grading, or relocating utilities.
Confirm whether unexpected costs could arise from issues like foundation challenges, zoning or code requirements, or difficult access for construction equipment.
If you’re considering additional work—like landscaping, parking areas, or common area improvements—ask whether it’s more efficient to bundle those services with the fourplex construction.
How Angi Gets Its Cost Data
Home is the most important place on earth, which is why Angi has helped more than 150 million homeowners transform their houses into homes they adore. To help homeowners with their next project, Angi provides readers with the most accurate cost data and upholds strict editorial standards. We extensively research project costs to develop the pricing data you see, so you can make the best decisions for you and your home. We rely on reputable sources, including the U.S. Bureau of Labor Statistics, academic journals, market studies, and interviews with industry experts—all to ensure our prices reflect real-world projects.
Want to help us improve our cost data? Send us a recent project quote to [email protected]. Quotes and personal information will not be shared publicly.
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