How Much Does It Cost to Build a Duplex?

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Written By Tommy

DealBloom aims to share the latest tips and strategies to help realtors, brokers, loan officers, and investors navigate the world of real estate.

If you’re looking to build a duplex, you might wonder, “how much does it cost to build a duplex?” This blog post will discuss the costs of building a duplex, including the factors that affect these costs.

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How Much Does it Cost to Build a Duplex?

So, how much does it cost to build a duplex? The answer, of course, depends on several factors – the size and location of the property, the materials used, and so on. But in general, building a duplex can cost anywhere between $200,000 and $350,000.

Duplexes can be a great investment, as they can provide rental income and appreciate over time.

Cost Per Square Foot for Building a Duplex

The cost per square foot for building a duplex can vary greatly depending on the materials used, the location, and the project size. However, on average, you can expect to pay somewhere between $95 and $220 per square foot.

Considering building a duplex, it’s important to factor in the cost per square foot so you can budget accordingly. For example, if you’re planning on building a 1,000-square-foot duplex, you can expect to pay between $100,000 and $200,000.

Of course, the cost per square foot will also vary depending on your materials. You can expect to pay more per square foot if you use higher quality materials. However, using higher-quality materials can also increase the value of your duplex, so it’s important to weigh the pros and cons before making a decision.

No matter what, it’s important to do your research and budget carefully before building a duplex. By understanding the cost per square foot, you can be sure you’re getting the most bang for your buck.

What Factors affect the Cost of Building a Duplex?

When building a duplex, it’s important to think about all aspects, such as:

Material type

The different types of products available, from cheap to expensive, would greatly impact the total cost of a project and the quality of the finished product.

The duplex size  

The remaining cost after materials is relative to the size of your structure.

Number of rooms

The number of units being constructed would signify greater materials costs, raising the cost of building a duplex.

The building’s design

Whether you or a professional build your home, you can construct it from the ground up with basic building materials or use prefabricated materials like doors, windows, and kitchens. Using premade materials is cheaper and faster, but the quality may be compromised.


Rates of labor and products will vary widely depending on where you live.

The contractor 

Those responsible for completing a job usually get a significant chunk of the final price.

Professional costs

The architect or engineers hired by the contractor or by you as the owner of the building will determine how much it will cost.

Pre-existing structure 

The presence of an existing structure before the construction of a new one would greatly affect the project’s overall cost. You can either save money by continuing or remodeling the existing one or spend more on demolishing or removing it from the construction site.

Ways to Save Money When Building a Duplex

As someone who has just gone through the process of building a duplex, I know firsthand how easy it is to spend more money than you need to. If you’re not careful, the costs can quickly add up, leaving you with an empty bank account and a half-finished project.

Here are a few ways to save money when building a duplex:

1. Shop around for materials

Don’t just buy the first batch of lumber or concrete, you see. Get quotes from multiple suppliers to ensure you’re getting the best price.

2. Hire local labor

If you can find workers close by, you’ll save on travel costs and support the local economy.

3. Do some of the work yourself

If you’re handy and have building experience, take on simpler tasks to save on labor costs.

4. Be flexible with your design

If you’re willing to make some changes to your original plans, you may be able to save money on materials or labor.

5. Shop for financing

Don’t just accept the first loan offer you get. Shop around and compare interest rates to get the best deal.

Duplex vs. two Houses: Which is Cheaper to Build?

People commonly build a duplex to rent half to tenants, while the other half is for the owner to live in. Other reasons to build a twin home include housing family members, friends, or financial purposes. Building a new house on another property can cost more but provides the same benefits.

While duplexes have only one building, they consist of two distinct living spaces. This makes them more expensive to construct than a single home, but not very much. If you built a house for each unit, you would have to pay for separate foundations, roofing, and walls. This would cost significantly more.

Building a Duplex is 63% cheaper than building two different homes. This is because a single-family home needs its lot, but a duplex only requires one. The land required to build a home can be expensive, so you can save a ton of money by building a home on shared land.

The Pros & Cons of Owning a Home

As with any real estate investment, owning a Duplex has its benefits and disadvantages. Before buying a property, weigh these considerations.

Duplex advantages

  • You have passive income from renting out either your duplex’s unit(s). This is one of the main reasons why many real estate investors buy and rent out a duplex.
  • You can live in one unit of a two-unit property while renting out the other. This rental income can pay your mortgage and let you “live free.”
  • You’ll enjoy some landlord tax benefits on half or all of the rental property.
  • A duplex is fairly easy to qualify for, especially if you’re purchasing it to live in. You might also be able to qualify for a loan through Federal Housing Administration(FHA), which requires you to put down very little money.
  • Duplex houses can be more enticing to potential residents than apartments. This may mean you can demand a higher monthly rent and can attract higher quality tenants.
  • Because there are two separate units of the same property, the vacancy risk is decreased. If you rent them separately, the chance of both being empty simultaneously is lowered.
  • Duplexes tend to appreciate in value over time, especially if they’re well maintained.
  • Duplexes can be great homes for a variety of people. You can live there, rent both units out, or move into one and rent out the other. You can even let your relatives live with you. Or, you can rent out the entire duplex on a short-term basis.

Duplex disadvantages

  • Since duplex homes are less desirable to tenants than single-family homes, you may be forced to lower rent prices. This may also limit your pool of potential applicants.
  • Not all areas allow duplex homes, so you may have to compromise on location outside of your preferred neighborhood.
  • If occupied by the owner, you’ll be sharing walls with renters and being easily accessible to them.
  • When a whole home repair is needed, you could end up paying a hefty sum for labor and materials, and both homes will be disrupted.

Is it Worthwhile to Own a Duplex?

A Duplex is a property with two dwellings that are attached. The owner can rent out one side while living there, or they can live in both. Renting out both generates monthly income. Therefore, it is possible to make a lot of cash by owning one.

Frequently Asked Questions

Is building a duplex a good investment?

There is no definitive answer to this question as it depends on several factors, including the location of the duplex, the quality of construction, and the current market conditions. However, building a duplex can be a good investment as it can provide rental income and appreciation in value over time. Additionally, the cost of building a duplex is typically lower than building two single-family homes.

What is the average size of a duplex?

There is no definitive answer to this question, as the average size of a duplex can vary greatly depending on the location and specific circumstances. However, according to HomeAdvisor, the average cost to build a duplex in the United States is $84,000.

How much does it cost to build a duplex in Washington state?

There is no definitive answer to this question in Washington state. The cost of building a duplex in Washington state will vary depending on several factors, including the size and location of the property, the materials used, and the labor costs. However, according to some estimates, building a duplex in Washington state can cost anywhere from $150,000 to $300,000.

How much does it cost to build a duplex in Nigeria?

In Nigeria cost of building a duplex can vary depending on the size and location of the property. However, building a duplex in Nigeria would cost approximately $30,000 to $40,000.


So, how much does it cost to build a duplex? Building a duplex can cost anywhere from around $200,000 and $350,000 or more. Duplexes can be a great investment, as they can provide rental income and appreciate in value over time. So if you’re planning on undertaking such a project soon, consider these costs!