If you are thinking of building a duplex as a way of creating quality equity, then you are definitely on the right path. Why is this so? Well, unlike condos or an apartment building, duplexes offer you an opportunity to fully maximise your profits or returns. One of the things that help maximise profits is avoiding unnecessary building costs as well as unnecessary fee permits. Other than profits, you are more likely to build a duplex within pre-existing structures.

With all the positives associated with duplexes, many are keen on building one themselves. This, in turn, has led to an increase in the number of people interested in matters duplexes. In particular, many want to know how they can be able to build a duplex without breaking the bank. It is with this that we’ve opted to share with you this post on how much it costs to build a duplex. Before this, however, let’s get to focus on or look at what a duplex really is.

What Is A Duplex?

In terms of definition, a duplex or dual occupancy is a single residential building that has two dwellings under one roof. In most cases, there is a concrete wall built to help separate the two. Despite them sharing a roof, duplexes tend to have their own entries, yard and amenities. These types of residential buildings are a hit with many investors given its value once complete. Once you build a duplex, you will be in a position to collect two rental incomes from one property.

Even better, the selling return in most cases is also above average. Of importance to note if you thinking of selling a duplex is that they can be on one title. If you are an investor with both properties on one title, you’ll have to sell both of them. If they are in different titles, you have the option of selling only one.

How Much Does It Cost To Build A Duplex?

So how much does it cost to build a duplex? Well, to best answer this question it is important you understand what’s and who is involved in building a duplex. Before going any further, we would like to point out that different duplex developments require different materials and expertise. What this does is impact the cost to build a duplex. Therefore, the figures in this post are estimations. To get a clear picture of cost to build a duplex, we highly recommend speaking directly with an expert.

That out of the way below is a list of things that’ll definitely impact the cost of building a duplex;

  • Architects & Contractors
  • Location
  • Materials

Architects & Contractors

The process of building a duplex is not your ordinary “DYI” project. To get the very best, you’ll require the services of an expert or professional to help you see things through. In other words, you’ll need the services of an architect or a contractor. With this, you’ll have to pay for the services they offer. The fees architects or contractors charge roughly total up to 10 – 17% of the total budget of building a duplex. In terms of price, figures show that an architect working on a duplex project receives between $55,100 and $93,800. Contractors, on the other hand, receive roughly $79,100 in mark-up and indirect fees.

What will an architect do for you?

  • Determine the scope of your duplex development and help establish a preliminary budget
  • Help you create a schematic design as well as draft floor plans with detail elevation drawings
  • Outline preliminary plans, draft a list of work to be done and budget
  • Complete all necessary construction documents
  • Give relevant and much-needed advice during the entire project
  • Review plans with local agencies that have been set up as well as obtain all relevant permits
  • Incorporate details about materials that’ll be used during development
  • Make sure that payment requests by contractors are accurate

What will a contractor do for you?

  • Provide all materials and services you’ll require for building a duplex
  • Assist with hiring subcontractors when needed
  • Suggest ideas and plans to project developers that’ll help meet project goals
  • Help with accessing utility installation and work permits


Location or where you choose to build a duplex is very important when answering how much it cost to build a duplex. You want to make sure you go for a good spot on the map for your prime duplex development. When settling on a location, top on your mind should be searching for things that’ll make for a perfect investment. This includes going for a location that is close to major employment hubs or cities. It should also be in a place where there is good infrastructure, nice population growth, and high rental demand. Other necessities like shopping centres, schools and entertainment facilities should also be factored in.

The problem with getting a plot in such an area is that you’ll most likely pay up top dollar for it. This in mind, the question is how you can get such a location without having to spend too much. The trick here is looking for flat blocks in such areas. This’ll help you keep costs down significantly. It’s not just flat blocks make sure you focus on the zoning of your plot. This also includes plans of future rezoning in the city if any.


The materials you use also factor in when looking at the total cost of building a duplex. In most cases, a duplex built with mid-range materials on a normal foundation with features like a full finished basement, windows, appliances, a turnkey finishing structure as well as efficient doors will end up costing you between $120,000 and $200,000 per unit. With this estimate, the assumption is that those involved in the development process have certain pricing.

For instance, the assumption is carpenters charge, masons and excavators charge an average of $85 and $125. Electricians, plumbers and painters both take $65 to $85 per hour, $45 and $65 per hour and $20 and $35 per hour respectively. This in mind, it important you settle with just the right materials for your duplex. Furthermore, you ensure that their price matches or is in line with your budget.

If you have additional queries or inquiries on how much it cost to build a duplex, do contact Duplex Invest over the phone using 0410 314 179 for unmatched expert advice and assistance.