Build Duplex Costs

Duplex construction is far more like single-family home construction than it is like building apartments or condos. Most duplexes are single or two-story structures that may have already been a single-family home. Duplexes are also typically larger, with the average duplex in the U.S. around 900 square feet. In the case of a four-unit building that requires 4,000 square feet of construction, there are a lot of factors involved in determining the cost.

This type of building is never going to be on the lower end of the estimate ranges. Because it is essentially building multiple “homes” at once, it takes a lot of time, money, and materials to get the job done right. Usually, construction costs average around $126 per hour for the total job (including labor and materials). The number of units in the building, whether it is new construction, and what type of materials you use will also affect the cost of this construction project.;

Because a house or multi-unit family construction project is priced on a larger scale, it can be hard to get an idea of exactly what you are paying for. You will also need to invest in an architect to draft a building design, a list of work, a budget, and drawings. They will also administer the process of construction and make sure that final details are taken care of. Most architects charge 10-17% of the total budget.

Duplex construction: 4,000 square foot building with four units.

Other considerations and costs

• Building permits will be required for this project. On average, they cost around $450. Check with your contractor to find out what you need.
• Remember that you have to factor in any land clearing, demolition, or site preparation. Depending on where you are building, this could be as little as $100 for materials or it could be as high as $20,000.
• The cost estimates do not include furnishing the units. Expect to spend another $500-$25,000 on furniture and other furnishings.
• Check out our guide if you need a loan for your home improvement project
• If you are a builder and need insurance check out our Builders Risk Insurance Guide

DIY considerations

• New construction is not for the DIY weekend. Especially with a duplex or other multi-unit property, you need trained professionals for all aspects of the work.
• You can cut labor costs a little by helping with loading and unloading, removal of old materials (if any).

References

• Craftsman Estimator Costbook, complete series year 2019.
• Latest prices found on Home Depot and other vendor Web sites.
• Literature review of DIY Web sites.