Factors that May Determine the Cost of an ADU

Factors that May Determine the Cost of an ADU

ADU prices can vary widely. It is not uncommon to find costs that you may perceive strange, as we have seen basement ADUs that cost $20K and one that was above a garage that cost over $400K. It is difficult to estimate the cost of building an ADU.

The price of construction of the same structure will vary depending on how the builder works and what the current labor costs are in your area. It also depends on the type and size of the structure. A basement ADU is quite different than an ADU located above a garage. These factors make it impossible for us to estimate the average cost of an ADU, and ascertaining these factors is one of the most critical steps in helping you make your decisions when you are wondering how to finance an ADU you are looking to construct.

This makes matters even more complicated. Many homeowners take on sweat equity to cover their out-of-pocket costs, especially in the last stages of construction. This labor contribution can help to defray some out-of-pocket expenses associated with ADU construction.

The floor plan designs, as well as the used materials, have a major impact on the final construction cost. These are the two major factors that can impact the cost of your ADUs. In truth, many factors can impact the cost of your ADU building project. The price of building an ADU will vary depending on the client’s situation. Since the requirements for garage conversions are simpler, ADUs cost more than new ones. You may have to remove the garage and rebuild it if it is in worse condition. Here are the key factors that could have an influence on the cost of ADUs.

Regulation Requirements

The regulations and guidelines of the LA building regulatory body and the construction regulatory board can have an impact on the final construction cost. In order to estimate the cost of construction, you should consider how the regulatory costs will vary depending on the type and size of ADUs that are being constructed.

Engineering Review Cost

ADUs can sometimes be set up in different cities in California with the assistance of an engineer. It is vital to determine if the project will achieve its intended purpose.

ADU construction is a significant decision that requires substantial investments. Price is dependent on many factors. It is possible to reduce the long-term cost by working with qualified people and taking the right steps.


While ADUs are typically smaller than your main residence, it is important that you consider the impact of the design on the construction cost. Talk to an experienced designer to find out how much your plan will cost. The cost of materials for a complex design can be quite expensive. A number of factors affect the design.

ADUs come in three main types: Attached ADUs (or Garage conversion ADUs) and detached new construction ADUs (or both).


Building a 2000-square-foot unit costs more than building a 100-square-foot unit. To calculate the expected cost of ADUs, the builder may provide an estimate by calculating how much it will cost per square foot. However, if you’re setting up large ADUs, your total cost might be lower.

David Mash