How Long Does It Take To Build an ADU From Start To Finish?

How long does it take to build an accessory dwelling unit, or ADU? When you rely on a trusted general contractor in Morgan Hill, CA, expect the project to take at least six months. However, several factors can affect the timeline, potentially lengthening it to a year or longer.

Learn more about the ADU construction timeline and what factors may influence it.

Planning and Designing Your ADU

Although many people start by focusing on the ADU permit and construction schedule, creating the design is an important first step. The timeline for planning and designing can range from a few weeks to several months. 

Property owners in a hurry to start the ADU process may consider a basic design that allows construction to start faster. Other people may want to include customizations that significantly lengthen the timeline.

When you work with a local contractor, you’ll have access to designers and architects who can work with you to develop the appropriate plans. Homeowners can have as much or as little involvement in this phase as they want.

Obtaining Permits and Approvals

How long does it take to build an ADU if you need to obtain permits and approvals? The permitting process can take anywhere from a few days to several months, depending on your location. Predicting the ADU building process duration related to permits is one of the most challenging aspects of doing this work.

Your ADU’s exterior design might need to adhere to a certain look or match the style of the main home. If the build site lacks access to electrical or plumbing lines, you’ll need permits to extend these lines across the property. 

You may also need to follow the rules of a homeowners’ association (HOA) for your ADU, limiting where you can build and how large it can be. It’s important to understand these local rules before starting the design to avoid potential setbacks that can lengthen the timeline.

Constructing the ADU

How long does it take to build an ADU after obtaining the permits? Construction usually requires around six months, although it can take 12 months or longer.

Units with more square footage will take longer to build than smaller units. If you’re building a multi-story facility with a basement, this will require more time than a single-story unit that’s on a concrete slab. 

Pouring the foundation and adding the plumbing and electrical rough-ins can take four to eight weeks, while framing and adding insulation and drywall may add another two to six weeks. 

The contractor will add the interior and exterior finishes to the ADU as the final steps. This can add another four to six weeks to the process.

The local building inspector needs to sign off on the process at each stage, ensuring the construction is safe. Delays during inspections can lengthen the timeline. You cannot begin occupying the ADU until the inspector closes the permits after the final inspection.

As the property owner, you will conduct a final walkthrough with the contractor after everything is finished. If you find problems, repairs might need a few more weeks.

Other Issues That Can Lengthen the ADU Timeline

How long does it take to build an ADU if some unexpected situations arise? Predicting the time required to build a detached ADU can be challenging in this scenario.

Although Morgan Hill, CA, has a pleasant climate and minimal rainfall, changes in the weather can sometimes get in the way. If construction is occurring during the winter months, the chances of cold weather and precipitation could affect the building process.

If you want to use specialty materials for the construction, you might experience delays in ordering and obtaining them. Experienced contractors can work around these issues to try to keep the project moving forward as efficiently as possible.

Count on Michael Marini Construction for an Accurate ADU Construction Timeline

How long does it take to build an ADU, and what factors should you consider to speed up the process? One factor that significantly affects the ADU construction timeline is the contractor you select for the work. 

At Michael Marini Construction, we have more than 20 years of experience helping California homeowners with their building projects. We can assist with the ADU design, discuss the property tax implications you’ll face, and provide guidance on everything in between.

To talk about your ideas, contact us today at (408) 310-8732. We’ll deliver the project of your dreams within a timeframe you can trust.