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  • Writer's pictureAvo Rino

Cost of ADU in Orange County, California: A Detailed Breakdown

Updated: Mar 30

Here is a detailed breakdown of ADU cost in Orange County, CA:

Constructing an Accessory Dwelling Unit (ADU) in Orange County, CA is an a huge ROI. The all inclusive cost for building an ADU project in Orange County, CA typically ranges between $350 and $550 per square foot. Let’s dive into the details of these expenses:

Design & Engineering Costs: Every ADU starts with a vision, and to bring that vision to life, you'll need some design and engineering expertise. The cost for this expertise can range from $7,000 to $20,000. The exact amount depends on how complex your project is and the architect or designer you choose to work with. Remember, a well-thought-out design can save you money down the road!

Local Fees: These are the fees you'll pay to local governing bodies. They can range from $5,000 to $25,000. This is an inevitable part of your cost of building an ADU in Orange County, CA. Some of these charges depend on the size of your ADU, while others are a set amount. The local city or county can give you a clear breakdown. This includes costs like plan checking, getting the necessary permits, fees for schools, charges from utility companies, fees from the fire department, and other standard city or county charges. A handy tip: If your property is in an unincorporated area, you'll be dealing only with the county's fees. But if it's within city limits, then city fees are what you'll be looking at.

Construction Costs: This is the biggest portion of your ADU cost. It will generally cost between $350 to $450 per square foot. This includes all the foundational work setting up utilities (sewer, water, gas, and electricity lines), and the actual building process – right from laying the foundation, putting up walls, installing the roof, to covering indoor basics like insulation, drywall installation, and giving it a fresh coat of paint.

Finishing Touches: Once the main structure is up, it's time to make it feel like home. This involves choosing cabinets for storage, picking out tiles, deciding on the type of flooring, and other interior details. This is the fun part where you can let your personality shine through!

Your choices, especially in finishes, can greatly affect the overall cost. If you decide to go for more high-end, luxurious finishes, you might find your costs inching past the $550 per square foot mark. But if you choose more standard, yet stylish finishes, you're likely looking at a total between $350 and $500 per square foot.

Where in the range will my project fall?

There are many factors affecting where in this range your project will land. Here are a few examples:

A Sample Rendering for an ADU project in Orange Count, CA by Avorino

Size: Detached ADUs in California are allowed to be up to 1,200 sqft. Building an smaller ADU often cost more per square foot. This is because some costs remain fixed, no matter the size of the project.

Land Prep: The land condition can influence the cost. If it needs a lot of grading or leveling, this can add to the expense.

ADU Location On The Lot: Think about where your ADU will sit on your property. If it's far from main utility lines, it may cost more to connect everything.

Finishes: This is a big one. While everyone loves high-quality finishes, they can push up the budget quite a bit.

Constructing an ADU in Orange County, CA is a significant investment, but it is also an exciting opportunity to add value to your property. As you embark on this journey, there are many details and decisions along the way. Cost of building and ADU in Orange County, CA is one of the many important factors. With Avorino, you're not just getting guidance; you're getting an A-Z experience. Between our company and our trusted partners, we've got you all covered. From the initial planning stages to securing the right permits, from arranging financing for up to 100% of your project, to the actual building phase, and even sourcing the best deals for those perfect finishes – we handle it all.

Dive into your ADU project with the peace of mind that Avorino is with you every step, nail, and tile of the way. We're here to help guide you every step of the way! Let's bring your vision to life, seamlessly.

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