What is an ADU and how do you build one?

I did an ADU project a couple of years ago. The project took about 9 months from planning to completion. It was worth the effort and I was very pleased with the outcome. So....what's an ADU?

An Accessory Dwelling Unit (ADU) is a smaller, independent residential unit located on the same lot as a primary home. These can be:

• Detached (a separate structure)

• Attached (connected to the main home)

• Converted spaces (like garages or basements)

• Junior ADUs (JADUs): up to 500 sq ft, located entirely within the main home

Each city/county has different programs and restrictions so make sure to check with your local jurisdiction. Some common considerations might include lot size, building size, set backs, heigh restrictions, water restrictions, separate access, occupancy requirements, and kitchen and sanitation requirements.

Here are Monterey County’s ADU Program Highlights:

• Pre-Designed Plans: The county offers three free, pre-approved ADU designs (1-, 2-, and 3-bedroom) in two architectural styles—Santa Lucia Modern and Ventana Ranch. These streamline the approval process and save homeowners $1,000–$3,000 in design costs.

• Permit and Build Process:

  1. Review ADU regulations (Inland or Coastal zones

  2. Review water rights and restrictions to ensure you have water credits. Do you have enough credits to add sinks and bathroom? Do you need to buy water? If your property uses a septic system or private water source, additional review by the Environmental Health Bureau may be required.

  3. Hire a designer or architect to site the ADU

  4. Hire a licensed contractor

  5. Submit plans to the Housing & Community Development Permit Center

  6. Undergo inspections during construction

  7. Finalize and move in!

     
     

Why Build an ADU?

• Affordable housing for family, caregivers, or renters

• Rental income potential (but no short-term rentals allowed)

• Increased property value

• Sustainable infill development—no need to consume more land
  

If you’re considering adding an ADU to a property in Monterey, may sure to do your research and get permits! Although it may take some time and money, doing it the right way will make selling your home a lot easier!

Source: CountyofMonterey.gov