Monterey County ADU Resource Guide

Ready to start planning your ADU? Here are some local resources that can help.


If you’re located on the peninsula, water availability may be a challenge. The cities of Seaside and Pacific Grove currently do have water credits available for purchase. Several areas of the Peninsula have water availability issues. However, it may still be possible that you have water credits available or existing water credits to accommodate certain planned ADUs. Click here for a form from the Monterey Peninsula Water Management District (MPWMD) which can help to calculate the amount of water that is needed for your ADU or find other useful forms on MPWMD’s website. Learn more about the Pacific Grove Water Purchase wait list. For more information on how to move around water credits in your home, read this guide and look at this list of rules from the MPWMD. Contact the Monterey Peninsula Water Management District for more questions at (831) 658-5601.


If you live in unincorporated North County areas, you may have issues with water quality that could stand in the way of constructing an ADU. To find out more, contact the county at (831) 755-5025.


One of the biggest barriers for most homeowners is financing their ADU. There are currently no ADU specific loan products available in Monterey County. However, conventional financing options may be an option for you to finance your ADU.


The City of Seaside has developed pre-approved plans for Seaside homeowners to use. Other homeowners in the county are welcome to use the plans to save cost on designing a detached ADU. Keep in mind that they are not plan check pre-approved except within the boundaries of the City of Seaside.


There are several local architects who are knowledgeable about ADU design and can adapt plans or design new plans for you. Please contact Kelly deWolfe, Impact Associate for Affordable Housing at for more information. 


United Way of Monterey County, with the help of our partners, has created a list of local building companies creating prefabricated ADUs. Building your ADU prefabricated can save on construction costs.


Some restrictions may still apply to your property; however, many local limits have been eliminated as of January 1, 2020. Learn more about the local city code for your area and the 2020 state law information.


For clarity on any of the above information, or for additional questions, contact Kelly deWolfe at


If you’re interested in building an ADU in Monterey County, we want to hear from you! Take our survey for interested homeowners.