Buying Home with Un Permitted ADU

[Kristjan Schweizer]

Hey there!

I am considering purchasing a home that has a fully built ADU. I am considering the risk and was hoping for some input. The ADU was built by a licensed and bonded contractor that didn't get the permits due to time constraints. I plan on living in the home and renting out the ADU. I am not sure I even need to permit it but curious of risks I am taking on and if anyone here has experience with this type of situation.

[Whitney Hill]

Chiming in with my two cents on what process & cost would look like for permitting a previously unpermitted ADU in San Diego.

Similar to bringing an illegal addition into compliance, it would require drawing a plan for the existing ADU (typically $2-3K), sending it to plan check at the city (planning, building, and fire), potentially conducting an exploratory phase where walls are opened up for inspection with the city (typically no more than $1-2K for opening walls and repairing them), addressing anything in the structure that is not within compliance (cost will of course depend on what's going on with your structure), and paying for any permits (typically $1K). Best-case timeline might be 3-4 weeks, typical more like 8-10 weeks, and of course upwards from there if the city is backed up and/or you find issues. Hope this helps!