considering adding ADU's - will this affect my current loan?

[David Isham]

I live in a 3 unit building and I have discovered it is possible to add two ADUs (Accessory Dwelling Units) to my property in California. I currently have a $1MM loan @ 2.25% fixed for 30 years so this is a keeper for a lifetime of a loan. If I add 2 additional ADU's my understanding is that this moves the property into a commercial 5 unit classification. What would that do to my existing loan if I did add 2 ADUs? And what if I just added 1 ADU to bring it up to only 4 units? Does my existing lender care that I added these 2 units? I would finance these units myself (about $400k each) so no loan required and I don't plan to ever refi. Each ADU would bring in at least $5k per month if I did Airbnb so it would be a big win for me. I don't want to mess with my existing loan however so I am not sure how to move forward.