Split use /STR for future 1031 exchange

[RM Jay]

I am in the process of converting our home to STR for 24 months to qualify for a future 1031 exchange. The house is in CA. I also have plans to convert a detached garage to ADU. My plan is to have home on STR with ADU for very limited personal use. This will not be my primary residence. Would IRS consider the ADU part of the main home and limit my use of the ADU for 14 days/10% of rental period to qualify for 1031 Exchange when I sell the house.
Thanks

[Bill B.]

Don’t forget if you sell it as your primary tax free that’s forever. If you do a 1031 California will chase you for the rest of your life to collect their state income tax when you eventually sell. If you’re over the $500k gain, congrats, but you would probably still be better off just renting the home for a year or 2 and exchanging the part over $500k instead of building an du just for that purpose.