Sunnyvale, CA Accessory Structures: ADU Rental Restrictions (2026)

Section 19.79.040(r) states plainly that an accessory dwelling unit approved on or after January 1, 2020 shall not be used as a short-term rental as regulated by Chapter 19.76. This mirrors and reinforces Section 19.76.040(a)(5), which draws the same line: ADUs approved on or after January 1, 2020 cannot host short-term rentals, but an ADU approved before that date may still be used as a short-term rental if the host resides on the lot containing the unit. Any dwelling unit created under Chapter 19.78 (dual urban opportunity units built on an urban lot split) is barred from short-term rental use outright, with no pre-2020 exception.

The restriction attaches to the ADU's approval date, not to the household's living arrangement, so a homeowner who otherwise satisfies the host-presence and primary-residence rules in Chapter 19.76 still cannot legally book short-term guests in a post-2020 ADU. The rule is meant to preserve newly created ADUs as long-term housing stock rather than allow them to be absorbed into the short-term rental market as soon as they are permitted.