Each guide answers one question homeowners actually get stuck on, from the statute
itself: quoted verbatim, dated, and linked to the governing section. If a topic cannot be answered from
text we have verified, it does not get a guide.
A California agency has 60 days to act on a complete ADU application, and if it misses the deadline the application is deemed approved under Gov. Code § 66317. Why projects still take months, and what the statute lets you insist on.
A converted garage keeps its existing setbacks (Gov. Code § 66314(a)(7)), the parking it removes never has to be replaced (§ 66314(d)(11)), fire sprinklers are not required unless the house has them (§ 66323(d)), and under 750 sq ft it pays no impact fees (§ 66311.5). The statute, quoted.
A California city cannot deny a permit to an unpermitted ADU built before January 1, 2020 unless it poses a health and safety threat, and cannot charge impact fees or connection charges to legalize it. Gov. Code § 66311.7, which most guides still cite by its dead pre-2026 number, § 66332.
An ADU under 750 sq ft of interior livable space pays zero impact fees in California, and a JADU under 500 sq ft pays none either. Above 750, fees must be proportional to the primary dwelling. Gov. Code § 66311.5(c)(1), quoted, plus what still shows up on the invoice.
Also
Reference pages
Junior ADUs: the 500 sq ft unit that still requires owner-occupancy ·
What SB 543 changed: the 2026 renumbering that broke most citations ·
HCD compliance tracker: which cities' ordinances are actually in force
For your property
Run the numbers for your own lot
The rules above are the statewide floor. What you can build also depends on your jurisdiction's
compliance status and your lot. The feasibility check resolves both and returns a size range with the
governing section for every figure.