Free Interactive Tool
ADU Rules & Requirements Checker (2026)
Enter your ZIP code or pick a city and see ADU setbacks, height limits, parking, owner-occupancy rules, JADU eligibility, and review type — all up to date with 2026 state and city law.
Check your ADU rules & requirements
Jump to your city
What the checker covers
Every launch city shows the same nine data points so you can compare apples to apples: max ADU size, setbacks, height limit, parking requirement, owner-occupancy rule, JADU eligibility, review type, approval timeline, and short-term rental rules. The values reflect each city's zoning code as of April 2026 and incorporate the latest state ADU preemptions (California AB 68/AB 976, Oregon HB 2001, Colorado HB24-1152).
Once you've checked the rules, cross-sell links route you straight into our permit fee calculator, cost-by-size slider, and each city's full permit guide — so you can move from "what am I allowed to build?" to "how much will it cost?" in a single session.
Frequently Asked Questions
Do I need to live on my property to build an ADU?
Not in California, Oregon, or Colorado. State laws (California AB 68/AB 976, Oregon HB 2001, and Colorado HB24-1152) preempt local owner-occupancy requirements for ADUs. You can rent out both the primary dwelling and the ADU. JADUs (junior ADUs) still require owner-occupancy in California.
Can an ADU be built by-right?
Yes, in the 5 launch cities covered here. By-right (ministerial) approval means your ADU permit cannot be denied based on subjective design review or public hearings if the proposal meets objective zoning and building standards. California requires 60-day ministerial approval under state law; Oregon and Colorado have similar statewide preemptions.
What is a JADU?
A Junior ADU (JADU) is a separately-permitted dwelling unit up to 500 sq ft created entirely within the walls of an existing single-family home in California. JADUs share a bathroom or have an efficiency kitchen and count as a second unit for rental purposes. California lets you add one JADU plus one ADU on the same single-family lot.
What are standard ADU setback requirements?
California state law mandates a minimum 4-foot rear and side setback for ADUs, preempting stricter local rules. Oregon and Colorado typically require 5-foot setbacks. Front setbacks still match the underlying zone. Detached ADUs on corner lots may have additional setback from the secondary street frontage.
How long does ADU approval take?
California statutorily requires cities to approve or deny a complete ADU application within 60 days. In practice, San Diego and LA average 60–90 days; SF averages 75–120 days. Portland typically takes 6–12 weeks for combined zoning plus building review. Denver runs 4–8 weeks.
Do state laws override city zoning for ADUs?
Yes, in California, Oregon, and Colorado. California's ADU statutes (Gov. Code 65852.2) explicitly preempt local requirements that are stricter than state minimums — including parking, setbacks, owner-occupancy, and review type. Oregon HB 2001 and Colorado HB24-1152 establish similar preemptions. Cities cannot impose additional restrictions that conflict with state law.
Can I short-term rent (Airbnb) an ADU?
It depends on the city. California cities (San Diego, LA, SF) broadly prohibit short-term rentals on ADUs — they must be leased for 30+ days. Portland allows STR use but the ADU then pays full System Development Charges (~$12,000–$18,000 extra). Check your specific city rules before assuming STR income.
What counts as a detached vs. attached ADU?
A detached ADU is a standalone structure, physically separate from the main house. An attached ADU shares at least one wall with the primary dwelling (often a converted garage or addition). JADUs are a distinct California category — they must be inside the existing home's footprint.
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