Everything homeowners ask about building an ADU in Glendale — answered with 2026 data.
Yes, ADUs are allowed in Residential zones permitting single-family or multifamily use, on lots with an existing or proposed dwelling (GMC 30.34.080) in Glendale, CA. The maximum size for a detached ADU is 850 sq ft for a 1-bedroom ADU; 1,000 sq ft for a 2-bedroom ADU, regardless of underlying zoning standards (units over 850 sq ft must add a second bedroom). Attached ADUs can be up to 850-1,000 sq ft caps apply; confirm attached-specific limits (50%-of-primary state rule) with Glendale Planning Division. Glendale has an ADU-friendliness score of 6/10. Check our full Glendale ADU rules page for complete zoning details.
ADU construction in Glendale typically costs $180,000-$400,000. The cost per square foot averages $300-$500. Garage conversions are more affordable at $100,000-$200,000, while prefab ADUs cost $180,000-$300,000. Permit fees add Approximately $6,000-$18,000 total (plan check, building permit, school fees, utility connections — builder estimates); Glendale Water & Power connection fees add roughly $2,000-$5,000 for new services. Confirm with the Building Division, (818) 548-3200 to your budget. See our detailed Glendale ADU cost guide.
Detached ADUs in Glendale can be up to 850 sq ft for a 1-bedroom ADU; 1,000 sq ft for a 2-bedroom ADU, regardless of underlying zoning standards (units over 850 sq ft must add a second bedroom). Attached ADUs are limited to 850-1,000 sq ft caps apply; confirm attached-specific limits (50%-of-primary state rule) with Glendale Planning Division. Junior ADUs (JADUs) have a cap of 500 sq ft. Maximum height is Detached and attached ADUs: 1 story, max 16 ft; 18 ft allowed within 1/2 mile of a major transit stop or high-quality transit corridor (or where existing development is multi-story), +2 ft to match the primary dwelling's roof pitch. Local ban on ADUs above detached garages is not being enforced pending HCD-required amendments. You are allowed up to Single-family lots: 1 ADU + 1 JADU. Multifamily lots: state-law unit counts apply (conversion ADUs up to 25% of units plus detached ADUs; SB 1211 allows up to 8 detached) — Glendale's more restrictive unit-mix interpretation is paused under the HCD settlement on a qualifying lot.
Rear setback: 4 ft maximum required for detached new-construction ADUs; none for conversions of existing structures. Side setback: 4 ft maximum required for detached new-construction ADUs; none for conversions. Front setback: Underlying zone front setback applies; confirm exceptions with Glendale Planning Division. Note that garage conversions may be exempt from setback requirements if the existing structure is already within the setback area.
1 space required unless exempt per GMC 30.34.080(H)(4) — exemptions include locations within 1/2 mile of transit and conversions; no replacement parking for converted garages. Many cities and states have been relaxing ADU parking requirements in recent years. In California, no additional parking is required for ADUs near transit.
Not required for ADUs. JADU owner-occupancy removed by AB 1154 (eff. Jan 1, 2026) for JADUs with separate sanitation facilities. Note that owner-occupancy rules vary by state law — California and several other states have eliminated this requirement for standard ADUs.
The ADU permit review timeline in Glendale is typically 60-day ministerial review; deemed approved if the city fails to act within 60 days (SB 543, eff. Jan 1, 2026). Plan check: Included in valuation-based permit fees; expedited review available for pre-approved standard plans. Pre-approved plans availability: Yes — Glendale's Standard ADU Plan Program (Pre-Approved ADU Program) offers expedited review using plans designed and owned by listed firms (e.g., a 1-story 740 sq ft 1-bed/1-bath plan); plans are purchased directly from the designers.
Average ADU rental income in Glendale: 1-bedroom units rent for $2,000-$2,700/month, 2-bedroom units for $2,800-$3,400/month. Short-term rentals: No — short-term rentals under 30 days are not permitted for ADUs in Glendale. Expected ROI: 5-8% annual return.
The minimum lot size for an ADU in Glendale is None for state-mandated ADU pathways. This applies to detached ADUs — garage conversions and JADUs may have different or no lot size requirements.
Garage conversions are one of the most popular and affordable ADU options. In Glendale, a garage conversion typically costs $100,000-$200,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.