Zoning & Size Limits
| Requirement | Los Angeles, CA | San Jose, CA |
|---|
| Allowed Zones | All residential zones (R1, R2, R3, R4, R5, RD, RW, RE, RS, R | All residential zones (R-1, R-2, R-M, R-MH) |
| Max Size (Detached) | 1,200 sq ft | 1,200 sq ft |
| Max Size (Attached) | 1,200 sq ft or 50% of primary dwelling | 1,200 sq ft or 50% of primary dwelling |
| Max Height | Detached: 16 ft base (18 ft within 1/2 mi of trans | 18 ft single-story / 24 ft two-story for a detache |
| Parking Required | No parking required (eliminated statewide by AB 68) | No parking required |
| Owner Occupancy | Not required (CA state law — permanent, no sunset provision) | Not required |
Setback Requirements
| Setback | Los Angeles, CA | San Jose, CA |
|---|
| Rear Setback | 4 ft for units ≤16 ft height | 4 ft |
| Side Setback | 4 ft for units ≤16 ft height | 4 ft |
| Front Setback | Must meet primary dwelling front setback | Per underlying zone |
Permits & Timeline
| Detail | Los Angeles, CA | San Jose, CA |
|---|
| Permit Timeline | 60-day ministerial review (state-mandated) | 60 days |
| Permit Fees | $4,000-$15,000 depending on size and type (plus 10% General Plan Maintenance Surcharge on permit fees as of June 9, 2026) | $4,000-$14,000 |
| Impact Fees | Waived for units under 750 sq ft (state law) | Waived for units under 750 sq ft |
| Pre-Approved Plans | Yes — LA has a Standard Plan Program with pre-appr | Limited pre-approved options available |
Construction Costs
| Cost | Los Angeles, CA | San Jose, CA |
|---|
| Avg Build Cost | $150,000-$350,000 | $180,000-$400,000 |
| Cost Per Sq Ft | $200-$400 | $250-$450 |
| Garage Conversion | $80,000-$180,000 | $100,000-$220,000 |
| Prefab ADU | $100,000-$250,000 | $130,000-$300,000 |
Rental Income Potential
| Rental | Los Angeles, CA | San Jose, CA |
|---|
| 1BR Avg Rent | $1,800-$2,500/mo | $2,000-$2,800/mo |
| 2BR Avg Rent | $2,200-$3,200/mo | $2,500-$3,500/mo |
| Short-Term Rentals | Restricted — STR rules apply; host must be primary resident | Restricted; requires transient occupancy tax registration |
| Est. ROI | 6-10% annual return | 5-9% annual return |
Which City Is Better for ADUs?
Los Angeles scores 9/10 while San Jose scores 8/10 on our ADU-friendliness index.
Los Angeles edges ahead overall. Both cities offer viable ADU development opportunities — the best choice depends on your specific property, budget, and goals.
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