Zoning & Size Limits
| Requirement | San Diego, CA | Berkeley, CA |
|---|
| Allowed Zones | All residential zones; also allowed in some commercial mixed | Any lot zoned to allow residential use with an existing or p |
| Max Size (Detached) | 1,200 sq ft | 1,200 sq ft outside the Hillside Overlay; 850 sq ft (studio/1-bedroom) or 1,000 sq ft (2+ bedrooms) within the Hillside Overlay |
| Max Size (Attached) | 1,200 sq ft or 50% of primary dwelling | Same limits as detached (1,200 sq ft outside Hillside Overlay); conversions of existing space have no size cap |
| Max Height | 25 ft (2 stories) | Detached new construction: 25 ft (20 ft within Hil |
| Parking Required | No parking required | None required for ADUs or JADUs; displaced garage parking do |
| Owner Occupancy | Not required | Not required for ADUs. JADUs with separate sanitation facili |
Setback Requirements
| Setback | San Diego, CA | Berkeley, CA |
|---|
| Rear Setback | 4 ft | 4 ft minimum |
| Side Setback | 4 ft | 4 ft minimum (interior or street side); architectural features may project 2 ft if 2 ft remains to the property line |
| Front Setback | Per underlying zone | ADUs may be placed within the front setback |
Permits & Timeline
| Detail | San Diego, CA | Berkeley, CA |
|---|
| Permit Timeline | 60 days (often faster) | 60-day ministerial review; deemed approved if the city fails to act within 60 days (SB 543, eff. Jan 1, 2026) |
| Permit Fees | $3,500-$12,000 | $250 zoning plan check + $500 neighbor noticing fee at submittal + $250 address assignment; building permit fees based on project valuation (city fee estimator tool available) |
| Impact Fees | Waived for units under 750 sq ft | Land Use Planning assesses no impact fees. Berkeley Unified |
| Pre-Approved Plans | Yes — companion unit program with pre-approved des | Yes — the city points applicants to pre-approved A |
Construction Costs
| Cost | San Diego, CA | Berkeley, CA |
|---|
| Avg Build Cost | $120,000-$300,000 | $250,000-$500,000 |
| Cost Per Sq Ft | $180-$350 | $400-$700 |
| Garage Conversion | $70,000-$160,000 | $120,000-$250,000 |
| Prefab ADU | $90,000-$220,000 | $250,000-$320,000 |
Rental Income Potential
| Rental | San Diego, CA | Berkeley, CA |
|---|
| 1BR Avg Rent | $1,600-$2,200/mo | $2,300-$2,900/mo |
| 2BR Avg Rent | $2,000-$2,800/mo | $3,000-$3,900/mo |
| Short-Term Rentals | Allowed with STRO license in certain zones | No — recorded deed restriction prohibits short-term rental o |
| Est. ROI | 7-11% annual return | 4-7% annual return |
Which City Is Better for ADUs?
San Diego scores 9/10 while Berkeley scores 9/10 on our ADU-friendliness index.
Both cities offer viable ADU development opportunities — the best choice depends on your specific property, budget, and goals.
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