ADU Regulations in Alhambra, California
Los Angeles County · CA · Pop. 85,000
Max ADU Size
1,200
sq ft detached
Rear Setback
4 ft
Permit Timeline
60 days
Build Cost
$155,000 – $315,000
Zoning
Allowed ADU Types
ADUs are permitted in all residential zones consistent with California state law. Multigenerational ADU use is especially common in Alhambra given the large multigenerational household population. JADUs are permitted within the primary dwelling unit only.
Source: City of Alhambra — Community Development Department · Alhambra Municipal Code Chapter 23.16
Dimensions
Size & Setback Requirements
Detached
1,200
sq ft max
JADU
500
sq ft max
Attached
50% of primary home, max 1,200 sq ft
Setbacks
front
Same as primary dwelling
side
4 ft
rear
4 ft
Max height: 16 ft
Lot coverage: Per underlying zone
Alhambra's relatively dense lot patterns in the San Gabriel Valley mean rear-yard space is often limited. Existing nonconforming structures converted to ADUs may use existing setbacks. One-story detached ADUs up to 800 sq ft must be approved regardless of lot coverage or floor-area ratio limits.
Permitting
Permit Process
Department
Community Development Department
Review Timeline
60 days
Permit Fees
$7,500 – $15,000
Impact Fees
Impact fees waived under 750 sq ft
Required Documents
- ›Site plan
- ›Floor plans
- ›Elevations
- ›Title 24 energy compliance
- ›Structural drawings
Alhambra processes ADU permits through the Community Development Department. Given the city's dense urban fabric, applicants should confirm utility connection availability early in the process. Proximity to Cal State LA and the San Gabriel Valley job market supports strong ADU rental demand.
Visit Community Development Department →Infrastructure
Utilities & Requirements
Solar
Required
Parking
Not required
Separate Meter
Optional
Fire Sprinklers
See note
Financials
ADU Costs in Alhambra
Typical Build Cost
$155,000 – $315,000
Cost per Sq Ft
$215 – $280
Monthly Rental
$1,600 – $2,600/mo/mo
Property Value Added
Adds $175,000 – $320,000 to property value
Available Grants & Programs
- ★CalHFA ADU Grant Program available
Alhambra ADUs serve a strong multigenerational housing need and command competitive San Gabriel Valley rents. Build costs reflect the LA County submarket. Many homeowners use ADUs to house family members while offsetting mortgage costs with rental income.
Use the free ADU Cost Calculator →Free Service
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Alhambra Quick Facts
- Max size1,200 sq ft
- Rear setback4 ft
- Permit timeline60 days
- Build cost$155,000 – $315,000
- Rental income$1,600 – $2,600/mo/mo
- Owner occupancyNot required
Official Source
City of Alhambra — Community Development DepartmentAlhambra Municipal Code Chapter 23.16
Last verified: March 14, 2026
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