City of El Cajon
ADU Regulations in El Cajon.
Everything you need to know about building an ADU in the City of El Cajon. Updated for 2025.
ADU Requirements for El Cajon
The City of El Cajon has its own municipal code governing ADU construction. El Cajon follows state ADU guidelines and has been working to speed up ADU plan review.
Maximum Size
1,200 SF (detached) / 1,000 SF (attached)
Height Limits
24 feet / 16 feet (1-story)
Setback Requirements
4 ft rear and side
Parking Requirements
No additional parking required
Owner Occupancy
Not required
Allowed ADU Types
Detached ADU, Attached ADU, JADU, Garage Conversion
Design Standards
Must meet building code requirements
Fees & Impact Charges
Reduced fees for ADUs under 750 SF
Building in El Cajon?
Our team knows El Cajon inside and out. We'll handle the entire permitting process so you don't have to.
Free Feasibility Check (858) 788-3839Why CRS for El Cajon:
Frequently Asked Questions
How long does it take to build an ADU in El Cajon? expand_more
The typical timeline for an ADU project in El Cajon is 3–6 months for permitting, followed by 3–6 months of construction. Total project timeline from first meeting to move-in is typically 9–18 months.
How much does an ADU cost in El Cajon? expand_more
ADU costs in El Cajon typically range from $150,000 to $350,000+ depending on size, finishes, and site conditions. CRS Builders provides transparent, fixed-price contracts so you know exactly what you'll pay before construction begins.
Can I rent out my ADU in El Cajon? expand_more
Yes. California law prohibits short-term rentals (under 30 days) for ADUs, but long-term rentals are permitted. There is no owner-occupancy requirement, meaning you can rent out both the main home and the ADU.
Do I need a permit to build an ADU? expand_more
Yes, a building permit is required. CRS Builders handles the entire permitting process — from drafting plans to submitting applications and managing corrections. We take the hassle out of permits so you don't have to.