10/29/2026
Permits are the part of an ADU project most homeowners dread. Here's why they don't have to be scary. 📋🏡
Every legal ADU in California needs a building permit, and that's a good thing. A permitted unit can be rented legally, insured properly, and counted when you sell or refinance. The good news is that state law has made the process far more predictable than it used to be.
Here's how it generally works:
1️⃣ Feasibility check
Before any drawings, your team reviews your lot: zoning, setbacks, easements, utility locations, and any special conditions like a hillside or fire zone.
2️⃣ Design and plans
An architect or designer prepares a full plan set, typically a site plan, floor plans, elevations, structural details, and energy (Title 24) compliance.
3️⃣ Submit and review
Your city or county reviews the plans. Under California law, a complete ADU application must be approved or denied within 60 days, and ADUs that meet the state standards are approved administratively, without a public hearing.
4️⃣ Corrections
It's common to get a round of plan check comments. A good team responds quickly so your project keeps moving.
5️⃣ Permit issued, then inspections
Once approved, construction begins, with city inspections at key stages until final sign-off.
⚠️ Common mistakes: building first and permitting later, submitting incomplete plans that restart the clock, or assuming every city has the same rules. State law sets the baseline, but local details like fees, utility requirements, and submittal checklists vary.
💡 Tip: Ask whether your city offers pre-approved ADU plans. Some Southern California jurisdictions do, and they can simplify plan review.
At The ADU Pro, we handle design, permits, and construction under one roof, so you don't have to chase paperwork.
Ready to get your ADU approved? Contact us for a free estimate!
📞 (877) 398-8002
🌐 theADUpro.com
