ADU guides · Updated October 2026

San Diego ADU guides, written as straight answers.

Each guide answers one question in the first paragraph, then covers the detail and the cases where it depends. Every figure and rule carries a date.

Cost and income

How much does an ADU cost in San Diego?Published ranges by ADU type, add-on costs and San Diego fees.Read the guide How much rent can an ADU make in San Diego?Current San Diego rents by unit size and the rental rules that apply.Read the guide

Rules and permits

What are the ADU rules in San Diego in 2026?State law, the Bonus ADU reforms, separate sale and short-term rentals.Read the guide Do I need a permit to build an ADU in San Diego?Which office issues it, review deadlines and the coastal zone.Read the guide

Planning your project

Should I convert my garage or build a new ADU in San Diego?Price, size limits, placement and the garage details that tip the decision.Read the guide How long does it take to build an ADU in San Diego?Phases, state review limits and what slows San Diego projects.Read the guide

Want the answer for your own lot?

Tell us where the property is and what you have in mind. We read the zoning and ADU rules for that address, then reply with what could fit. Serving San Diego, Chula Vista, La Mesa, El Cajon and Escondido.