Accessory dwelling units — ADUs — are one of the most practical ways to add housing in Redondo Beach, whether you're building a backyard cottage for a family member, creating rental income, or adding a home office with a kitchen. California state law has made ADUs significantly easier to build over the past several years, and Redondo Beach updated its local ordinance in November 2023 to align with those changes. Here's what you need to know.
What is an ADU?
An accessory dwelling unit is a secondary housing unit on a single-family or multi-family residential lot. It has its own entrance, kitchen, bathroom, and sleeping area — it's a complete, independent living space. ADUs can be attached to your main house (like a converted garage or an addition), detached (a standalone structure in your backyard), or built within existing unused space in a multi-family building.
There's also a smaller version called a Junior ADU (JADU), which is located entirely within an existing single-family home and can be no larger than 500 square feet. JADUs are a good option if you have an underused bedroom or bonus room you want to convert into an independent unit.
What California law allows
State law — starting with AB 68 and SB 13 in 2019, followed by AB 2221 in 2022 and additional updates since — has dramatically streamlined ADU construction across California. The key provisions that apply statewide include ministerial (no discretionary review) approval for qualifying ADUs, a maximum 60-day approval timeline for complete applications, no public hearing required, generally no additional parking required, and reduced setback requirements for detached ADUs (4 feet from side and rear property lines).
Cities can adopt local ADU ordinances that add specifics, but they cannot be more restrictive than state law on key provisions. Redondo Beach adopted its current ordinance — Ordinance No. 3264-23 — on November 7, 2023, updating the previous 2020 ordinance to reflect the latest state requirements.
ADU rules in Redondo Beach
The city allows ADUs on both single-family and multi-family properties, with different rules depending on the type and size. Here are the key standards from the current ordinance:
For ADUs built within existing space on a single-family lot — like a garage conversion — the unit must be located within the existing dwelling or accessory structure, or require no more than a 150-square-foot addition for ingress and egress. This is the simplest path to approval.
For new detached ADUs on single-family lots, the unit can be up to 800 square feet with a height limit of 16 feet (18 feet if your property is near a transit stop). Setbacks are a minimum of 4 feet from side and rear lot lines, consistent with state law.
For multi-family properties, ADUs can be built within existing unused livable space (up to 25% of existing units, with a minimum of one ADU per building), and up to two detached ADUs per lot are allowed. Height limits for detached units on multi-family lots are 16 to 18 feet depending on proximity to transit and building height.
Non-streamlined ADUs — those that don't meet the criteria above — must comply with the development standards for single-family dwellings in the same zone, with exceptions for setbacks and height. Attached ADUs can reach up to 25 feet under certain conditions.
Parking, owner occupancy, and short-term rentals
Three rules that ADU builders frequently ask about: parking is generally not required, owner occupancy is now required, and short-term rentals are prohibited. Under California state law, most ADUs do not trigger additional parking requirements. This is a significant benefit, especially on smaller lots.
As of January 1, 2025, Redondo Beach requires owner occupancy of either the primary dwelling or the ADU on single-family lots. This means the property owner must live in one of the two units. And regardless of occupancy, ADUs in Redondo Beach cannot be rented for stays shorter than 30 days — no Airbnb or vacation rentals.
Junior ADUs: the smaller option
A Junior ADU is built entirely within an existing single-family home and cannot exceed 500 square feet. JADUs must include a cooking facility (which can be a small kitchenette rather than a full kitchen) and a separate entrance. They require a recorded deed restriction, and the property owner must occupy either the JADU or the primary residence. JADUs are a lower-cost way to create a separate unit because they don't involve new construction — you're converting existing interior space.
The permit process
Qualifying ADUs go through a streamlined, ministerial approval process — no public hearing, no discretionary review, and a maximum 60-day turnaround for complete applications. You'll need to submit a building permit application through the Community Development Department, including architectural plans, structural calculations, and Title 24 energy compliance documentation.
The city also references two pieces of state legislation that may help: AB 1332 established a pre-approved ADU plans program (which can reduce design costs if the city offers pre-approved templates), and AB 2234 requires cities to provide an ADU checklist that spells out all requirements upfront so you know exactly what to submit.
Costs include building permit fees, plan check fees, school fees, and utility connection fees. These vary based on the size and type of your project. For an estimate, contact Building & Safety at (310) 318-0636 or check the city's Master Fee Schedule on redondo.org.
Getting started
The best first step is to contact the Community Development Department and confirm what's allowed on your specific property. The Planning Division can verify your zoning, lot size, and any restrictions that might apply. The Building & Safety Division handles the actual permit application.
Planning Division: (310) 318-0637, PlanningRedondo@redondo.org. Building & Safety: (310) 318-0636, BuildingRedondo@redondo.org. Counter hours are Monday through Thursday, 7:30 AM to 1:00 PM, and alternating Fridays. Both offices are at 415 Diamond Street. The city's ADU resource page on redondo.org has links to the current ordinance, the state ADU handbook, and application materials.