Converting a garage to an ADU in Long Beach

Can you use the city's conversion application?

Long Beach's Building and Safety Bureau has an "Accessory Dwelling Unit Garage Conversion Application" that lets an owner draw the site plan and floor plan on the form's own pages. It's the simplest route, and it is narrow. To qualify, the project must:

• be created solely from the existing floor area of a single-story garage in a single-family zone, with no added floor area or footprint¹
• not be in the coastal zone or a historic district¹
• not be in zones R-M, R-4-M, RP or PUD¹
• have utility sizes that are adequate for the ADU and verified before the permit is issued¹

There's also a paperwork step that surprises people. You submit your grant deed, city staff prepare a covenant, and that covenant has to be recorded before the permit is issued.¹

If your garage fails any of these tests, you aren't barred from converting it. You are on the standard plan review route, which needs a complete set of construction documents including an energy report.²

What the drawings have to show

Some of the items on the application's site plan and floor plan lists are easy to miss:

• the distance to the nearest public fire hydrant¹
• any electrical subpanel, with justification that the existing panel can carry it¹
• U-factor and SHGC values for the windows¹

Do you need an architect or engineer?

Not always. The Bureau's FAQ says plans signed by a registered design professional are not required for a garage conversion where the work fully complies with IB-010, the city's bulletin on prescriptive wood-frame construction.² Step outside those prescriptive provisions and you will need one.

Setbacks: the building code can ask for more

This is the Long Beach point most likely to affect a new detached ADU. Planning staff apply zoning setbacks; building staff apply fire separation distances; and the ADU has to meet whichever is more restrictive.² Fire separation runs from 0 to 5 feet depending on wall construction, openings and sprinklers.² The city's example is a four-foot zoning setback against a five-foot fire separation, where the ADU ends up five feet from the property line.²

The distance between the ADU and the main house is worked out the same way, by adding together the separation each building needs.² On a tight lot, wall rating and window placement on the facing sides can decide whether a design fits.

Submitting

The FAQ describes in-person submittal at the Permit Center with fees paid the same day², documents as PDF files on a USB device², and appointments recommended.² The conversion application goes further and says an appointment must be made.¹ The FAQ was last revised in August 2024², and the conversion application carries no single revision date, with one of its attached forms dated August 2021.¹ Both predate the 2026 state changes, so confirm the current submittal method with the Permit Center before you go.

With one existing single-family home on the lot, a single set of documents and one combination building permit application covers the building, electrical, mechanical and plumbing work.² Ask for the ADU's address at the same time using form APP-015.²

A property owner, a California-licensed contractor or an authorized agent can pull the permit.²

Utilities and sprinklers

You have to decide whether the ADU will share the main house's utility services or have its own meters, because different requirements can follow from that choice.²

A garage conversion needs fire sprinklers only where the existing house has them or is required to.² If they are needed, the sprinkler work has its own fire application, plan review and permit.²

The pre-approved plan route

Long Beach calls its pre-approved designs PAADUs. They are for new units on single-family zoned properties.² The plans belong to the design professionals who drew them and are available only from those professionals.² In return for accepting the design largely as drawn², the project is eligible for over-the-counter minor plan review.²