ADU rules in Pasadena
The key facts first, then what we've learned building there.
The snapshot
Checked October 2026. We re-check every lot against the current code.
Pasadena
| Rule | Answer |
|---|---|
| Detached ADU size | Up to 1,200 sq ft |
| Setbacks | 4 ft side and rear |
| Height | 16 ft; 18 ft near transit; 25 ft attached |
| Historic districts | Units visible from the street in landmark and historic districts are limited to 16 ft |
| Pre-approved plans | Yes: "Prototype A", a 374 sq ft studio, free citywide. The older standard plans expired December 31, 2025 |
| Changes to a pre-approved plan | Not allowed: any change means a full plan review with standard fees |
| Pre-approved plan check | About 3 to 4 weeks |
| Eaton Fire lots | Extra pre-approved plans (about 400 to 750 sq ft) for red-tagged lots only |
| SB 1211 apartment ADUs | Yes |
| Utilities | Pasadena Water & Power |
| Building department | Pasadena Planning & Community Development |
What's different here
In landmark and historic districts, an ADU visible from the street is capped at 16 ft. We place and shape it to fit before design starts.
Pasadena's pre-approved plans must be built as drawn; moving even a window means a full plan review. We help you decide between a free plan and a custom one.
For red-tagged lots, the city lists extra pre-approved plans of about 400 to 750 sq ft. We match the plan to the lot and the rebuild.
Pasadena runs its own utility, with its own process for service and panel upgrades. We request it early so it doesn't hold up the permit.
Pasadena has its own tree ordinance. We map protected trees before placing the ADU.
What applies here
Rebuild after a fire, with an ADU to live in or rent while the main house goes up.
Learn moreCities must now keep a set of pre-approved ADU plans.
Learn moreSince January 2025, California lets an existing apartment property add detached ADUs, one for every existing unit up to eight, plus conversions of garages and storage.
Learn moreSB 9 lets a single-family lot be split in two, with up to two homes on each.
Learn morePlans that fit
Ready-drawn plans we adapt to your lot and your city.
Ask about your address
We check the lot against these rules and tell you what fits.



