Structure Height Limits: Altadena vs South San Gabriel
How do structure height limits rules compare between Altadena, CA and South San Gabriel, CA?
Altadena and South San Gabriel have similar restriction levels.
Altadena, CA
Los Angeles County
Altadena R-1 max height: 35 ft on lots ≥20,000 sf; 30 ft on lots <20,000 sf and flag lots. Maximum 2 stories above grade. No portion of any structure may exceed 23 ft if within 15 ft of any property line.
View full Altadena rules →South San Gabriel, CA
Los Angeles County
Building height limits in unincorporated LA County are set by Title 22 zoning district. Height limit exceptions exist for elevator shafts, stairwells, and similar features per Section 22.110.060.C. Community Standards Districts may impose stricter height requirements.
View full South San Gabriel rules →Key Facts Comparison
| Fact | Altadena | South San Gabriel |
|---|---|---|
| Code Section | Altadena CSD 22.306.070.A.2 | - |
| Max Height ≥20k sf | 35 ft | - |
| Max Height <20k sf | 30 ft | - |
| Flag Lots | 30 ft | - |
| Max Stories | 2 above grade | - |
| Within 15 ft of PL | 23 ft | - |
| Varies By | - | Zone and Community Standards District |
| Exceptions | - | Elevator shafts, stairwells exempt |
| ADU Detached | - | 16 ft per state law |
| Reference | - | Title 22, Section 22.110 |
Highlighted rows indicate differences between cities.
Altadena FAQ
How tall can a house be in Altadena?
35 ft on lots 20,000 sq ft and larger, 30 ft on smaller lots, with a maximum of 2 stories above grade (Altadena CSD 22.306.070.A.2).
South San Gabriel FAQ
How tall can I build in unincorporated LA County?
In most R-1 residential zones, the limit is 35 feet or 2.5 stories, whichever is less. Height limits vary by zone. Check your zoning district in Title 22 or at planning.lacounty.gov.
How is building height measured?
Height is measured from the lowest point of the natural or finished grade (whichever is lower) to the highest point of the roof, including ridges and equipment.
Can I get a height exception?
Yes, through a Conditional Use Permit or variance from the Regional Planning Commission. This requires a public hearing and demonstration that the exception is justified. Contact (213) 974-6411.
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