Light Trespass: San Mateo vs South San Francisco
How do light trespass rules compare between San Mateo, CA and South San Francisco, CA?
San Mateo has fewer restrictions than South San Francisco.
San Mateo, CA
San Mateo County
San Mateo addresses light trespass through zoning development standards and nuisance provisions. New development must shield exterior lighting. Existing light trespass complaints are handled by Code Enforcement on a case-by-case basis.
View full San Mateo rules →South San Francisco, CA
San Mateo County
Unincorporated San Mateo County's Development Code requires exterior and interior lighting to be designed and located so that direct rays and glare are confined to the premises. The performance standards state no direct or reflected glare shall be visible, though reasonable shielded security lighting is allowed.
View full South San Francisco rules →Key Facts Comparison
| Fact | San Mateo | South San Francisco |
|---|---|---|
| Regulation | Nuisance-based enforcement | - |
| New Development | Shielded lighting required | - |
| Security Lights | Aim to avoid neighbor impact | - |
| Enforcement | Code Enforcement — 650-522-7200 | Planning and Building code enforcement |
| Standard | No specific lux/footcandle limit | - |
| Governing Code | - | Development Code (Title 8) |
| Core Standard | - | Direct rays/glare confined to premises |
| Glare Standard | - | No direct or reflected glare visible |
| Security Lighting | - | Allowed if properly shielded |
| Permit Condition | - | Glare contained to subject parcel |
Highlighted rows indicate differences between cities.
San Mateo FAQ
My neighbor's light shines into my bedroom. What can I do?
File a complaint with Code Enforcement at 650-522-7200. Light trespass creating a nuisance can be addressed, and the city may require the neighbor to modify their lighting.
Are there specific brightness limits?
No. San Mateo does not have specific lux or footcandle limits for light trespass. Enforcement is based on whether the lighting creates an unreasonable nuisance.
South San Francisco FAQ
What can I do about a neighbor's light shining on my property in unincorporated San Mateo County?
County Development Code standards require exterior and interior lighting to be designed so direct rays and glare are confined to the premises. If a permit lighting condition is violated, Planning and Building code enforcement can require shielding or correction.
Is security lighting allowed under the County's glare rule?
Yes. The performance standards bar direct or reflected glare from being visible off-site but expressly allow reasonable security lighting that is properly shielded so it does not fall onto adjoining property.
What lighting standard applies in most zoning districts?
A standard provision requires that all exterior and interior lighting be designed and located so that direct rays and glare are confined to the premises, keeping light from spilling onto neighbors.
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