Garage Conversions: Mountain View vs Sunnyvale
How do garage conversions rules compare between Mountain View, CA and Sunnyvale, CA?
Sunnyvale has fewer restrictions than Mountain View.
Mountain View, CA
Santa Clara County
Converting a garage to living space or ADU in Mountain View is allowed with permits. State ADU law waives replacement parking when the garage is converted to an ADU.
View full Mountain View rules →Sunnyvale, CA
Santa Clara County
Sunnyvale allows garage conversions to ADUs or JADUs under state law. Detached garage ADUs are ministerial. Replacement parking is no longer required under California AB 68 and updated ADU rules.
View full Sunnyvale rules →Key Facts Comparison
| Fact | Mountain View | Sunnyvale |
|---|---|---|
| Permit | Always required | - |
| Min ceiling | 7 feet | - |
| Bedroom egress | Required | - |
| ADU parking | No replacement needed | - |
| Non-ADU parking | May be required | - |
| Ministerial approval | - | Yes under state law |
| Replacement parking | - | Not required |
| JADU max | - | 500 square feet |
| Expansion allowance | - | 150 sq ft for egress |
| Permit required | - | Yes, building permit |
Highlighted rows indicate differences between cities.
Mountain View FAQ
Do I have to add a driveway parking space?
Not when converting a garage to an ADU under state law; other conversions may require you to preserve required off-street spaces under local zoning.
Can I DIY the conversion?
Owner-builders can pull permits, but inspections and licensed electrical or plumbing subcontracts are required. Unpermitted work is cited on sale.
Sunnyvale FAQ
Do I need to add a new parking space when converting my garage?
No, AB 68 eliminated the requirement to replace displaced garage parking for ADU conversions.
What if my garage was already converted without a permit?
You can apply to legalize it. Sunnyvale offers amnesty processes for unpermitted ADUs that meet current health and safety rules.
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