Portola Valley ADU topic page
Portola Valley ADU Rules
Start with the official local ADU rules, then confirm lot-specific limits before requesting provider quotes.
Short answer
Start with the official local ADU rules, then confirm lot-specific limits before requesting provider quotes.
Source requirement: Official city or county rule source parsed and cited.
Local rule evidence
Size
External ADU: 800 to 1,500 square feet depending on proposed setbacks/FAR JADU: 500 square feet Internal ADU: 1700 square feet *Not more than 50% of primary dwelling square footage, unless 50% of primary dwelling is less than 800 square feet.
Setbacks and parking
less than base zoning district: 16 feet vertical/maximum height Compliant setbacks: 18 feet vertical height/24 feet maximum height *Higher builds require discretionary approval unless preempted by State Law Setbacks Less than base zoning district: Subject to additional...