Home Additions in Cupertino, CA
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The 66% Rule and Privacy Planting
Two-story homes and second-story additions (R1): the overall floor area ratio cap is 45% of net lot area, and homes are limited to 28 feet and two stories. Residential Design Review by the City’s consulting architect is triggered when the second floor is more than 66% of the first floor, or when second-story side setbacks are under 15 feet on a side or 30 feet combined. Second-story decks need a Minor Residential Permit with neighbor notice. A weatherproof notice board on a 5-foot post must stay up through the appeal period, and privacy planting is required within a 30-degree view cone from second-story side and rear windows with sills 5 feet or lower, unless the affected neighbor signs a waiver.
Addition Work
Eichlers, Hillsides and Trees
- Fairgrove (R1e): about 220 early-1960s Eichlers with their own standards: roof slope up to 3:12, vertical-groove siding facing the street, first floors no more than 12 inches above grade, and obscured or louvered second-story side and rear windows.
- R1-a areas: second floors are capped at 40% of the first floor or 750 sq ft, whichever is greater, up to 1,100 sq ft.
- Hillside (RHS): 30 feet from natural grade, floor area capped at 6,500 sq ft by a slope formula, with geotechnical and arborist reports peer-reviewed by City consultants.
- Protected trees: native oaks, California buckeye, big-leaf maple, deodar cedar and blue atlas cedar with a 10-inch trunk (20 inches multi-trunk); pruning more than 25% in a year counts as removal.
- Clearances: Santa Clara County Fire, Cupertino Sanitary District, Public Works for additions of 25% or more, and school districts.
Permits
10300 Torre Avenue, Cupertino, CA 95014 · City Hall (408) 777-3200
Building and Permit Center (408) 777-3228, pe**********@*******no.gov · Planning (408) 777-3308
Counter hours vary by weekday and close noon to 1, so check ahead. Inspections are scheduled in the Online Permit Service Portal, with an email confirmation and two-hour window before 7:30 a.m. A final inspection cannot be scheduled until the contractor and every subcontractor holds a Cupertino business license.
A soils report may be waived for additions of 750 sq ft or less.
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Cupertino Home Additions FAQ
When does a second story need design review in Cupertino?
When the second floor exceeds 66% of the first floor, or second-story side setbacks are under 15 feet on a side or 30 feet combined.
What is privacy planting?
Screening trees or shrubs required in a 30-degree view cone from certain second-story windows, unless the neighbor waives it.
What are the Fairgrove Eichler rules?
R1e standards limit roof slope, require vertical-groove siding facing the street and obscured second-story side and rear windows.
Is a soils report required?
It may be waived for additions of 750 sq ft or less.