Global Announcement Text

Mountain View, California: ADU Regulations

City or County:

Mountain View, California

Date Updated:

11.26.2020

Zoning:

R1 / R2 / R3 / RMH / R4

Types of ADUs:

Attached, Detached, Garage Conversion and Junior

Stories:

N/A

Lot Size:

No minimum

Maximum ADU Floor Area:

Single-family ADU: Maximum: 850 sq.ft. of habitable floor area for one bedroom or fewer, and 1,000 sq.ft. for 2 bedrooms or more.
Multi-family ADU: Not mentioned
Junior ADU: 500 sq.ft. of habitable floor area

Lot Coverage:

Must comply with underlying zoning regulations.

Bedroom:

No min/max.

Storage:

No min/max.

Kitchen:

Require separate kitchen facilities (permanent range, counters, refrigerator, sink).

Bath:

Require separate bathroom facilities. Junior and single-family conversion exempt from requirement to install new utility connection.

Note: Drainage and sewer connections should be assessed on a project by project basis.

Parking:

Single-family ADU:
No bedrooms - No parking required.
One or more bedrooms - One space (covered or uncovered), which can be provided in a garage or carport or as tandem parking in a driveway. State parking exceptions apply (public transit, historic district, no permits for ADU occupants, car share, attached/conversion/junior), as well as when a garage, carport, or covered parking structure is demolished to build ADU.

Multi-family: No parking space required.

Setbacks:

Single-family ADU: Front setbacks consistent with requirements of the underlying zone, side and rear 4’.

Multi-family ADU: Front setbacks consistent with requirements of the underlying zone, side and rear 4’.

Note: Fire Department regulations should be assessed on a project by project basis.

Height:

Detached: 16 ft. max

Attached: 28 ft. max (second story unit, though ADU must be contained within one story)

Location:

Not included in new code 

Junior ADU: Must be contained entirely within the walls of a single-family dwelling.

Rear Yard Coverage:

Not included in new code

Design:

The design must conform in general to design of primary dwelling.

Note: Historic Neighborhoods or Districts should be assessed on a project by project basis.

Entryways:

Single- family ADU must have separate exterior entry.
Junior ADU may have, but does not to have, a seperate entrance to the primary residence.

Source Code:

Important Note: Rules and regulations are updated and changed frequently. It’s one of our jobs to be up to speed and navigate those regulations. Let us know if our website isn’t up to date or if you have any information that could help. Cheers!