The Downtown Residential Zone is intended to create and maintain medium and higher density residential neighborhood that blend a range of housing types and uses, including single family and multi-family residential, with a mix of unit sizes with a limited mix of neighborhood-scale office and institutional uses. The City's goals include preservation of the existing stock of rental housing in these areas and provision of opportunities for development of new housing that increases the diversity of housing options within the City.
A. 
Downtown Residential District. The downtown residential areas surrounding the Downtown Commercial Zone is made up of an eclectic mix of single family and multi-family properties with a range in sizes and provides a mix of multi-family residential and single land uses that support the varied physical and social characteristic of the residential downtown. This zone accommodates both higher density residential and, at transition areas, medium density residential in accordance with the adopted Land Use Map.
(Ord. 1278 § 11, July 18, 2016)
The regulations of this chapter apply to all development and change of use within these zones. Development and changes of use must meet both the applicable development standards contained in this chapter as well as the City of Mill Valley's Residential Design Guidelines (either multi-family residential or single family residential, depending on the use proposed). Additional standards related to multi-family residential development contained throughout this title also apply as noted in "Additional Standards and Provisions" listed in Section 20.26.030.
(Ord. 1278 § 11, July 18, 2016)
P = Permitted
CUP = Conditional Use Permit
N = Not permitted
Downtown Residential
Additional Standards/Provisions
Residential uses
 
 
Rental multi-family housing
P
 
For-sale multi-family housing
CUP
See Note 1
Home occupations
P
20.60.250
Accessory structures
P
20.60.075
Single room occupancy (SRO) dwellings
CUP
 
Residential facility, small
P
 
Residential facility, large
 
 
Nursing home
CUP
 
Mixed-use buildings combining residential, commercial, and/or business and professional office building
CUP
 
Single family dwellings
P
See Note 2
Residential second units
P
See Note 3
Live-work (other than mixed-use bldgs)
N
 
Nonresidential uses
 
 
Office buildings
CUP
 
Hospitals, medical clinic or offices
CUP
 
Funeral parlors
CUP
 
Community centers
CUP
 
Social halls, lodge, or club buildings
CUP
 
Horticultural nurseries
CUP
 
Public utility structures
CUP
 
Day care centers for children
CUP
 
Schools
CUP
 
Public utility structures
CUP
 
Parking lots (not associated w/a use)
CUP
 
Notes:
1.
For-sale housing that is subject to Inclusionary Housing Ordinance (Chapter 20.80) is exempt from conditional use requirement per California Government Code Section 65589.4.
2.
In the Downtown Residential Zones, single family residences are permitted on all vacant lots and lots containing existing single family residences at the time of the adoption of these regulations. Consolidation of existing multi-family units to form new single family uses is not permitted.
3.
Second dwelling units in connection with a permitted single family residential use are allowed subject to Chapter 20.90.
(Ord. 1278 § 11, July 18, 2016; Ord. 1351, 5/6/2024; Ord. 1354, 9/16/2024)
A. 
Downtown Residential Development Base Standards. Development standards apply to all development within the zone:
Zoning District:
Downtown Residential (DR)
Minimum Useable Outdoor Living Area (1)
 
Total required Outdoor Space:
72 s.f. per unit
Of required outdoor living space, the minimum Shared Outdoor Space per unit:
36 s.f. per unit for developments over 8 units
Of required outdoor living space, the minimum Private Outdoor Space per unit:
50 s.f.
Max. Lot Coverage
50%
Floor Area Ratio (FAR) (i)
Multi-family residential development: Max.= 0.60; may be increased to 0.75 FAR in accordance with Section 20.26.020.B.4
Single family residential development: in accordance with RS-zone requirements found in Section 20.16.040.A
Max. Height (2)
 
Height
Max. = 25 ft. at initial setback
Height may be increased to a maximum of 35 ft. as follows:
a. At any exterior property line, the height may be increased at a 1:1 stepback ratio (1 additional foot of height for every additional 1-ft. setback) starting at the 25-ft. setback
b. At any interior (side and rear) setback, the height may be increased at a 1:1 stepback ratio (1 additional foot of height for every additional 1-ft. setback) starting at the 10-ft. setback
Stepback (2)
A 1:1 stepback ratio (1 additional foot of height for every additional 1 ft. setback) is required above 25 ft. or the second story regardless of where the second story roofline is located
Setbacks
 
Exterior (front)
Habitable Structures: 15 ft. A reduction may be granted per Section 20.26.040(7)
Garage: 18 ft. (when not reduced per Section 20.60.080). 18 ft. to face of garage to remain clear
Interior (side/rear) (1)
Min. of 5 ft. to a max. 10 ft. (1 ft. for every 1,000 sq. ft. of lot area required)
(Lots 25 ft. or less may be reduced to 3 ft. on first floor, except where windows are located, where 5 ft. required)
Parking (1)
Parking per Section 20.60.090
Notes:
1.
See Section 20.24.040(B) for additional development standards.
2.
Height exceptions permitted per Section 20.60.060. Dormers, gables, and other components of the structure shall be within the stepback envelope.
B. 
Additional Development Standards.
1. 
Efficiency Units. Efficiency units (also known as "micro-units") shall be between 350 and 450 square feet and shall be limited to 20% of the total units in any individual project site. A minimum of one efficiency unit shall be allowed on any site. Efficiency units shall count as 0.5 unit for purposes of density and parking.
2. 
Duplex. A duplex shall include two primary dwelling units, where either:
a. 
Both units are greater than 1,000 square feet; or
b. 
The square footage ratio between the two units is no greater than 2:3 (for example, if one unit were 900 square feet, the other would need to be at least 600 square feet).
3. 
Useable Outdoor Living Space. Useable outdoor living space shall be a minimum horizontal depth of six feet above the ground level and five feet by 10 feet at the ground level. Required yards less than 10 feet in width adjacent to a building or structure, and areas paved for the storage or movement of motor vehicles or bicycles cannot be considered usable outdoor living space. Accessory buildings or structures may be located within required usable outdoor area when the principal uses of such buildings or structures are accessory to those of the usable outdoor areas within which they are located.
4. 
Adjusted Floor Area—Increase to 0.75 FAR. With a Design Review application, the Planning Commission may grant an increase in the maximum adjusted FAR up to 0.75 if:
a.
The development is limited to two stories;
b.
The development screens the parking from the public right(s)-of-way; and
c.
The development meets all applicable Design Review Guidelines; or
a.
The development is a cottage development;
b.
The development is limited to two stories; and
c.
The development meets all applicable Design Review Guidelines.
5. 
Adjusted Floor Area—Parking Exclusions. The first 250 square feet of garage space for multi-family development for each parking space is excluded from the allowable FAR. Underground or partially underground parking is exempt from the FAR calculations if it is a predominately subterranean enclosed area that extends no more than three feet above the existing or finished grade, whichever is lower, except as required for vehicle entry.
6. 
Reduced Standards for Narrow Lots. For lots 25 feet wide or less, the following shall apply:
a. 
Interior side and rear setbacks for lots of 25 feet or less in width is a minimum of three feet. A minimum five-foot setback will remain where windows are placed along the setback line. The five-foot setback will apply to the window and a five-foot section of the building wall on each side of the window. Exterior walls along the minimum setback line shall include a recess or offset of at least two feet for every 35 feet of wall (for a minimum of five feet).
b. 
Lots of 25 feet or less in width shall provide parking per dwelling unit as specified in Section 20.60.090(I)(7), but shall not be required to provide guest parking per Section 20.60.090(B)(7).
7. 
Reduce Exterior Setbacks. With a Design Review application, the review body (Zoning Administrator or Planning Commission) may grant a reduction to the 15-foot front setback requirement to not less than five feet, for properties within the Downtown Residential Zone on Lower Alcatraz, Bayview, and West Blithedale (See Figure 20.26.040(B)(7)), if the following can be demonstrated:
a. 
The setback is no less than the average of the two adjoining properties;
b. 
The structure within the reduced front setback area shall be limited to 50% of the width of the frontage; and
c. 
The project meets all applicable Design Review Guidelines.
For all other properties within the Downtown Residential Zone, with a Design Review application, the review body (Zoning Administrator or Planning Commission) may grant a reduction to the 15-foot front setback requirement, to not less than 10 feet if the following can be demonstrated:
a.
The setback is no less than the average of the two adjoining properties;
b.
The structure within the reduced front setback area shall be limited to 50% of the width of the frontage; and
c.
The project meets all applicable Design Review Guidelines.
Figure 20.26.040(B)(7)
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8. 
Entries. Primary entry areas shall face a public street or SLP (steps, lanes or paths) in Downtown Residential Zones.
(Ord. 1278 § 11, July 18, 2016)