Article I Zone Based Regulations

RZC 21.03 R-4 Single-Family Urban Residential

A.
Purpose. The R-4 Single-Family Urban Residential zone provides for primarily single-family residential neighborhoods on lands suitable for residential development with an allowed base density of four dwellings per gross acre. This designation provides for stable and attractive suburban residential neighborhoods that have a full range of public services and facilities. To complement the primarily residential nature of these zones, some nonresidential uses are allowed.

Figure RZC 21.03A Typical Subdivision Layout R-4

Figure RZC 21.03B
Typical Site Layout R-4

This sketch represents maximum allowance for structures, impervious surface & setbacks

Typical Site Layout R-4

LEGEND
A	FRONT SETBACK MINIMUM 15'-0"
B	SIDE STREET SETBACK MINIMUM 15'-0"
C	SIDE INTERIOR SETBACK 5'-0"/10'-0"
D	REAR SETBACK MINIMUM 10'-0"
E	LOT FRONTAGE MINIMUM 20'-0"
F	ALLOWED PROJECTION OF BUILDING EXTREMITIES INTO SETBACK
G	LOT WIDTH CIRCLE MINIMUM 40'-0" (DIAMETER)
H	GARAGE SETBACK MINIMUM 18'-0"
I	LOT-BY-LOT OPEN SPACE MINIMUM 15'-0"
J	BUILDING SEPARATION MINIMUM 10'-0"

B.
Maximum Development Yield. The following calculation provides a potential maximum development yield for a development utilizing the density bonuses available for the R-4 zone. The calculation is based on a development occurring on a one-acre lot. Please note that accessory dwelling units do not count toward maximum development yield.

Table RZC 21.03A Maximum Development Yield
Base Density	Available Density Bonuses	Maximum Density
4 dwelling units per gross acre	Cottage Development: Up to 1.75 cottages allowed in place of each standard size dwelling unit	7 dwelling units allowed
	Green Building/Green Infrastructure Development: Up to 10 percent of base density	0.40 dwelling units allowed
	Affordable Housing: Up to 15 percent of base density	0.60 dwelling units allowed
		Total = 8 dwelling units per gross acre

C.
Regulations Common to All Uses.

Table RZC 21.03B Regulations Common to All Uses
	Regulation	Standard	Exceptions
Minimum	Average Lot Size	7,000 square feet
	Required Density	80 percent of net acres
	Lot Width Circle	40 feet
	Lot Frontage	20 feet
	Setbacks
	Front	15 feet	For zero lot line development, a dwelling unit may be placed on one interior side property line, giving it one zero side/interior setback. If it is an interior lot line, the setback from the other side property line shall be 10 feet. See RZC 21.03.033, Zero Lot Line Development, for additional requirements.
	Garage	18 feet
	Side / Interior (each side)	5 feet / 10 feet
	Side Street	15 feet
	Rear	10 feet
	Alley	4 feet
	Lake Sammamish	35 feet
	Building Separation	10 feet	Minimum building separation shall be 15 feet in the following neighborhoods: Education Hill, North Redmond, and Willows/Rose Hill. In all neighborhoods, minimum building separation shall be 10 feet for cottages, size-limited dwellings, small-lot short plats, accessory dwelling units, and locations where these structures or cottages adjoin larger dwelling units.
	Open Space	20 percent of total lot area
Maximum	Lot Coverage for Structures	35 percent of total lot area
	Impervious Surface	60 percent of total lot area
	Building Height	35 feet	30 feet within the Shoreline Jurisdiction
	Drive-through	n/a	Drive-through facilities are prohibited except where expressly permitted in the Allowed Uses and Special Regulations table below.

D.
Allowed Uses and Special Regulations. The following table contains special zoning regulations that apply to uses in the R-4 zone. To use the chart, first read down the left-hand column titled “Use.” When you have located the use that interests you, read across to find regulations that apply to that use. Uses are permitted unless otherwise specified in the Special Regulations column. Permitted uses may require land use permit approval. See RZC 21.42.002, Overview of the Development Process, for more information. Uses not listed are not permitted.

Table RZC 21.03C Allowed Uses and Special Regulations
Section	Use	Parking Ratio: Unit of measure (Minimum required; Maximum allowed)	Special Regulations
Residential
1	Detached dwelling unit	Dwelling unit (2.0)
2	Cottage	Cottage (1.5, 2.0)	Permitted use only in Bear Creek, Education Hill, Grass Lawn, North Redmond, Overlake Residential, and Willows/Rose Hill neighborhoods. See RZC 21.03.023, Cottage Housing Developments, for specific site development requirements and supplemental neighborhood regulations which may apply.
3	Small-lot short plat	Dwelling unit (2.0)	Permitted use only in Education Hill, Idylwood, and Overlake Residential neighborhoods. See RZC 21.03.011.E.2.a.ii, Small Lot Short Plats, for specific regulations which may apply.
4	Size-limited dwelling	Dwelling unit (2.0)
5	Accessory dwelling unit (ADU)	ADU (1.0)	1. See RZC 21.03.016, Accessory Dwelling Units, for specific regulations which may apply. 2. ADUs are not allowed within cottage developments in the Willows/Rose Hill and Education Hill neighborhoods.
6	Attached dwelling unit, 2-4 units	Dwelling unit (2.0)	1. Permitted use in Education Hill, Grass Lawn, North Redmond, Southeast Redmond, and Overlake Residential neighborhoods. In Willows/Rose Hill neighborhood, 2-unit attached dwelling units are permitted use; 3-unit and 4-unit attached dwelling units require a Conditional Use Permit as part of a demonstration program. A Conditional Use Permit is required for attached dwelling units in all other neighborhoods not listed above. 2. Please see RZC 21.03.020, Attached Dwelling Units, for supplemental neighborhood regulations related to density, design, and review and decision procedures.
7	Manufactured home	Dwelling unit (2.0)	Please see RZC 21.03.026, Designated Manufactured Homes, Manufactured Homes, and Mobile Homes, for specific regulations which may apply.
8	Retirement residence	See Special Regulations	1. Permitted if developed through the subdivision or binding site plan processes. Otherwise, a Conditional Use Permit is required. See RZC 21.03.031, Retirement Residences, for specific regulations which may apply. 2. Parking requirements are as follows: a. With no skilled nursing facility: Unit (1.0, 1.0) b. With skilled nursing facility: Worker on largest shift (1.25, 1.25) 3. A Traffic Mitigation Plan is required. See RZC 21.03.031.C.3.b.iii.
9	Residential care facility		A Conditional Use Permit is required.
10	Adult family home	Dwelling unit (2.0)
General Sales or Service
11	Bed and Breakfast Inn	Rental room (1.0)	Permitted use if no more than two rooms. A Conditional Use Permit is required for inns with between three and eight rooms.
Transportation, Communication, Information, and Utilities
12	Road, Ground, Passenger and Transit Transportation	N/A	Regional light rail transit system only. No vehicle storage.
13	Local utilities	Adequate to accommodate peak use.
14	Regional utilities	Adequate to accommodate peak use.	A Conditional Use Permit is required.
15	Heliport	N/A	A Conditional Use Permit is required. Does not include medical airlift. Permitted only abutting Lake Sammamish.
16	Float plane facility		1. A Conditional Use Permit is required. Permitted only abutting Lake Sammamish. 2. Piers, docks, and floats associated with the operation of float planes shall meet, as a minimum, the location criteria contained in RZC 21.38.007, In-Water Structures. Piers and docks are also subject to standards for residential piers and docks contained in RZC 21.38.007.E, Piers, Docks, and Floats. (SMP) 3. Only one float plane per lot is permitted. (SMP) 4. Float planes shall observe speed regulations for watercraft and vessels contained in RMC 14.16.030, Speed Regulations, except that these speeds may be exceeded for a short duration of time during landing and takeoff of planes. (SMP) 5. Float plane facilities or operation of float planes is prohibited on the Sammamish River, Bear Creek and Evans Creek. (SMP) 6. Float plane facilities and operation shall comply with FAA standards, including standards for fueling, oil spill cleanup, firefighting equipment, and vehicle and pedestrian separation. (SMP)
17	Wireless Communication Facilities		See RZC 21.31, Wireless Communication Facilities, for specific regulations that may apply.
Arts, Entertainment, and Recreation
18	Community indoor recreation	Adequate to accommodate peak use.	Includes noncommercial indoor recreation uses, such as community clubhouses, indoor swimming pools, and other similar facilities.
19	Parks, open space, trails and gardens	1,000 sq ft gfa (0, adequate to accommodate peak use.)	Permitted if public or noncommercial. A Conditional Use Permit is required for commercial facilities.
20	Athletic, sports, and play fields	Adequate to accommodate peak use.	A Conditional Use Permit is required.
21	Golf course
22	Marine recreation
23	Commercial swimming pool
Education, Public Administration, Health Care, and Other Institutions
24	Day care center	Employee (1.0)	A Conditional Use Permit is required. Day care uses are only permitted in a building or building complex used for other uses, such as a school, church, meeting hall, or some other building used for more than one purpose. See RZC 21.03.025, Day Care Centers, for specific regulations which may apply.
25	Family day care provider	Vehicle used by the business (1.0).	Family day care providers are permitted as home businesses. See RZC 21.03.028, Home Business, for specific regulations which may apply.
26	Public safety	Adequate to accommodate peak use	A Conditional Use Permit is required.
27	Grade schools (K-12)	Adequate to accommodate peak use	A Conditional Use Permit is required.
28	Religious Institution	1,000 sq ft gfa for assembly (1.0) or 5 fixed seats (1.0); 3 seats (1.0).	1. Permitted use if less than 250 seats. A Conditional Use Permit is required for religious institutions with between 250 and 750 seats. See RZC 21.03.022, Churches, Temples, Synagogues and Other Places of Worship, for specific regulations which may apply. 2. A Traffic Mitigation Plan is required. See RZC 21.03.022.C.5.
Agriculture
29	Crop production	N/A
30	Equestrian facility	N/A	A Conditional Use Permit is required.
Other
31	Home Business	Vehicle used by the business (1.0).	See RZC 21.03.028, Home Business, for specific regulations which may apply.
32	Roadside produce stand	N/A
33	Pier, dock, float		See RZC 21.38.007, In-Water Structures, for special height, setback and area requirements. (SMP)
36	Water-oriented accessory structure		See RZC 21.38.007.G, Water-Oriented Accessory Structures, for special height, setback and area requirements. (SMP)

(Ord. 2652; Ord. 2744; Ord. 2753; Ord. 2803; Ord.2836; Ord. 2951)

Section Comments
By: enCode Staff Date: 7/25/2018	Please change
By: enCode Staff Date: 7/31/2019	pwer net acre.
By: enCode Staff Date: 7/31/2019	No, it is gross acre.
By: enCode Staff Date: 8/1/2019	THIS SHOULD BE FIVE UNITS PER ACRE.
By: enCode Staff Date: 8/1/2019	SO NOTED. DONE.

21.03.017 Accessory Structures

Accessory Structures User Guide

A.
Purpose. The purpose of the accessory structures provisions is to allow for the opportunity to add additional structures to residential property for the purpose of increased storage space, work space, or other uses that would not qualify it as a dwelling unit.
B.
Applicability. Accessory structures are allowed in all residential zones of the City, as an accessory use to an existing dwelling unit.
C.
Requirements.
1. 1.
  Height. Accessory structures may not exceed 22 feet in height, with the exception of accessory structures which contain accessory dwelling units, which shall not exceed 28 feet in height.
2. 2.
  Size.
  1. a.
    Total square footage for the footprint of the accessory structures may not exceed 60 percent of the footprint of the living area on the ground floor (excluding garage) of the primary dwelling unit.
  2. b.
    Total square footage for accessory structures which contain accessory dwelling units may not exceed 60 percent of the total square footage (excluding garage) of the primary dwelling unit.
  3. c.
    In no case shall the total square footage of the accessory dwelling unit portion of an accessory structure exceed 1,000 square feet.
3. 3.
  Building Separation. Unless the International Building Code or International Fire Code dictates otherwise, there shall be no minimum building separation for accessory structures.
4. 4.
  Location. Accessory structures are prohibited within the front yard setback, with the exception of garages where lot size or lot configuration are not supportive of lessening the dominant appearance of a garage, such as where lot width measured at the front street is less than 50 feet, where steep grades are present, or when compliance with this section would endanger or impair pedestrian and vehicular safety.
5. 5.
  Accessory Structure Setbacks. Side interior and rear setbacks (but not side street) for accessory structures in all residential zones are five feet.

(Ord. 2951)

Effective on: 3/29/2014