Skip to main content
Loading…
This section is included in your selections.

A. Purpose. The purpose of this section is to establish basic site requirements for residential zones in Redmond. These requirements implement Redmond’s Comprehensive Plan, the Growth Management Act, the Multicounty Planning Policies, and the County-Wide Planning Policies, while also protecting Redmond’s residential areas from public nuisances, incompatible uses, and other hazards.

B. Site Requirements in Zone Use Charts. Each zone use chart in RZC 21.08.020 through 21.08.140 sets forth the basic dimensional standards for residential development in that zoning district. RZC 21.08.150 through 21.08.200 provide additional general requirements applicable to all zoning districts. Some site requirements may be modified as provided in RZC 21.08.150 through 21.08.200.

C. Allowed Density.

1. Purpose. The purpose of the allowed density requirement is to:

a. Help maintain a consistent and compatible land use pattern in Redmond’s residential neighborhoods;

b. Serve Redmond’s planned housing needs; and

c. Prevent public nuisances that result from a lack of adequate open space and the over utilization of public facilities.

2. Requirements. The allowed density, as shown in each residential zone use chart in RZC 21.08.020 through 21.08.140, represents the maximum number of dwelling units that may occupy an acre of land, exclusive of bonuses and exclusive of accessory dwelling units.

3. Calculations. When calculating allowed density for any given site in the City, the gross area of the site is multiplied by the allowed density per acre that applies to the zone where the site is located. The result is the maximum number of units (other than ADUs) that may occupy that site. Please note that any available density bonuses are calculated on the base density.

Calculating Maximum Number of Dwelling Units:

Example: R-4 zone: Allowed density of 4 units per acre

Gross Site Area: 21,780 square feet

x

4/43,560

=

2 maximum allowed dwelling units

4. North Redmond Residential Development and Conservation Overlay Density Transfer and Limitations. The Residential Development and Conservation Overlay zone is applied to those properties within the North Redmond Neighborhood and adjacent pre-annexation areas as shown on the Zoning Map. This designation establishes a maximum for the underlying zoning at R-4 in those areas determined to be developable in the Critical Areas Report, submitted at the time of application for development. Additionally, for those areas determined to be critical areas and the associated buffers, densities may be transferred to developable areas at a maximum of one unit per acre. (See Figure 21.08.170A below.) A rezone for higher densities beyond the established R-4, four units per acre, may not occur. In addition to the allowed density, bonus incentives are applicable as designated in the North Redmond Neighborhood Plan or elsewhere in the Redmond Zoning Code.

Figure 21.08.170A
North Redmond Residential Development and Conservation Overlay Density Transfer

North Redmond Residential Development and Conservation Overlay Density Transfer

D. Minimum Required Density.

1. Purpose. The purpose of minimum required density is to:

a. Help establish a consistent and compatible land use pattern in Redmond residential neighborhoods;

b. Provide for the efficient use of land;

c. Provide for the efficient use of public facilities and services; and

d. Reduce public nuisances that often result when undeveloped areas are urbanized.

2. Relationship to Allowed Density. While allowed density places an upper limit on the number of units that may be located on a site, the minimum required density establishes a lower limit. When taken together, the site calculations for allowed density and minimum required density create an upper and lower range that defines the number of units that may be built on a site, exclusive of accessory dwelling units. One important difference between allowed density and minimum required density is that allowed density is calculated using gross site area while minimum required density uses the net buildable area of a site.

3. Requirements. The minimum required number of dwelling units for a site is equal to the site’s net buildable area multiplied by the site’s allowed or “zoned” density and multiplied again by the minimum required density percentage. The net buildable area calculation is explained below in subsection D.4 of this section. The minimum required density percentage, as well as the allowed density, for each residential zone is shown in the zone use charts in RZC 21.08.020 through 21.08.140.

4. Net Buildable Area Calculation. Net buildable area, for the purpose of determining the minimum required number of dwelling units for a site, shall be calculated by subtracting areas where building is prohibited or subject to significant restrictions from the gross area of a site. The area remaining after these exclusions from the gross site area represents the net buildable area. The following exclusions from the gross site area, and only these exclusions, may be used in determining net buildable area:

a. Critical areas and shoreline areas where development is prohibited or restricted shall be excluded from the net buildable area. These critical areas and shoreline areas shall include: Landslide Hazard Areas; Category I through IV wetlands; Class I through IV streams; floodways; floodplains; critical areas buffers; the area waterward of the line of the ordinary high water mark on Lake Sammamish, regardless of the extent of ownership; lands required to be maintained in open space; and Native Growth Protection Areas.

b. Surface water retention areas that are dedicated or otherwise held in common shall also be excluded from the net buildable area.

c. Public rights-of-way, private streets and access corridors, parks and open space that are dedicated or otherwise held in common, and above-ground public facilities shall also be excluded from the net buildable area.

d. For example, where gross site area equals 87,120 square feet or two acres, the following calculation is made to determine net buildable area:

Calculating Net Buildable Area

Example:

Gross Site Area: 87,120 square feet

Critical Areas and buffers: 6,100 square feet

Public rights-of-way: 15,680 square feet

=

Net Buildable Area: 65,340 square feet (1.5 acres)

e. In order to avoid the expense of technically assessing a site’s net buildable area, a builder/developer may elect to apply the minimum required density percentage to the gross area of the site instead of the net buildable area in order to determine the minimum required number of units.

5. Minimum Required Density Calculation. The formula for determining a site’s minimum required number of dwelling units is shown below.

Calculating Minimum Required Density

Net buildable area

x

Allowed density

x

Minimum required density percentage

=

Minimum required number of units

Example: Gross site area = 87,120 square feet (2 acres)

Net buildable area = 65,340 square feet (1.5 acres)

Allowed density = 6 units per acre

Minimum required density percentage = 80 percent

Net buildable area: 1.5 acres

x

Allowed density: 6 units per acre

x

Minimum required density percentage: 80 percent (0.8)

=

Minimum required number of units: 7 (rounded down from 7.2)

Required Unit Range for this Example:

Maximum number of units allowed, excluding bonuses = 12

See allowed density calculation in RZC 21.08.170.C.3.

Minimum required number of units = 7

6. Applicability/Exceptions. Minimum required density applies to all new residential development with the following exceptions:

a. The construction of any new dwelling unit on an existing lot of record;

b. The renovation or conversion of existing dwelling units provided that such a renovation or conversion does not result in a reduction in the number of dwelling units to a number below the minimum required;

c. An existing legal lot, with one existing home, being divided into two lots;

d. New development where 60 percent or more of the new units provided would be affordable to households earning 50 percent or less of area median income.

E. Minimum Average Lot Size.

1. Purpose. The purpose of the average lot size requirement is to:

a. Allow for the development of consistent and compatible land use patterns throughout Redmond’s residential neighborhoods; and

b. Minimize public nuisances that may result from a lack of adequate open space and the overutilization of public facilities.

2. Requirements.

a. Explanation. The zone use charts in RZC 21.08.020 through 21.08.140 establish the minimum average lot size for each residential zone in Redmond. The average lot size of all lots created through the subdivision or short subdivision process must meet, at a minimum, this average lot size requirement. However, this requirement may be modified under the following circumstances:

i. Green Building and Green Infrastructure Program. The owner may participate in the Green Building and Green Infrastructure Incentive Program (see RZC Chapter 21.67), and create a lot or lots which do not meet the minimum average lot size for the underlying zone by meeting all program requirements; or 

ii. Small Lot Short Plats. The owner of any lot in the Bear Creek, Education Hill, Idylwood, Southeast Redmond, or Overlake Residential Neighborhoods which is at least 200 percent of the required minimum average lot size in the underlying residential zone and which contains an existing detached dwelling unit may short subdivide the lot in order to create a separate fee simple lot which does not meet the minimum average lot size for the underlying zone if the dwelling unit to be constructed on the newly created lot meets all of the following requirements:

A. Only one detached dwelling unit shall be allowed on the lot.

B. The dwelling unit on the lot shall not exceed 1,000 square feet in total area, excluding any garage area. The dwelling unit and any garage shall not exceed 1,500 square feet in total area. A covenant shall be recorded against the title of the lot prohibiting expansion of the dwelling unit.

C. The dwelling unit on the lot must conform to all setback, lot coverage restrictions, and any other standards or regulations required of a detached dwelling unit in a residential zone.

D. The maximum height of any portion of the roof, except chimneys or cupolas shall not exceed 25 feet anywhere on the site.

E. Two off-street parking places are required. Parking spaces must be paved and may include private attached garages, carports, or other off-street areas reserved for vehicles. No detached garages are allowed.

F. The dwelling unit must be affordable to an individual or family that has an annual income that is 120 percent or less of the area median income defined in RZC Chapter 21.20, Affordable Housing.

b. Limitations on Averaging.

i. No lot shall be created as a result of lot averaging that results in a lot size that is less than 50 percent of the average lot size standard. For example, with an average lot size of 7,000 square feet in an R-4 zone, no single lot in a proposed subdivision in this zone may be sized at less than 3,500 square feet. For short subdivisions where three or fewer lots are created, no lot shall be created that is less than 75 percent of the average lot size standard.

ii. Critical areas and their associated buffers and shoreline areas (the area waterward of the line of the ordinary high water mark on Lake Sammamish) shall not be included in the average lot size determination for all residential zones.

iii. Nothing in this section shall be construed to allow for an increase in the allowed density as calculated in RZC 21.08.170.C.3 and as shown for all residential zones in the zone use charts in RZC 21.08.020 through 21.08.140.

c. Areas of Lots with Access Corridor. The calculation of lot area shall not include any area of the lot that serves as an access corridor.

F. Minimum Lot Width Circle.

1. Purpose. The purpose of the minimum lot width circle requirement is to:

a. Ensure that each lot is wide enough to maintain a consistent and compatible land use pattern in residential neighborhoods; and

b. Ensure that a minimum buildable area is included in each lot created.

2. Requirement.

a. The zone use chart for each residential zone (RZC 21.08.020 through 21.08.140) identifies the minimum lot width circle diameter that must fit within each newly created lot. This circle establishes that at least some portion of a lot must be at least as wide as the minimum lot width. The lot width circle shall not include the area waterward of the line of ordinary high water mark on Class I through Class IV streams and Lake Sammamish, regardless of the extent of ownership; floodways; Category I wetlands; or Landslide Hazard Areas. (SMP)

b. In the area between Lake Sammamish and West Lake Sammamish Parkway, the minimum lot width circle diameter shall be 45 feet.

c. The minimum lot width circle requirement does not apply where structures overlap two or more lot lines.

Figure 21.08.170B
Minimum Lot Width Circle

Minimum Lot Width Circle

G. Minimum Lot Frontage.

1. Purpose. The purpose of the minimum lot frontage requirement is to:

a. Prevent congestion by allowing for on-site parking; and

b. Reduce public nuisances that result from an inability of emergency vehicles to access a building either because vehicles block the access to a residence or because the lot is not wide enough to allow emergency vehicles to enter from the street.

2. Requirement. Minimum lot frontage is the minimum width of a lot, as defined by the zone use chart for each residential zone (RZC 21.08.020 through 21.08.140), where it shall adjoin a street or approved access corridor. For individual flag lots, lot frontage is measured where the access corridor meets the street. For private streets and access corridors serving less than three lots and accessing directly onto a public street, lot frontage may be reduced to 14 feet.

Figure 21.08.170C
Minimum Lot Frontage

Minimum Lot Frontage

H. Building Setbacks.

1. Purpose. The purpose of front, rear, side/interior, and side street setbacks is to:

a. Help maintain a consistent and compatible land use pattern for Redmond’s residential neighborhoods;

b. Provide for adequate light and air to all properties;

c. Minimize incompatibilities, such as excessive light and noise; and

d. Prevent public nuisances, such as the potential for fire damage from buildings constructed too close to each other.

2. Requirements.

a. Lot Orientation. For the purpose of applying setback regulations, the following shall be applied: the front shall be toward the street or access corridor from which the lot is addressed; the rear is opposite to the front or as nearly so as the lot shape permits; and the sides are 90 degrees to the front or as nearly so as the lot shape permits. Where a lot does not front on a named street and it is most logical to have the front oriented towards the unnamed access corridor, the side towards the unnamed access corridor shall be considered the front and all other setbacks will follow suit.

Figure 21.08.170D
Lot Orientation

Lot Orientation

b. Measurement. All setbacks shall be measured at right angles, or as near to right angles as possible, to the nearest property line in a plane horizontal to the ground, or in the case of access corridors for single-family residential development, from the nearest edge of the easement to the foundation line of the structure. Front, side street, side/interior, and rear directions shall be determined as provided in subsection H.2.a of this section.

Figure 21.08.170E
Building Setbacks

Building Setbacks

c. Side Street Setbacks. Side street setbacks shall apply whenever a side yard adjacent to a structure faces a public street, private street, or access corridor.

d. Corner Lots. Corner lots shall be subject to only one front setback requirement.

e. Side/Interior Setbacks. In those zones where the side/interior setback is five feet and ten feet, each lot shall have one five-foot side/interior setback and one ten-foot side/interior setback. Where an abutting property has a five-foot side/interior setback, the side/interior setback on that side shall be ten feet. In no case shall any property be required to have two ten-foot side/interior setbacks. Where both properties abutting a lot have five-foot side/interior setbacks, only one ten-foot side/interior setback shall be required.

f. Rear Setbacks – Alleys. When vehicular access to a lot is by an alley, the rear setback shall be four feet from the nearest alley line.

g. Repealed.

Figure 21.08.170F
Permitted Encroachments in Setback Areas

Permitted Encroachments in Setback Area

3. Encroachments/Front, Rear, Side Setbacks. Minor structures, appurtenances and improvements may encroach into required front, rear, and side setbacks as follows:

a. The following features are permitted to encroach up to three feet into front, rear, and side street setback areas: chimneys, porches, bay windows, roof structures, other building extremities, such as gas fireplace enclosures, and decks. No encroachment into a front, rear, or side street setback area may extend closer than three feet to the nearest property line.

b. Encroachments/Side Interior Setbacks. The following features may encroach up to five feet into side interior setback areas: chimneys, porches, bay windows, roof structures, other building extremities, such as gas fireplace enclosures, and decks. No encroachment into a side interior setback area may extend closer than three feet to the nearest property line.

c. No encroachments are allowed with the Lake Sammamish waterfront building setbacks, except as provided in subsection A.5, Waterfront Building Setbacks along Lake Sammamish. (SMP)

d. Improvements. Improvements less than 30 inches above grade including decks, patios, walks and driveways are permitted in setback areas. Fences, landscaping, flagpoles, street furniture, transit shelters and slope stability structures are permitted in setback areas, provided that all other applicable requirements are met.

4. Setback Modifications.

a. Multifamily/Front Setbacks. A binding site plan, site plan, or preliminary plat may modify front setbacks along access corridors within multifamily developments, provided that front setbacks are maintained from all public streets.

b. Zero Lot Line Development. Within zero lot line developments, buildings may be located within the side yard setback according to the requirements set forth in RZC 21.08.390, Zero Lot Line Development.

c. Waterfront Building Setbacks along Lake Sammamish (SMP).

i. Waterfront building setbacks shall be a distance measured from the line of the ordinary high water mark on Lake Sammamish. The ordinary high water mark, as defined in RZC 21.78, Definitions, shall be located for each shoreline property through a site reconnaissance and survey by a licensed surveyor.

ii. See RZC 21.68.060.B, Lake Sammamish Setback, for setback requirements and restrictions. Habitat enhancement features or shoreline protective structures, subject to the requirements of RZC 21.68.080, Shoreline Protective Structures, and in-water structures, subject to the requirements of RZC 21.68.070, In-Water Structures, are permitted. Setback vegetation should consist of native trees, shrubs, or groundcover with an emphasis on encouraging a tree canopy.

iii. Parking is prohibited within the waterfront building setback.

I. Building Separation.

1. Purpose. The purpose of the building separation requirement is to:

a. Helps maintain a consistent and compatible land use pattern for Redmond’s residential neighborhoods;

b. Provide for adequate light and air to all properties;

c. Minimize incompatibilities, such as excessive light and noise;

d. Prevent public nuisances such as the potential for fire damage from buildings constructed too close to each other; and

e. Allow for easy access to structures in the event of fire or other emergency.

2. Requirement. Buildings, except for accessory structures, shall maintain the separation required in the zone use chart for the residential zone in which the building is located. (See RZC 21.08.020 through 21.08.140.)

J. Maximum Lot Coverage for Structures.

1. Purpose. The purpose of the maximum lot coverage for structures requirement is to:

a. Help maintain a consistent and compatible land use pattern for Redmond’s residential neighborhoods;

b. Provide for adequate light and air to all properties; and

c. Prevent public nuisances that may result from a reduction of open space, such as increased stormwater runoff and other environmental hazards.

2. Requirement. The maximum lot coverage for structures requirement sets the maximum percentage of a lot that may be covered with primary and accessory structures. Lot coverage percentages for each residential zone are established in the zone summary for each residential zone. (See RZC 21.08.020 through 21.08.140.) Decks exceeding a height of thirty inches above grade, patios, and porches with roofs shall be counted toward the maximum lot coverage of structures.

K. Maximum Impervious Surface.

1. Purpose. The purpose of the maximum impervious surface requirement is to:

a. Maintain open space;

b. Prevent adverse impacts from stormwater runoff;

c. Replenish ground water resources; and

d. Minimize flooding.

2. Requirement. The maximum impervious surface percentage in the zone use chart for each residential zone (RZC 21.08.020 through 21.08.140) establishes the maximum percentage of a lot’s area that may be covered with structures (including outdoor storage), paved areas, and other impervious surfaces.

3. Modifications. As part of an approved binding site plan or subdivision, the Technical Committee may allow for increased maximum impervious surface limits on individual lots within a multi-lot development provided that the total amount of impervious surface for the development as a whole does not exceed the limit established for that zone in the zone summary. If a modification is approved, the development shall be conditioned to ensure compliance with the maximum impervious surface limits set by the zone summary for the residential zoning district. (See RZC 21.08.020 through 21.08.140.)

L. Minimum Open Space – Landscaping – Buffers.

1. Purpose. The purpose of the minimum open space requirement is to:

a. Maintain community character by providing visual relief, open space, adequate outdoor space for residents of residential developments; and

b. Enhance public safety by providing adequate off-street recreation space for children.

2. Requirement. The minimum open space requirement establishes the minimum percentage of a lot or a development that must be set aside as open space, as shown for each residential zone in the zone use chart. (See RZC 21.08.020 through 21.08.140.)

a. Lot-By-Lot Compliance. Where the minimum open space requirement is met on a lot-by-lot basis, open space shall consist of a contiguous area of natural vegetation, landscaping, or recreation and may include front or backyard areas. Decks and porches shall be counted towards the minimum open space requirement. No portion of the open space created under this option may have a dimension of less than 15 feet.

b. Development-Wide Compliance. The minimum open space requirement may be measured on a development-wide basis as opposed to a lot-by-lot basis. Under this option, individual lots may be developed with as little as 10 percent of total lot square footage in open space (as defined in subsection L.2.a of this section), provided that the development as a whole meets the open space requirement called for in zone use chart for the residential zone in which the property is located. (See RZC 21.08.020 through 21.08.140.) Common open space created under this modification shall be dedicated and shall:

i. Serve those lots developed below the open space standard in the zone summary;

ii. Include an active open space area designed for recreation including picnic areas, children’s play areas, and sports courts;

iii. Consist of a contiguous area and have no single dimension of less than 25 feet; and

iv. Have a minimum size equal to the total square foot reduction below the open space standard of the Site Requirements Chart for every lot in the development.

c. Provisions Applicable to Both Lot-By-Lot and Development-Wide Compliance.

i. Environmentally critical areas, buffers, front and rear lot setbacks, swimming pools, sport courts, recreational buildingsgolf courses, outdoor patios and similar structures or facilities may be used to meet the minimum open space requirement.

ii. At least 25 percent of the minimum open space required by subsection L.2 of this section shall be outside of wetlands, streams, lakes, and critical area buffers and on slopes of 10 percent or less and developed and maintained so it is usable for active recreation activities. Playgrounds, recreational buildings, swimming pools, golf courses, sport courts, and similar structures or facilities may be used to meet this requirement.

M. Maximum Height of Structures.

1. Purpose. The purpose of the maximum height of structures requirement is to:

a. Help to maintain a consistent land use pattern and visual character in residential neighborhoods;

b. Protect important community-recognized view corridors; and

c. In the case of shoreline height limits, to protect habitat values and the aesthetic resources of the shoreline and aid in preserving views in shoreline areas.

2. Requirements. The maximum height of structures requirement sets the limit above which structures shall not extend, as set forth in the zone use chart for each residential zone. (See RZC 21.08.020 through 21.08.140.)

a. Hose towers (when associated with a fire station), chimneys, antennae, smoke and ventilation stacks flagpoles, heating, cooling and ventilation equipment, mechanical equipment screens and enclosures, roof access stair enclosures, solar panels, and wind turbines may exceed the highest point of the existing or proposed structure by no more than 15 feet.

b. Religious Icons and Structures. Special height exceptions for steeples, bell towers, crosses or other symbolic religious icons are contained in RZC 21.08.280, Churches, Synagogues, Temples, and Other Places of Worship.

3. Maximum Height of Structures – Height Limits within Shorelines (SMP). Within the Shoreline Jurisdiction, the following height limits apply:

a. The maximum height of all structures, except water-oriented accessory structures and piers or docks, shall be 30 feet.

b. Water-oriented accessory structures shall not exceed ten feet in height.

c. The maximum height of docks is specified in RZC 21.68.070, In-Water Structures.

d. The maximum height of structures, including bridges, that support a regional light rail transit system may be higher than 30 feet but shall be no higher than is reasonably necessary to address the engineering, operational, environmental, and regulatory issues at the location of the structure. (Ord. 2652; Ord. 2709; Ord. 2733; Ord. 2753; Ord. 2803; Ord. 3028)

Effective on: 2/27/2021