Article 5 Lot Design Standards Revised 5/17

5.1 Purpose

The lot design standards of this article include maximum density and certain restrictions for residential and non-residential development within the county. The standards generally allow for variety in housing and building types while maintaining the overall character of neighborhoods and commercial areas of the county. The approach to lot development standards has several public benefits:

A.    It allows for development that is more sensitive to the environment and allows for the preservation of open and natural areas.

B.    It promotes better site layout and energy efficient development.

C.    It promotes affordable and life-cycle housing.

D.    It promotes development intensities that match existing and proposed infrastructure investments.

5.2 General

5.2.1 Minimum Requirements

A.    Every building erected or moved and every plat submitted after the adoption of this article must be on a lot or building parcel that meets the minimum requirements of at least one lot permitted under this article, based on underlying zoning and subdivision type.

B.    Every building erected or moved and every lot shown on plat submitted after the effective date of this article must be on a lot or parcel with direct access on one of the following:

1.    A public street;

2.    An approved private street; or

3.    A public or private street via a public or private alley.

C.    All structures must be so located on lots or parcels as to provide safe and convenient access for servicing, fire protection, and the required on-site parking.

D.    No Building Permit, Zoning Development Permit or other development approval may be issued for a lot that does not meet the minimum lot area requirements of this LUC except as specified above and in the following cases:

1.    Nonconforming lots may be used in accordance with the provisions set forth in Section 1.10.8, Nonconforming lots.

2.    Telecommunications and utilities using land or an unoccupied building covering less than 1,000 square feet of site area shall be exempt from minimum lot area standards.

E.    The uses and density listed in this article are allowed by right unless otherwise expressly stated. Each project must comply with all of the applicable development standards of this article, all development standards of the base Zoning District and any Overlay District, if applicable, and any other applicable specific use standard(s) of this LUC.

F.    Remaining land not devoted to lots or public or private rights-of-way shall be dedicated as open space or common area in accordance with the requirements of Section 5.4.3A, Open Space and Common Area.

5.2.2 Housing Types

A.    Definitions

The following housing types are established to provide a common terminology for housing. All drawings are for illustrative purposes only.

Single Family Detached

A detached dwelling unit located on a single lot with private yards on all four sides

SF conventional plan

SF conventional

SF conventional2

Zero Lot Line House

A detached dwelling unit located on a single lot with private yards on three sides. The unit has a single side yard on one side comprising the equivalent of two side yards of a single-family detached house.

zero plan

Zero Lot Street

Zero Lot Street2

Alley-Loaded House

A detached dwelling unit located on a single lot with private yards on all four sides: however, the house is set closer to the street than a single-family detached house.

SF rear NEW PLAN

SF rear NEW2

SF rear NEW

Two-Family (Duplex) House

Two attached dwelling units in a single structure on a single lot (often called a duplex). The two units can be located on separate floors or side-by-side.

duplex-plan

duplex-front

duplex-rear

Townhouse

Two or more attached dwelling units located on separately owned lots or on a single lot where the units are lined up in a row and share side walls, individual units can be mixed vertically.

TH lane plan

TH lane1

TH lane2

Multi-family Dwelling

Three or more attached dwelling units in a single structure on a single lot. An apartment can vary in height from two to three stories; individual units can be mixed vertically.

apartment3

apartment

apartment2

Upper-Story Residential

A dwelling unit located on a floor above a nonresidential use.

livework plan

livework1

livework2

B.    Use-Specific Standards for the Respective Housing Types

The respective housing types shall comply with the applicable requirements of Section 3.2.1, Residential Use Standards, which are summarized as follows:

Use-specific Standards by Housing Type

Housing Type

Use-specific Standards

Single-family Detached

None

Alley-loaded Houses

Section 3.2.1A

Multifamily Dwellings

Section 3.2.1C

Two-family (Duplex) Dwellings

Section 3.2.1D

Townhouses

Section 3.2.1G

Manufactured Homes

Section 3.2.1H

Upper-story Residential

Section 3.2.1J

Zero Lot Line Houses

Section 3.2.1K

5.3 How to Use This Article

This article is divided into the following parts:

PART I. RESIDENTIAL DISTRICTS. This Part sets forth the standards for all types of residential subdivisions in all residential districts.

Section 5.4.1 to 5.4.2

PART II. NON-RESIDENTIAL DISTRICTS. This Part sets forth the standards for development in non-residential districts.

Section 5.5.1 to 5.5.3

5.4 Part I: Residential Districts

5.4.1 Residential Development Standards

Development projects may include a mix of housing types as set forth in Section 3.1, Use Table.

A.    Residential Density and Dimensional Standards

Residential development shall be subject to the maximum density and dimensional standards of the underlying base zoning district in accordance with the following table.

Residential Zoning Districts

Development Standard

MFR

SLR

LLR

RR

RG

Max. Density (units/acre)

8

5

2

1

0.20

Min. Project Boundary Buffer Parcel Size

5,445

8,712

21,780

21,780

21,780

Min. Front Yard and Street Side Yard

10’

20’

25’

25’

25’

Min. Interior Side Yard*

10’

10’

10’

15’

15’

Min. Rear Yard

10’

10’

20’

20’

20’

Min Lot Width*

80’

50’

100’

130’

130’

Bldg. Coverage Max.

55%

45%

25%

25%

25%

Max. Height Principal Structure

28’

28’

35’

35’

35’

Max. Height Accessory Structure

28’

28’

35’

35’

35’

*Side setback and min. lot width does not apply to townhome and multi-family shared walls.

B.    Project Boundary Buffer

1.    Project boundary buffers are intended to provide a suitable transition between the proposed subdivision and adjacent development. Buffers are required along all sides of the proposed subdivision that share a boundary with a protected zone district, excluding arterial or collector streets. For projects providing 20 percent or more affordable housing units as defined by Section 6.14, the project boundary buffer on each edge shall be 20 feet. For all other projects, the project boundary buffer on each edge shall be 20 feet or the proposed building height, whichever is greater.

2.    Buffer width shall be measured perpendicular to the property lines that define the project area.

3.    Development projects may include a mix of housing types as set forth in Section 3.1, Use Table, so long as the development complies with the maximum density requirement of the underlying base district (see subsection A of this section). [Ord. 549, 2016.]

C.    Mix of Housing Types

Two-family, townhouse, multi-family residential units may comprise no more than 50 percent of the total dwelling units of any proposed conventional residential subdivision. In no case shall the district density be exceeded for the overall site.

D.    Constrained Lands

1.    Maximum allowable density for constrained lands (or portion of property which constitutes constrained lands) as described in this subsection (below) in all subdivision types shall be reduced by a minimum of 50 percent (see also Section 5.6, Measurements, Computations, and Exceptions).

2.    Constrained lands include lands with natural slopes greater than 30 percent, jurisdictional wetlands, lands in the 100 year floodplain, public drinking water supply water sources (recharge areas for the aquifer in the Glen Canyon Formation), lands affected by unmitigable geo-hazards, and riparian habitats and archeological sites.

3.    Constrained lands in all developments and subdivisions shall be identified on plats and remain unoccupied by buildings or impervious surfaces, unless the applicant demonstrates to the County Council that this provision would constitute an unusual hardship and is counter to the purposes of this LUC. In cases where a hardship is granted not more than ten percent of any constrained land area shall be occupied by such surfaces.

E.    Land Suitability

The County shall not approve the subdivision of land if, from adequate investigations conducted by all public agencies concerned, it has been determined that in the best interest of the public, the site is not suitable for platting and development purposes of the kind proposed. Land deemed to be environmentally unsuitable shall not be platted for residential occupancy, or for such other uses as may increase danger to health, life, or property, or aggravate erosion or flood hazard. Such land within the plat shall be restricted for such uses as shall not be endangered by periodic or occasional inundation or shall not produce unsatisfactory living conditions.

5.5 Part II: Nonresidential Districts Revised 5/17

5.5.1 Nonresidential Dimensional Standards

The following lot design standards shall apply to all buildings and their lots in nonresidential districts. These standards shall also apply to mixed use buildings that combine non-residential and residential uses.

Nonresidential Zoning Districts

Development Standard

NC

GB

RC

RS

HC

LI

HI

Min. Lot Area

None

None

None

None

None

None

None

Min. Front Yard and Street Side Yard (ft.)

30’

10’

0’

50’

20’

15’

20’/300’

Min. Interior Side Yard (ft.)

10’

10’

10’

25’

10’

10’

50’/300’

Min. Rear Yard (ft.)

10’

10’

10’

25’

20’

10’

20’/300’

Mandatory Build-to Line (Percent)

--

--

70%

--

--

--

--

Min. Ground Floor Area/Unit (sf.)

--

--

--

--

--

--

--

Max. Height (ft.)

35’

35’

40’

24’

35’

35’

35’

5.5.2 Residential Development Standards in Nonresidential Districts

Development projects in nonresidential districts may include a mix of housing types as set forth in Section 3.1, Use Table, so long as the development complies with the maximum density requirement of the underlying base district (See Section 5.5.2B) and lot design standards of the underlying base district (See Section 5.5.3).

A.    Housing Types Permitted by District

Housing types permitted by district are as specified in Section 3.1, Use Table.

B.    Maximum Residential Density in Nonresidential District

Maximum allowed density in the respective nonresidential districts shall be as follows:

Maximum Density by District

Zoning Districts

Maximum Density

HC, Highway Commercial

18

GB, General Business

5

NC, Neighborhood Commercial

5

LI, Light industrial

5

RC, Resort Commercial

5

HI, Heavy industrial

1

RS, Resort Special

.20

5.5.3 Residential Dimensional Standards in Nonresidential districts

Maximum residential density in a nonresidential district is subject to the requirements of the underlying zoning district (in accordance with Section 5.5.2B). Residential development in nonresidential districts shall be subject to the dimensional standards provided in the following table.

Nonresidential Zoning Districts

Development Standard

*NC

*GB

RC

RS

HC

LI

HI

Min. Front Yard & Street Side Yard (ft.)

n/a

n/a

0

50

20

n/a

n/a

Min. Interior Side Yard (ft.)

n/a

n/a

10

25

10

n/a

n/a

Min. Rear Yard (ft.)

n/a

n/a

10

25

20

n/a

n/a

Min. Lot Width (ft.)

n/a

n/a

80

150

80

n/a

n/a

Max. Ht. Principal Structure (ft.)

35

35

24

24

35

n/a

n/a

*NC, GB, LI, and HI allow for mixed use, upper story residential only (see Section 5.5.1)

5.5.4 Project Boundary Buffer Revised 5/17

A.    Project boundary buffers are intended to provide a suitable transition between the proposed development and adjacent development. Buffers are required along all sides of the proposed development that share a boundary with a protected zone district pursuant to Section 6.10.1.A, excluding arterial or collector streets. For projects providing 20 percent or more affordable housing units as defined by Section 6.14, the project boundary buffer on each edge shall be 20 feet. For all other projects, the project boundary buffer on each edge shall be 20 feet or the proposed building height, whichever is greater.

B.    Buffer width shall be measured perpendicular to the property lines that define the project area.

C.    Development projects in nonresidential districts may include a mix of housing types as set forth in Section 3.1.1, Use Table, so long as the development complies with the maximum density requirement of the underlying base district (See Sections 5.5.1 and 5.5.2B).

[Ord. 559, 2017.]

5.6 Measurements, Computations and Exceptions

5.6.1 Gross Density

Gross density means the number of dwelling units for each acre of land and which is calculated by dividing the total number of dwelling units in a development by the total acreage of the lots on which the development is located.

A.    Upper-Story Residential Exemptions

The maximum gross density provisions of the LUC shall not be interpreted as requiring land area for upper-story residential units in nonresidential structures. Such units are exempt from the maximum gross density calculation.

5.6.2 Lot Area

Lot area refers to the amount of horizontal land area within lot lines. No building permit or development approval shall be issued for a lot that does not meet the minimum lot size requirements of this LUC, with the following exceptions:

A.    Lot Area Reduction for Public Purpose

When an existing lot is reduced as a result of conveyance to a federal, state or local government for a public purpose and the remaining area is at least three-quarters of the required minimum lot size for the district in which it is located, the remaining lot shall be deemed to be in compliance with the minimum lot size standards of this LUC.

B.    Utility Facilities

Utility facilities using land or an unoccupied building requiring less than 1,000 square feet of site area are exempt from the minimum lot size requirements of all districts.

5.6.3 Required Yards (Setbacks)

Setback refers to the unobstructed, unoccupied open space between a structure and the property line of the lot on which the structure is located. Setbacks shall be unobstructed from the ground to the sky and measured as the horizontal distance between a property line and the furthermost projection of the structure, except as provided otherwise in this LUC.

A.    Front Yard Setback

1.    Corner lots

For lots with frontage on 2 intersecting streets, such a lot shall be considered to have 2 front lot lines and shall comply with front yard setbacks from each front lot line.

2.    Double Frontage Lots

Where lots have double frontage, running through from one street to another, a required front yard shall be provided on both streets.

3.    Setback Averaging

If the existing front setbacks of lots within the same zoning district and fronting on the same side of the street are less than the required front setback of the underlying zoning district, applicants shall be allowed to use the “average” front setback on the block. In such cases, the “average setback” shall represent the mean (average) setback of all lots on the same side of the street within 150 feet of the subject lot, provided that lots that are not developed with the same type of use that is proposed on the subject property shall not be included in the calculation. When one (1) or more of the lots on the block are vacant the normally required setback for the vacant lot shall be used in calculating the average setback. This provision shall not be interpreted as requiring a greater front setback than imposed by the underlying zone district. Responsibility for demonstrating eligibility for an “average setback” pursuant to this subsection shall be the sole responsibility of the applicant.

4.    Mandatory Build-to Line

Build-to line refers to the percent of the primary building façade required to be built within 5 feet of the otherwise applicable front or street yard setback along the primary street(s) adjacent to the lot.

B.    Garage Setbacks

1.    Garages, carports, and similar vehicle storage facilities entered from a front or side street and facing thereto shall be set back a minimum of 5 feet further from the street than the principal structure, whichever is more; provided however that this requirement shall not apply to lots on cul-de-sacs.

2.    Garages, carports, and similar vehicle storage facilities entered and accessed from an alley may be reduced to 5 feet.

C.    Non-Residential Buildings

No rear yard shall be required for non-residential buildings if an alley is located adjacent to the rear lot line.

5.6.4 Average Lot Width

E.    Measurement

1.    Lot width shall be the distance between the 2 side lot lines measured 30 feet back from the front lot line.

2.    Average lot width shall be the average lot width of all lots in a given filing or shown on any plat.

F.    Cul-De-Sacs

Notwithstanding any other provisions of this LUC, lots fronting on a cul-de-sac shall have a minimum front street line of 30 feet and a minimum lot width of 40 feet.

5.6.5 Maximum Height

A.    Measurement

1.    Buildings

Building height shall be determined by measuring the vertical distance between the lowest point where the wall face of the building intersects finished grade around the perimeter of the building (or structure other than fences, and telecommunications and microwave towers and antennas) and the highest point on the building.

2.    Telecommunications and Microwave Towers and Antennas

Height of telecommunications and microwave towers and antennas shall be determined by measuring the vertical distance from the lowest point of intersection with the natural grade to the highest point of the tower, including all antennas, other attachments, or structures, when towers are mounted upon other structures.

3.    Accessory Uses

Maximum height of accessory structures shall not exceed 24 feet.

4.    Fences and Walls

Height of fences or walls shall be measured as the vertical distance between finished grade on the highest side of the fence or wall to the top of the fence or wall.

5.    Permitted Exceptions

a.    The following structures and features may exceed the otherwise allowable maximum height by up to 25 percent:

(1)    Chimneys, smokestacks or flues;

(2)    Cooling towers and ventilators;

(3)    Elevator bulkheads and stairway enclosures;

(4)    Tanks and water towers;

(5)    Utility poles and support structures;

(6)    Belfries, spires and church steeples; and

(7)    Monuments and flag poles.

b.    Finished grades associated with underground garages and ramps accessing underground garages shall not be considered as part of height measurement and calculation.

B.    Building Coverage

1.    Measurement

The maximum area of the lot that is permitted to be covered by buildings, including both principal structures and accessory buildings.

2.    Permitted Exceptions

Building coverage does not include paved areas such as driveways, uncovered porches or patios, decks, open swimming pools, or roof overhangs of less than 2 feet.

C.    Gross Floor Area

1.    Gross floor area shall be determined by the sum of the areas of the floors of a building or structure, including areas used for human occupancy or required for the conduct of the business or use, as measured from the exterior faces of the walls. Gross floor area shall not include basements, unenclosed porches, or attics when not used for human occupancy, nor any floor space in an accessory building, carport, or the main building intended or designed for the parking of motor vehicles in order to meet the County parking requirements, arcades, porticoes, and similar open areas which are located at or near street level, which are accessible to the general public, and which are not designed or used as occupancy, sales, display, storage, service, or production areas.

2.    Basement shall be that portion of a building which is wholly or partly below grade, the ceiling of which is less than four feet above grade.

5.6.6 Steep Slopes

Slope shall be determined on an individual development basis before any site clearing, excavation, or grading for the purpose of calculating constrained lands.

A.    Measurement

1.    Scale

Contour maps and slope calculations shall be prepared and certified by a licensed professional engineer or surveyor showing contours at intervals no greater than 5 feet, drawn at a scale of one inch equals two hundred feet maximum.

2.    Calculation

Slopes shall be calculated in horizontal intervals no greater than 50 feet. Small islands, outcrops, and peninsulas having slopes distinctly different from surrounding property may be excluded from slope determination if, in the opinion of the Planning Commission, the exclusion of such areas will not be contrary to the overall purposes of steep slope protection.

B.    Verification

Field surveys may be required of the applicant by the county engineer to verify the accuracy of the contour lines shown on the contour map.