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

A. Purpose. Solar standards are utilized to create lot divisions, layouts and building configurations to help preserve access to sunlight to one- and two-unit dwellings.

B. Solar Lot Standards.

1. Applicability. Solar lot standards apply to the creation of lots within subdivisions in RS and RM Zones.

2. Solar Lot Requirements. In RS and RM Zones, at least 70 percent of the lots in a subdivision shall have a minimum north-south lot dimension of 80 feet or more.

3. Exceptions to the Solar Lot Requirements. A proposed subdivision shall qualify for an exception to subsection (B)(2) of this section if one or more of the following development constraints are present:

a. Compliance with applicable street standards or public street plans requires a street configuration that prevents the lot from being oriented for solar access.

b. An existing public easement or right-of-way prevents the lot from being oriented for solar access.

c. There is a significant natural feature on the site that will continue to exist after the site is developed, and that prevents the lot from being oriented for solar access.

4. Exemptions to the Solar Lot Requirements. A proposed lot shall not be identified as a “solar lot” but shall be counted as a lot that satisfies subsection (B)(2) of this section when the lot satisfies subsection (B)(4)(a), (b), (c) or (d) of this section.

a. Slopes. The lot has an average slope of 15 percent or more in a direction greater than 45 degrees east or west of true south.

b. Existing Off-Site Shade. The lot is within the shadow pattern of off-site features, such as but not limited to buildings, topography, or coniferous trees or broadleaf evergreens, which will remain after development occurs on the site from which the shade is originating.

i. Shade from existing or approved off-site buildings or structures and from topographic features is assumed to remain after development of the site.

ii. Shade from vacant developable areas off site is assumed to be the shadow pattern that would result from the largest building allowed at the closest setback allowed on adjoining land, whether or not that building now exists.

iii. Shade from coniferous trees or broadleaf evergreens is assumed to remain after development of the site if that vegetation is situated in a required setback; or part of a developed area, public park, or legally reserved open space; or part of landscaping or other features required pursuant to this code.

c. Existing On-Site Shade. The site, or portion of the site for which the exemption is sought, complies with at least one of the following:

i. The site is within the shadow pattern of on-site features such as, but not limited to, buildings and topography which will remain after the development occurs.

ii. The site contains coniferous trees or broadleaf evergreens at least 30 feet tall and more than eight inches in diameter measured four feet above the ground which have a crown cover over at least 80 percent of the site or relevant portion. The applicant can show such crown cover exists using a scaled survey or an aerial photograph. If granted, the exemption shall be approved subject to the condition that the applicant shall preserve at least 50 percent of the nonsolar friendly vegetation that causes the shade that warrants the exemption. The applicant shall file a note on the plat or documents in the office of the County Recorder binding the applicant to comply with this requirement.

d. Housing Mix. The lot is designated for a housing type other than single-unit detached dwellings in a proposed subdivision that identifies at least 10 percent of the lots for a housing type other than single-unit detached dwellings.

C. Solar Setback Standards.

1. Applicability. These standards apply to all structures on RS and RM zoned lots, 5,000 square feet or greater, with a minimum north-south lot dimension of 80 feet.

2. Solar Setback Requirements. Buildings shall be set back from the northern property line according to the standards in this section. When a northern property line abuts an alley, street, or common area, the setback will be measured to the next lot line across the alley, street, or common area. An applicant for a development permit for a building subject to this section shall submit documentation that shows either the solar setback or how the structure qualifies for an exemption. If buildings on separate lots are attached or connected at a common lot line, the solar setback standards apply as if the buildings are a single building on a single lot composed of both lots.

a. Solar Setback for RS Zone. The solar setback of the shade point shall be greater than or equal to the following formula:

SSB =

(2.5 X SPH) + (N divided by 2) – 85

Where:

SSB =

Solar setback (the shortest horizontal distance between the shade point and the plane of the northern lot line).

SPH =

Shade point height (reduce this dimension by three feet if the shade point is a ridgeline between 45 degrees east or west of true north).

N =

North-south lot dimension. Maximum allowable “N” for purposes of calculating the solar setback shall be 90 feet.

The following table, which accurately applies the formula, can be used to determine compliance with the solar setback standard.

Table 3.5.400.A. Solar Setback from Northern Lot Line for RS Zone [SSB]

(All figures are in feet.)*

Shade Point Height* [SPH]

North-South Lot Dimension

90 feet [N]

85 feet [N]

80 feet [N]

18 feet

5

2.5

0

20 feet

10

7.5

5

22 feet

15

12.5

10

24 feet

20

17.5

15

26 feet

25

22.5

20

28 feet

30

27.5

25

30 feet

35

32.5

30

*Solar setback and shade point height are usually measured from an eave or from a ridge line of a roof. See Figure 3.5.400, Measuring Shade Point Height.

b. Solar Setback for RM Zone. The solar setback of the shade point shall be greater than or equal to the following formula:

SSB =

(2.5 X SPH) + (N divided by 2) – 100

Where:

SSB =

Solar setback (the shortest horizontal distance between the shade point and the plane of the northern lot line).

SPH =

Shade point height (reduce this dimension by 3 feet if the shade point is a ridgeline between 45 degrees east or west of true north).

N =

North-south lot dimension. Maximum allowable “N” for purposes of calculating the solar setback shall be 90 feet.

The following table, which accurately applies the formula, can be used to determine compliance with the solar setback standard.

Table 3.5.400.B. Solar Setback from Northern Lot Line for RM Zone [SSB]

(All figures are in feet.)*

Shade Point Height* [SPH]

North-South Lot Dimension

90 feet [N]

85 feet [N]

80 feet [N]

24 feet

5

2.5

0

26 feet

10

7.5

5

28 feet

15

12.5

10

30 feet

20

17.5

15

32 feet

25

22.5

20

34 feet

30

27.5

25

36 feet

35

32.5

30

*Solar setback and shade point height are usually measured from an eave or from a ridge line of a roof. See Figure 3.5.400, Measuring Shade Point Height.

Figure 3.5.400. Measuring Shade Point Height

3. Exemptions to Solar Setback Requirements. A building is exempt from the solar setback standards when any of the following conditions exist:

a. Slopes. The lot on which the building is located has an average slope of 15 percent or more in a direction greater than 45 degrees east or west of true north.

b. Existing Shade. The building will shade an area that is already completely shaded by one or more of the following:

i. An existing or approved building or structure.

ii. A topographic feature.

iii. Coniferous trees or broadleaf evergreens that will remain after development of the site.

c. Insignificant Benefit. The building will shade one or more of the following:

i. A nondevelopable area, such as designated open space, a public utility easement, street or alley.

ii. The wall of an unheated space, such as a garage, excluding solar greenhouses and other similar solar structures.

iii. The wall of a nonresidential structure.

iv. No more than 20 percent of a south wall of an existing habitable dwelling.

d. Master Planned Development Exemption. The lot is identified as being exempt from solar setback provisions through an approved Master Planned Development application where one or more of the following exists:

i. The lot has been identified as being exempt from solar setback standards.

ii. The proposed building locations and heights were approved. [Ord. NS-2423, 2021; Ord. NS-2137, 2009; Ord. NS-2016, 2006]