The purpose of these regulations is to promote the public health, safety, and general welfare by using the following criteria for building design:
A. In the RA, RS-1, and RS-2 zoning districts, buildings on natural topography greater than twenty percent (20%) slope shall be designed in a manner to reduce visibility by using stepped building forms, natural colors and materials, sloped roofs, and landscaping, and shall use a combination of these techniques such that the building does not skyline. Skylining is defined in 9-1C-1 as "an outline of a structure against the background of the sky" and occurs when a structure is sited near or atop the crest of a ridge, knoll, saddle, or summit.
B. In the RM-1, RM-2, SC, CC, REC, and PI zoning districts, buildings on natural topography greater than fifteen percent (15%) slope shall be designed in a manner to reduce visibility by using stepped building forms, natural colors and materials, sloped roofs, and landscaping, and shall use a combination of these techniques such that the building does not skyline. Skylining is defined in 9-1C-1 as "an outline of a structure against the background of the sky" and occurs when a structure is sited near or atop the crest of a ridge, knoll, saddle, or summit.
C. For any buildable lot of record without a platted building envelope, no structure may be built on a record grade of over fifteen percent (15%) slope if there is adequate area available for development below the fifteen percent (15%) slope line. Note: The city recognizes only platted building envelopes, but recorded building envelopes may exist in a private party agreement. The recorded building envelope is not a substitute for a platted envelope.
D. No structure may be built on a record grade of over twenty five percent (25%) slope except as provided in subsection E of this section. Where subsection E is not applicable, if evidence acceptable to the city is provided by the applicant showing that strict enforcement of this provision would prohibit a substantial portion of permitted or conditional uses of the property then the applicant may apply for a variance in accordance with Chapter 5, Article B, of this title. All other provisions of the hillside development regulations shall remain in effect.
E. The allowances provided in this section are not by-right entitlements and depend on the Director or Commission making findings that the development has been designed in a manner that will not create a visual concern, or physical dominance that would unreasonably negatively impact views, as well as findings that all other applicable standards of Sun Valley Municipal Code are met. The allowances provided in this section are in no way intended to be a means to permit development to be located further upslope on a development site than would otherwise be permitted.
In the following limited circumstances structures are permitted to make minor encroachments into record grade over twenty five percent (25%) slope without receiving a variance through section 9-5B-8 of this title:
1. Areas of slope greater than twenty five percent (25%) that are located entirely within an existing, platted building envelope and site areas related to rotated and expanded building envelopes where building footprints are permitted to be located in accordance with 9-2A-3-I-1-b.
a. This provision is not intended to allow a substantial portion of the one-third (1/3) of a structure's footprint that is permitted to be located outside of the envelope in accordance with 9-2A-3-I-1-a to be located upslope of the platted building envelope.
2. Isolated areas of slope greater than twenty five percent (25%) located outside of an existing, platted building envelope, including circumstances where no platted building envelope exists, that are insignificant in size.
3. The toe of substantial areas of slope greater than twenty-five percent (25%) when such encroachment is reasonably unavoidable due to considerable site constraints including, but not limited to, limited lot depth, providing driveway access to the lot, regulations contained within Article I. Flood Hazard Protection and Article J. Riparian Zones, or the presence of wetlands identified in a site-specific wetlands inventory completed within the past 365 days.
a. This provision is not intended to allow a substantial portion of the one-third (1/3) of a structure's footprint that is permitted to be located outside of the envelope in accordance with 9-2A-3 I.1.a. to be located upslope of the platted building envelope.
4. Retaining walls required by Title 7, Engineering Standards and Design Practices.
5. Other circumstances not described above where the Community Development Director, when reviewing administrative applications, or the Planning and Zoning Commission, when reviewing applications requiring a public hearing, make a Finding of Fact that the encroachment into record grade slope greater than twenty five percent (25%) is de minimis.
a. For the purpose of interpreting this ordinance, de minimis shall mean lacking significance or importance; so minor as to merit disregard. A finding of de minimis encroachment shall consider criteria including the square footage of the encroachment relative to the size of the structure and the subject property, the slope of the adjacent existing grade and adjacent proposed finished grade, height of the portion of the structure making the encroachment relative to the maximum height of the structure and the maximum height permitted in the zoning district, and the visibility of the encroachment from adjacent properties and adjacent streets, trails, or public lands.
6. Structures east of Sun Valley Road, within one thousand five hundred feet (1,500'), and south of Dollar Road, may be built on a record grade of over twenty five percent (25%) slope subject to the applicable regulations of the respective zoning district for each property, and subject to the evaluation standards of article A of this chapter. Encroachments into record grade slopes over twenty five percent (25%) are permitted because the ravine of Trail Creek does not present visual concerns or physical dominance on the city's landscape.
7. Existing platted lots containing significant downhill sloping terrain as primarily accessed from above. (Ord. 428, 7-15-2010; amd. Ord. 558, 12-2-2021)