Chapter 18.25
R-H RESIDENTIAL HILLSIDE
Sections:
18.25.040 Designation of slope hazard area.
18.25.050 Permitted uses and structures.
18.25.060 Conditional uses and structures.
18.25.070 Dimensional standards.
18.25.090 Site capacity calculation.
18.25.100 Development standards and review criteria.
18.25.010 Purpose.
To serve as a low density residential district which is similar to the purpose and intent of the R-1 district but where it is recognized that densities should vary according to location and topography. [Ord. 508 § 3.01.0, 1982].
18.25.020 Intent.
The intent of the residential hillside district is to maintain and enhance the visual and physical identity of the hills as well as native geologic conditions and to identify areas of potential natural hazards due to soil conditions and/or slope. [Ord. 508 § 3.01.1, 1982].
18.25.030 Objective.
The approach set forth in the residential hillside district regulations takes a larger than lot-by-lot perspective in regulating environmental degradation. The objective is to permit maximum development while, at the same time, protecting resources by requiring a site capacity rather than a lot capacity analysis of developmental constraints. The site capacity calculation uses the open space ratio as a standard to ensure protection of the natural environment in a dependable and consistent fashion. In addition, developmental limits are specified on a resource-by-resource basis. For example, no disturbance of a very unstable or rare resource is permitted, whereas some level of disturbance of a less sensitive feature may be allowed. In summation, the residential hillside district regulations endeavor to:
(1) Provide site and design standards intended to minimize impacts in hazardous areas;
(2) Provide review procedures intended to preserve the environmental quality of the area; and
(3) Encourage clustered development and a variety of housing types to better utilize lands with topographic constraints. [Ord. 508 § 3.01.2, 1982].
18.25.040 Designation of slope hazard area.
(1) Properties classified as residential hillside by the provisions of this title are recognized as containing areas where slope may be a development factor. The soil series survey and the topography information compiled for the natural features element of the comprehensive plan (support document) and records of known steep slopes are the basis for establishing the R-H district boundaries. Because the general mapping and studies prepared for the comprehensive plan are not intended for development purposes, detailed information for individual parcels or ownerships shall be submitted with each application for development.
(2) The city engineer is hereby designated to review all applications for development in the R-H district to identify the slope hazard and to determine the acreage of land with development constraints to implement the site capacity calculation of MCMC 18.25.090. The city engineer shall have the authority to require a site investigation report (as described in MCMC 18.150.040) to be submitted with an application when, in his professional judgment, the site contains areas of potential hazard likely to be affected by the proposed development, except that a site investigation report is specifically required for all building sites containing areas of greater than 25 percent slope or identified mass movement hazard areas.
(3) The initial review of an application may provide information calling for an adjustment of the R-H district boundaries for an individual parcel. Property which is zoned R-H, but where slope does not appear to be a development factor, may be corrected legislatively to R-1 (as provided by MCMC 18.20.040(1)) if all of the following circumstances exist:
(a) All slopes within the building construction site are less than 12 percent;
(b) The natural development constraints listed in Step 2 of MCMC 18.25.090 total less than six percent of the site area; and
(c) The property is contiguous to an R-1 district or consists of five or more contiguous acres. [Ord. 508 § 3.01.3, 1982].
18.25.050 Permitted uses and structures.
The following uses and structures and similar uses and structures are permitted outright upon site review approval:
(1) Dwelling, single-family.
(2) Residential home.
(3) All uses and structures customarily accessory to permitted uses subject to the “limitations and exceptions” set forth in Chapter 18.75 MCMC. [Ord. 508 § 3.01.4, 1982].
18.25.060 Conditional uses and structures.
The following uses and structures and similar uses and structures may be permitted as a conditional use subject to the procedures of Chapter 18.170 MCMC, whereupon, (1) a conditional use permit may be granted when the criteria for approval are met or can be met by observance of conditions; or (2) a conditional use permit may be denied if the findings of fact conclude that the permit criteria cannot be met:
(1) Child day care facilities (see MCMC 18.75.050).
(2) Church.
(3) Community building.
(4) Duplex.
(5) Home instruction classes (see MCMC 18.75.060).
(6) Planned development/residential (subject to the approval criteria set forth in Chapter 18.130 MCMC).
(7) Preschool/kindergarten/nursery school. [Ord. 508 § 3.01.5, 1982].
18.25.070 Dimensional standards.
(1) Lot Requirements.
(a) In the residential hillside district the minimum lot size shall be determined by the site capacity calculation as described in MCMC 18.25.090 and the site investigation as described in MCMC 18.150.040, but shall not be less than the size requirements specified in subsections (1)(b) through (e) of this section.
(b) Lot size shall be a minimum of 5,400 square feet.
(c) The width of the lot at the building line shall be not less than 60 feet.
(d) The depth of the lot shall be not less than 90 feet.
(e) The maximum lot coverage shall be 40 percent.
(2) Yard Setback Requirements (See MCMC 18.145.010).
(a) The minimum front yard setback shall be 20 feet.
(b) The minimum interior side yard setback shall be five feet; however, the minimum shall be increased by one-half foot for every one foot of home height over 18 feet, not to exceed a minimum side yard setback of 10 feet.
(c) The exterior side yard abutting a street shall have a minimum side yard setback of 15 feet.
(d) The minimum rear yard setback shall be 15 feet.
(3) Building Height (See Chapter 18.145 MCMC for Exceptions).
(a) Except as provided by subsection (3)(b) of this section, no main building shall exceed a height of 35 feet and no accessory building shall exceed a height of 20 feet.
(b) Where building height will obscure vision from the main floor of other buildings in the area, the maximum building height shall be 20 feet or as otherwise designated by the planning commission in order to retain visibility from windows facing the front yard for a minimum of 45 degrees in each direction. The provisions of this subsection do not apply to the relationship between buildings that are all part of a single development. [Ord. 841 § 1 (Exh. A), 2021; Ord. 508 § 3.01.6, 1982].
18.25.080 Density factor.
Elsewhere in this title, residential land use intensity is expressed as “gross density” or “number of units per gross acre”; the regulations of the R-H district are based on the use of a “density factor” which applies only to buildable land and results in a determination of site capacity. Therefore, the intensity of use of any piece of buildable land within the district is held constant, although the gross density may vary depending on the characteristics of the individual property. The reason for this is that the “gross density” cannot accommodate variations in the physical site. The “density factor” is a direct measurement of the impact of a given development on road systems, community facilities, schools and services. The residential hillside “maximum density factor” is 6.88. This is comparable to a “gross density” of four units per acre when calculated for a site which is free of development constraints. [Ord. 508 § 3.01.7, 1982].
18.25.090 Site capacity calculation.
The site capacity for any proposed development is equal to the net buildable area of the site multiplied by the density factor. The site capacity calculation provides the mechanism for subtracting from the base site area all portions of a site inappropriate for development to determine the extent to which a site may be utilized, given its unique physical characteristics. The following four steps are utilized to calculate the site capacity. The totals of Steps 1, 2 and 3 are used to determine the net buildable site area, which is then multiplied by the density factor to determine the number of units permitted (Step 4).
(1) Step 1 – Base Site Area. Certain portions of a tract may not be useable for the activity proposed for the site. These are subtracted from the total acreage involved to determine base site area, as follows:
|
(a) Gross site as determined by actual on-site survey: |
______ Acres |
|
(b) Subtract land constituting roads and land within existing or required right-of-way for streets and rights-of-way or easements for utilities. (Does not include any future internal roads or utility easements which may ultimately serve the proposed development.) |
______ Acres |
|
(c) Subtract land which is not contiguous, or is cut off in such a way that common use is hindered or that the land is unavailable for building purposes or is land that will be calculated separately. (Such as a separate parcel which does not abut, adjoin or share common boundaries with the rest of the development or land which is cut off from the main parcel by road, railroad, existing land uses or major stream.) |
______ Acres |
|
(d) Subtract land which is proposed for nonresidential use: |
______ Acres |
|
(e) Equals base site area: |
______ Acres |
(2) Step 2 – Protected Land. All land area consisting of the natural development constraints listed below shall be mapped and measured. The total acreage of each feature shall be multiplied by its respective open space ratio to determine the amount of land to be kept in open space in order to protect the feature. The sum total of all land on the site to be protected from development equals total protected land, and is calculated as shown in MCMC Table 18.25.090.
|
COLUMN A |
COLUMN B |
COLUMN C |
COLUMN D |
|---|---|---|---|
|
Natural Development Constraints* |
Open Space Ratio |
Area of Land Involved** |
Protected Land* (Acres in Column C x Open Space Ratio) |
|
Steep Slopes (12% to 15%) |
0.60 |
______________ |
______________ |
|
Steep Slopes (16% to 25%) |
0.70 |
______________ |
______________ |
|
Steep Slopes (16% to 25%) plus poor soil suitability*** |
0.80 |
______________ |
______________ |
|
Steep Slopes (greater than 25%) |
0.95 |
______________ |
______________ |
|
Very Poor Soil Suitability*** |
0.95 |
______________ |
______________ |
|
Erosion Hazard Area |
1.00 |
______________ |
______________ |
|
Bluffs |
1.00 |
______________ |
______________ |
|
Ravines |
0.98 |
______________ |
______________ |
|
Ravine Buffers |
0.80 |
______________ |
______________ |
|
Ponds or Watercourse |
1.00 |
______________ |
______________ |
|
Drainage Ways |
0.50 |
______________ |
______________ |
|
TOTAL LAND IN NATURAL FEATURE: |
_______ Acres |
||
|
TOTAL PROTECTED LAND: |
_______ Acres |
||
* MCMC 18.160.010 through 18.160.070 detail how development of such natural features shall be restricted. See Chapter 18.10 MCMC for a definition of each feature.
** This total is the actual acres involved. Do not use the land area more than once. For example, if there is land containing two of the features listed, the feature with the greater open space ratio shall be used.
*** See “Soils Information Chart,” Myrtle Creek Comprehensive Plan; Support Document, Natural Features Element.
(3) Step 3 – Recreation/Common Land. When it is required by this title or MCMC Title 17 or as a condition of approval that a certain amount of land be set aside for park purposes, recreation areas, common land or other open space purposes, this calculation provides guidelines to ensure that a minimum amount of land not restricted by the two previous steps is retained for such purposes. (Exception: Residential sites which would be required to provide less than one-quarter acre by the following calculation are exempted from Step 3 and sum total of zero shall be used.) Total recreation land is calculated as follows:
|
Take: |
Base Site Area (Step 1 Total): |
______ Acres |
|
Subtract: |
Total acres of land in natural feature (Step 2, Column C) |
– ______ Acres |
|
Equals: |
TOTAL UNRESTRICTED LAND: |
= ______ Acres |
|
Multiply: |
Above total by 6%: |
x 6% |
|
Equals: |
Total recreation land required: |
= ______ Acres |
|
Subtract: |
Any protected land which will be improved for recreation |
– ______ Acres |
|
Equals: |
TOTAL RECREATION LAND REMAINING TO BE PROVIDED: |
= ______ Acres |
(4) Step 4 – Determination of Site Capacity. Individual site capacity is determined by calculating the net buildable site area. The number of dwelling units permitted is determined by multiplying the density factor by the net buildable site area. The calculations are as follows:
|
Take: |
Total protected land (Step 2, Column D): |
______ Acres |
|
Add: |
Total recreation land remaining to be provided (Step 3 Total) |
+ ______ Acres |
|
Equals: |
TOTAL OPEN SPACE: |
= ______ Acres |
|
Take: |
Base Site Area (Step 1 Total): |
______ Acres |
|
Multiply: |
By Open Space Ratio (40%): |
x 40% |
|
Equals: |
MINIMUM REQUIRED OPEN SPACE: |
= ______ Acres |
|
Take: |
Base Site Area (Step 1 Total): |
______ Acres |
|
Subtract: |
Total Open Space (from above), or |
|
|
|
Minimum Required Open Space (whichever is greater): |
– ______ Acres |
|
Equals: |
NET BUILDABLE SITE AREA: |
= ______ Acres |
|
Take: |
Net Buildable Site Area (above): |
______ Acres |
|
Multiply: |
By maximum density factor (6.88): |
x 6.88 |
|
Equals: |
NUMBER OF DWELLING UNITS PERMITTED: (Do not round off; use lower whole number) |
= ______ Units |
[Ord. 508 § 3.01.8, 1982].
18.25.100 Development standards and review criteria.
Notwithstanding the conditional use provisions of MCMC 18.25.060, any project involving the erection of a new building or structure, the enlargement in height or ground coverage, or the intensification of use of any building or structure shall:
(1) Be reviewed in accordance with the site review criteria contained in Chapter 18.150 MCMC. The planning commission or city administrator or the city administrator’s designee shall conduct the site review for all such development in the R-H district except for projects involving the construction of a single-family/detached dwelling located on a single parcel, which will be reviewed by the planning department;
(2) Provide improvements and comply with the design standards applicable to the type of development proposed as set forth in Chapter 18.150 MCMC; and
(3) Provide off-street parking as set forth in Chapter 18.90 MCMC. [Ord. 508 § 3.01.9, 1982].