A. Program Outline: Specific areas in the Washington Fields area and some of the area north of I-15 have been designated as bonus density areas on the general plan land use map to provide incentives that will help preserve open space. These areas are allowed a base density of one dwelling unit per acre, which corresponds to the RA-1 zone. However, bonus density credits may be given as multiples of the base density for specific open space amenities (outlined below) that are incorporated into developments and are beneficial to the public. If higher density zoning is present at the time of subdivision or rezoning, credits are reduced proportionally. If all of the credits were to be granted, a property could theoretically achieve a density of three and five-tenths plus (3.5+) units per acre (2.5 plus units per acre in bonus density, plus the original 1 unit per acre in base density). However, it is unlikely that all of the density bonus categories could or would be earned on a given parcel (e.g., it is not desirable to have a public park on every parcel), plus there must be a density cap to meet the intent of the general plan. Therefore, the actual density increases resulting will average close to the two and five-tenths (2.5) units per acre identified as a goal in the general plan.
B. Program Participation: If the property is already zoned RA-1, then an applicant may simply propose a subdivision that meets the RA-1 zone development standards. If the applicant wants to participate in the bonus density program, a development agreement may be proposed that incorporates the open space amenities for the bonus density credits, along with a proposed subdivision. If the property has a zoning designation that is less dense than the RA-1 zone, then a zone change request to RA-1 must first be approved by the city council after a recommendation by the planning commission. If the applicant wants to participate in the bonus density program, a development agreement may be proposed along with the zone change request, or the applicant may wait until the RA-1 zone is approved and then propose a development agreement along with a proposed subdivision. If the applicant does not want to participate in the bonus density program, then a proposed subdivision must meet the RA-1 zone development standards. If the property has a zoning designation that is more dense than the RA-1 zone and an applicant wants to participate in the bonus density program, density credits will be proportionally reduced and identified in a development agreement.
C. Modified Area, Width And Yard Regulations: Since the purpose of the bonus density program is to help preserve open space, lots in a subdivision may be clustered and the areas of the lots may be reduced. As lots are reduced in size, their widths and minimum yard setbacks must also be proportionally reduced in size. Lot setbacks must be noted on the final plat of each subdivision. The following table outlines the modified area, width and yard regulations for lots when an applicant participates in the bonus density program:
1. The absolute minimum lot size is 6,000 square feet. The smallest lots of a subdivision are to be internal to the project, and the lot sizes along the subdivision boundaries are to be within a single density transition category of adjacent properties.
2. Unlike the minimum yard setbacks, the lot widths are more of a general guideline than a minimum standard. The intent is for the lot widths to be proportional to the corresponding lot size range. It is undesirable to have lots extremely narrow compared to their depths. Each proposed subdivision will be evaluated to see if this intent is being met. Flag lots may also be considered for properties that have irregular shapes and/or topography.
D. Open Space Amenities And Bonus Density Credits:
1. Interconnectivity Of Internal Streets: Streets connect to each other within the project to create an informal grid that provides multiple routes for emergency vehicles and distributes traffic evenly through a neighborhood. To qualify for this density bonus, no more than twenty percent (20%) of the lots shall be located on cul-de- sacs.
Credit: Twenty five percent (25%) increase in density.
2. Interconnectivity Of External Streets: Streets connect to adjoining parcels/subdivisions to create an informal grid that provides multiple routes for emergency vehicles and distributes traffic evenly through a subarea. To qualify for this density bonus, access streets in addition to what is already required (the basic minimum number of access streets for each subdivision is 2, but larger subdivisions or subdivisions that have specific access and/or circulation issues may require more than 2 access streets), shall be provided, and the additional connecting streets provided shall be stubbed internal to adjacent properties and not perpendicular to streets external to the development.
Credit: Fifteen percent (15%) increase in density for one additional street.
Twenty five percent (25%) increase in density for more than one additional street.
3. Houses Facing Onto Arterial And Major Collector Streets: It is acknowledged that major and minor arterial streets (106 foot and 80 foot rights of way) and major collector streets (66 foot rights of way) are designed to optimize for traffic capacity and speed. Residential lots may be allowed to back (double frontage lots) onto arterial and major collector streets as long as there are adequate setbacks and landscape screening. Additionally, residential streets (60 foot and 50 foot rights of way) are intended to optimize for convenient travel, safe mixing of pedestrians and vehicles, and to be attractive settings for homes. Accordingly, double frontage lots are not allowed (except in cases of topographical constraints and factors relating to safety) along residential streets. It is possible to front homes onto arterial and major collector streets through the use of rear alleys or frontage roads. To qualify for this density bonus, double frontage lots are not allowed on streets classified as arterials (106 foot and 80 foot rights of way) and major collectors (66 foot rights of way). Keep in mind that intersection spacing must meet city standards for alleys and frontage roads as well as all other streets.
(Note: Except in cases of topographical constraints and factors relating to safety, and if it makes no difference to traffic impacts, double frontage lots are prohibited along rights of way less than 66 feet.)
Credit: Twenty five percent (25%) increase in density.
4. Mix Of Lot Sizes: Consistent with the general plan, the objective of this incentive is to encourage developments that have a mix of lot sizes so as to create a varied appearance (avoiding "cookie cutter" character). To qualify for this density bonus, credit is given for distinct variations in lot sizes.
Credit: Five percent (5%) increase in density for each variation of lot size that pertains to at least ten percent (10%) of the lots (a variation is a change of at least 25 percent in lot size), up to a maximum of twenty five percent (25%). To qualify for this density bonus, no more than fifty percent (50%) of the area may be within one size range (±12.5 percent constitutes a size range).
5. Neighborhood Park Land Dedication: Through the general plan, the city has adopted a neighborhood park level of service (LOS) standard of six (6) acres of park for every one thousand (1,000) population. In circumstances where a development does not actually generate a need for at least a four (4) acre park (minimum size for efficient city maintenance), this density bonus provides an incentive to dedicate additional park land without losing development units. To qualify for this density bonus, land in excess of the LOS standard for the proposed development shall be conveyed to the city, the park must be constructed, it must be four (4) acres or more, and its design must be accepted by the city.
Credit: Five percent (5%) increase in density for each one percent (1%) of the site dedicated to park land that is in excess of the city neighborhood park level of service standard (6 acres per 1,000 population), up to a maximum of twenty five percent (25%).
6. Provisions For Affordable Housing: "Moderate income housing" (or affordable housing) is defined as housing occupied or reserved for occupancy by households with a gross household income equal to or less than eighty percent (80%) of the median gross income for households of the same size in the county in which the city is located. Although providing for affordable housing is not a method for preserving open space, it is a public amenity listed in the bonus density program of the general plan, and may be included as a means to receive an increase in density as long as other open space amenities are incorporated into the development. Some of the techniques used to provide for affordable housing include the utilization of state or federal funds or tax incentives to promote the construction of moderate income housing, the utilization of programs offered by the Utah housing corporation, and the utilization of affordable housing programs administered by the Utah department of community and economic development. To qualify for this density bonus, a minimum of four (4) additional categories of the bonus density program must be implemented in the development and include the "public trails through and along the development" category, the design and quality of the moderate income housing shall be similar to the design and quality of all other housing in the development, and a minimum of five percent (5%) of the total housing must be dedicated to moderate income housing.
Credit: Twenty five percent (25%) increase in density for five percent (5%) of the total housing dedicated to moderate income housing.
Fifty percent (50%) increase in density for ten percent (10%) or more of the total housing dedicated to moderate income housing.
7. Landscaped Open Space: The objective of this density bonus is to encourage provisions for open areas that, pursuant to the general plan, preserve the open space character of the Washington Fields area and the area north of I-15. To qualify for this density bonus, the development shall provide for landscaped open space, with at least fifty percent (50%) of the landscaped areas visible from public streets. Landscaping shall be reflective of the area in which it is located and shall be developed as approved by the city. Xeriscape landscaping (drought tolerant vegetation) is encouraged for the type of vegetation, but the amount of vegetation must be dense enough to reflect the greenery of the area (especially if irrigation rights are still available for property in the Washington Fields area). Shade trees and shrubs shall be an integral part of the landscaping and shall meet sight distance requirements. All landscaping shall be installed by the developer and shall be maintained by the homeowners' association. The responsibility for landscape maintenance shall be cited on the plat, in the development agreement, and recorded against the properties within the development.
Credit: Three percent (3%) increase in density for each one percent (1%) of the site preserved in open space (not including areas within rights of way or areas that have received credit through other provisions of the bonus density program), up to a maximum of twenty five percent (25%).
8. Open Space At Intersection Corners At Periphery Of Development: Pursuant to the general plan, open areas created at intersection corners at the periphery of a development will generally make a greater contribution to preserving the open space character of the Washington Fields area and the area north of I-15 than open space internal to a development. To qualify for this density bonus, landscaping shall be reflective of the area in which it is located and shall be developed as approved by the city. Xeriscape landscaping (drought tolerant vegetation) is encouraged for the type of vegetation, but the amount of vegetation must be dense enough to reflect the greenery of the area (especially if irrigation rights are still available for property in the Washington Fields area). Shade trees and shrubs shall be an integral part of the landscaping and shall meet sight distance requirements. All landscaping shall be installed by the developer and shall be maintained by the homeowners' association. The responsibility for landscape maintenance shall be cited on the plat, in the development agreement, and recorded against the properties within the development.
Credit: Five percent (5%) increase in density for each one percent (1%) of the site preserved in open space that is located at intersection corners (not including areas within rights of way or areas that have received credit through other provisions of the bonus density program), up to a maximum of twenty five percent (25%).
9. Landscaped Rights Of Way And Front Yard Setbacks Along Arterials And Major Collectors: It is the city's desire, pursuant to the general plan, to preserve the open space character of the Washington Fields area and the area north of I-15 by having generous building setbacks with broad landscaped areas defined by open fencing. Therefore, along these major corridors, the following choices are available to qualify for a selection of density bonuses:
a. An additional landscape setback between the street ROW line and fence/wall of the development, beyond the required landscape strip for double frontage lots, shall be installed by the developer and shall be maintained by the homeowners' association. The responsibility for landscape maintenance shall be cited on the plat, in the development agreement, and recorded against the properties within the development. An average width of fifty feet (50') is desirable, with the width varying between thirty feet (30') and seventy feet (70'). A landscape setback of at least thirty feet (30') is required to get a density bonus.
b. Landscaping shall be reflective of the area in which it is located and shall be developed as approved by the city. Xeriscape landscaping (drought tolerant vegetation) is encouraged for the type of vegetation, but the amount of vegetation must be dense enough to reflect the greenery of the area (especially if irrigation rights are still available for property in the Washington Fields area). Shade trees and shrubs shall be an integral part of the landscaping and shall meet sight distance requirements.
c. The desired fencing along the major roadway corridors is open three (3) rail or four (4) rail fencing. Wrought iron fencing and/or solid fence/wall panels may be as approved by the city if they match or are compatible with fences of adjoining developments. Overall transparency of at least fifty percent (50%) is required to get a density bonus. (Note: Thin wire mesh fencing, as approved by the city, may be used to confine animals and/or children.)
Credit: If a landscape setback varying between thirty feet (30') and seventy feet (70'), with an average of at least fifty feet (50') is created, with no section less than thirty feet (30') wide, the bonus density will be five percent (5%) for each one percent (1%) of the total land area of the parcel that is in the landscape setback, up to a maximum of twenty five percent (25%).
Where homes face arterials and major collectors, a five percent (5%) density credit will be granted for each ten feet (10') of building setback beyond the minimum front yard setback of the closest size range, up to a maximum of twenty five percent (25%).
If fencing is less than seventy five percent (75%) transparent but at least fifty percent (50%) transparent, a density increase may be transferred to the rest of the property. The density credit will be derived by dividing the area of the landscape setback by the average lot size of the development. (Hypothetical example: 30 foot landscape setback x 1,000 foot property length = 30,000 square feet/15,000 square foot average lot size = total of 2 additional lots.)
If fencing is seventy five percent (75%) or more transparent, a density increase may be transferred to the rest of the property. The density credit will be derived by dividing the area of the landscape setback by the average lot size of the development, plus fifty percent (50%). (Hypothetical example: 30 foot landscape setback x 1,000 foot property length = 30,000 square feet/15,000 square foot average lot size = 2 units + 50 percent = total of 3 additional lots.)
10. Public Trails Through And Along Development: Where indicated in the general plan and/or city trails plan, the proposed development shall provide public trails that generally follow trail alignments shown in said plans. Unless otherwise approved by the city, trail alignments must traverse through the property or around its periphery, according to the plans. To qualify for this density bonus, trails shall be open to the general public, and shall connect to adjacent trails, parks, open space and public streets, in a manner as approved by the city. The trails shall be a minimum of ten feet (10') wide, meet AASHTO standards, and shall be installed by the developer. Trail maintenance responsibility will be as agreed upon in the development agreement. If trails are proposed that are not indicated in the general plan and/or city trails plan, a density bonus may be granted for these trails as well. To qualify for a density bonus for these trails, the same criteria as outlined for trails indicated in the general plan and/or city trails plan shall be met. Again, trail maintenance responsibility will be as agreed upon in the development agreement.
Credit: Twenty five percent (25%) increase in density.
11. Tree Lined Streets: Tree lined street sections for all streets (internal and periphery) are desirable to provide shade for sidewalks (encourage walking) and to reduce solar heat gain on streets and buildings. To qualify for this density bonus, all streets within the development, on both sides of the streets, shall have a landscape strip between the curb and sidewalk, planted with shade trees at forty foot (40') spacing or less. The shade trees shall be from twenty four inch (24") box containers with a minimum caliper of one and one-half inch (11/2") (1 inch above grade). Smaller trees may be interplanted where overhead obstructions (power lines, etc.) may result in problems that could be caused by the taller varieties. However, the sizes of the trees at planting are to remain the same. A list of approved tree species and landscaping guidelines are available in the community development department. As approved by the city, trees may be grouped and/or staggered as long as the average spacing of forty feet (40') is maintained.
Credit: Twenty five percent (25%) increase in density.
12. Miscellaneous Public Benefits: Other types of open space benefits, such as school sites, recreation centers, libraries, fire stations, the pooling of adjoining properties for regional detention basins, regional parks or other public benefits, etc., may also be explored for inclusion into bonus density credits. These facilities will have to incorporate a degree of open space in their design, and the design will have to be approved by the city, with the density bonus credit determined during the project's evaluation. (Ord. 2005-40, 11-14-2005)