A. Blocks:
1. Blocks should be limited in size and be laid out in a pattern that ensures the connectivity of streets, provides for efficient provision of public and safety services, and establishes efficient and logical routes between residences and nonresidential destinations and public gathering places.
2. Block Lengths:
a. Except as required by Article 14-2H (Form-Based Zones And Standards), to provide multiple travel routes within and between neighborhoods, block faces along local and collector streets should range between three hundred (300) and six hundred feet (600') in length and for residential subdivisions have a width sufficient to accommodate two (2) tiers of lots. Longer block faces may be allowed in cases of large lot commercial, industrial, or rural residential development, or where topography, water features, or existing development prevents shorter block lengths, although midblock pedestrian connections may be required (see section 15-3-3 of this chapter). Block faces are measured from centerline to centerline.
b. Where the area is subject to Article 14-2H (Form-Based Zones And Standards), the block network shall substantially comply with the Form-Based Code Future Land Use Map in the Comprehensive Plan and shall meet the following standards:
(1) Individual block lengths and the total block perimeter shall comply with the standards in Table 15-3-4A-1 (Block Size Standards). Where a block contains multiple Form-Based Zones, the most intense zone is to be used to establish the standards for block size. Blocks may exceed the maximum allowed length if a compliant passage (14-2H-9L) is provided to break up the block.
Zone | Length (max.) | Length (max.) With Passage1 |
Perimeter Length | Perimeter Length With Passage1 |
Zone | Length (max.) | Length (max.) With Passage1 |
Perimeter Length | Perimeter Length With Passage1 |
T3 NE | 500' max. | 800' max. | 1,600' max. | 2,200' max. |
T3 NG | 500' max. | 800' max. | 1,600' max. | 2,200' max. |
T4 NS | 360' max. | 600' max. | 1,440' max. | 1,950' max. |
T4 NM | 360' max. | 600' max. | 1,440' max. | 1,950' max. |
T4 MS | 360' max. | 500' max. | 1,440' max. | 1,750' max. |
1 In compliance with the standards for a passage in sub-section 14-2H-9L (Passage). | ||||
Key: _ . . _ Block Perimeter _ . . _ Design Site
(2) Blocks shall be a minimum width to result in two (2) halves of developable design sites in compliance with the minimum design site depth standards of the allowed building types in the Form-Based Zone. When the zone has a range of minimum design site depths, the applicant may show the shortest minimum design site depth with an acknowledgement that the selected depth may not accommodate the full range of building types allowed by the zone. A single half is allowed when adjoining an existing half-block.
(3) The size, shape, length, location, and design of blocks may vary from the Future Land Use Map where required to accommodate sensitive areas, or where the variation complies maintains street connectivity, complies with Table 15-3-4A-1 (Block Size Standards, minimizes changes to Form-Based Zones on each block, and adjusts all blocks affected by the proposed change(s). Where this affects the location, shape, or design of civic space, the variation shall maintain civic space of a similar size in a nearby location within the subdivision.
3. Block faces along arterial streets should be at least six hundred feet (600') in length. Intersecting collector streets should be spaced in a manner that provides adequate connectivity between neighborhoods, but also maintains the capacity of the street for the safe and efficient movement of traffic. Longer block faces may be required along high capacity or higher speed arterial streets where the interests in moving traffic outweigh the connectivity between areas of development. The city may approve shorter block faces in high density commercial areas or other areas with high pedestrian counts.
4. Cul-de-sacs may not exceed nine hundred feet (900') in length. The length of a cul-de-sac is measured from the centerline of the street from which it commences to the center of the bulb.
B. Lots:
1. Lots must be platted in a manner that will allow development that meets all requirements of title 14, "Zoning Code", of this code. Lots and design sites must be of sufficient size to accommodate an adequate buildable area and area for required setbacks, off street parking, and service facilities required by the type of use and development anticipated.
2. Lots with multiple frontages must be platted large enough to accommodate front setback requirements along street side lot lines.
3. If a property with frontage along an arterial street is proposed to be subdivided, developed or redeveloped for any multi-family, group living, commercial, institutional or industrial use, a cross access easement must be provided by the property owner to all adjoining properties that front on the same arterial street that are or may be developed as multi-family, group living, commercial, institutional use, or industrial uses according to the cross access standards set forth in section 14-5C-7 of this code.
4. In residential areas, double and triple frontage lots shall be avoided. Where such lots are necessary to overcome specific disadvantages of topography, land features, or access restrictions, the following standards apply:
a. Lots with multiple frontages shall be one hundred twenty five percent (125%) of the required lot area for the zone in which the lot is located. The additional required lot area shall be used to increase the depth of the lot between street frontages. Corner lots with only two (2) frontages are exempt from this requirement, however, said corner lots should be platted with enough land area to accommodate the required front setback area along both frontages.
b. Double and triple frontage lots where dwellings will have side or rear building facades oriented toward an arterial street shall provide a minimum twenty foot (20') wide landscaped buffer area along the arterial street frontage. The buffer area shall be planted with a mixture of coniferous and deciduous vegetation approved by the city forester. The vegetation shall be required along with other public improvements for the property. Lots where dwellings will have front building facades oriented toward an arterial street are exempt from this requirement. If a buffer area was required during subdivision, no solid fences will be allowed within this buffer area. This restriction must be noted in the subdivider's agreement and on the plat. On corner lots, the landscaping within the buffer must be planted and maintained to comply with intersection visibility standards.
5. Side lot lines shall approximate right angles to straight street lines or be approximately radial to curved street lines, except where a variation will provide a better street and lot layout. For purposes of this subsection, "approximate right angles" means angles between eighty degrees (80°) and one hundred degrees (100°).
6. Residential lots shall not be designed with irregular shapes such as a flag or panhandle shape where the structure on the lot may be hidden from the street behind another structure.
7. In residential subdivisions, lots must be arranged to allow easy access to public open space. The subdivision layout should be designed so that the location and access to public open space is readily apparent to the public. Subdivision layouts where public open space is surrounded by private lots that back up to the public open space are discouraged. Techniques, such as single loaded streets along park edges or along segments of park edges and well marked trail easements are to be utilized to satisfy this requirement.
C. Provisions To Minimize The Effect Of Highway Noise: Subdivisions adjacent to or within three hundred feet (300') of the Interstate 80 and/or the Highway 218 rights of way shall comply with the following provisions, intended to reduce the effect of highway noise on residential areas:
1. Any portion of a residential lot that is within three hundred feet (300') of the Interstate 80 or Highway 218 right of way shall be identified as a noise buffer, and no residential structure will be permitted within this three hundred foot (300') buffer area. The buffer area shall be planted with a mixture of coniferous and deciduous vegetation approved by the city forester. The vegetation shall be required along with other public improvements for the property. Existing trees and vegetation may be used to comply with this requirement as approved by the city forester. Accessory structures and yards are permitted within the three hundred foot (300') buffer area provided the required vegetative buffer is maintained.
2. The three hundred foot (300') buffer for residential structures may be reduced with approval by the city if the subdivider constructs an earthen berm, decorative wall, or other similar structure and demonstrates that the highway noise just outside the proposed residential structures will be no more than sixty (60) dB.
3. The three hundred foot (300') buffer for residential structures may also be reduced with approval by the city if the subdivider demonstrates that existing topography results in highway noise being no more than sixty (60) dB just outside the proposed residential structures. (Ord. 08-4313, 8-26-2008; amd. Ord. 21-4866, 11-16-2021)