(A) Accessory buildings. No accessory building shall be constructed upon a lot until the construction of the principal building has been actually commenced, and no accessory building shall be used unless the principal building is also being used.
(1) Detached accessory buildings.
(a) No detached accessory building shall be erected within the minimum setback required along any street, or within the minimum side yard setback required for a principal structure. Accessory buildings shall be located a minimum of ten feet from any other building or structure other than a fence on the same property unless fire protection is installed within the accessory building in accordance with the provisions of the Urbandale Building Code for an attached garage, in which case such minimum separation may be reduced to six feet. An accessory building shall not exceed 12 feet in height, except as provided herein.
(b) Detached accessory buildings for a single-family residence shall not occupy more than 30% of the dwelling’s rear yard; shall have minimum setbacks of three feet from all property lines if the building’s main floor is 720 square feet or less in area; minimum setback of ten feet from the rear property line and comply with the minimum side yard setbacks for the principal structure if the building’s main floor area is more than 720 square feet but less than 1,000 square feet, or if a detached accessory building exceeds 12 feet but is not more than 14 feet in height; and shall comply with all setback requirements for a principal structure if the building’s main floor area exceeds 1,000 square feet of floor area or if a detached accessory building has a height of more than 14 feet.
(c) Detached accessory buildings for multi-family or nonresidential uses shall have minimum setbacks of ten feet from all property lines if the building’s main floor has less than 1,000 square feet of area; and shall have minimum setbacks of 25 feet from all property lines if the building’s main floor area exceeds 1,000 square feet or if the building has a height of more than 12 feet.
(d) No detached accessory building shall exceed a height of 25 feet in any case.
(2) Attached accessory buildings. Accessory buildings except structures used to house urban or other livestock may be attached to the principal building provided that the accessory building complies with all yard requirements for a principal building, regardless of whether the connection consists of a common wall or a connection by a breezeway or open porch. If the connection is by breezeway or porch, a separation shall be maintained between the principal and accessory structures in accordance with division (A)(1) above.
(3) Additions creating nonconformity.
(a) In the event that a legally existing detached accessory building will be made nonconforming by reason of being placed in a side yard by an addition to a principal building, such existing accessory building may be retained as a legal nonconforming structure provided the following conditions have been met.
1. The existing accessory building and the addition to the principal building comply with all other zoning regulations and the Urbandale Building and Fire Codes including but not limited to separation between principal and accessory structures and other regulations specified by divisions (A)(1) and (A)(2) above.
2. The location and design of the addition to the principal building is determined by the Zoning Administrator to be the only reasonable and practical location for the addition.
3. The accessory building has been in existence for a minimum of three years as determined by the date of the certificate of occupancy or other verifiable means.
4. The Zoning Administrator determines that the nonconformity created does not alter the character of the neighborhood nor impair health, safety or general welfare.
(b) Such nonconforming accessory building shall not be constructed as part of the principal building nor attached thereto by a breezeway or similar structure.
(c) Such nonconforming accessory building shall be subject to the provisions of § 160.59 and shall not be extended, enlarged, reconstructed, moved, or structurally altered except when required to do so by law or order or so as to be in full compliance with divisions (A)(1), (A)(2) and (A)(3) above and other applicable regulations and requirements of this and other applicable codes, and if damaged to the extent of more than 50% of its assessed value, or is abandoned or becomes obsolete, it shall not be restored except as to comply with the provisions of divisions (A)(1), (A)(2) and (A)(3) above and all other applicable regulations and requirements.
(d) If a building permit is denied by the Zoning Administrator because of failure to meet divisions (A)(3)(a)1. through (A)(3)(a)4. above or for other reasons specified by this Code, the applicant may appeal the decision to the Board of Adjustment.
(4) Providing area for accessory structures. Area should be provided for accessory buildings on properties zoned for detached single-family residences by preserving an area upon which a 22 feet by 22 feet detached structure or a 12 by 22 feet attached accessory structure can be located in compliance with all applicable regulations. Such area and access thereto shall have a slope of 5% or less and be suited for the intended purpose. Failure to include such provisions shall be grounds for rejecting plans for a principal structure or additions thereto.
(B) Fences and walls.
(1) Residential, fences may be placed on the property line unless limited by easements and except as restricted herein. Fences or walls shall not exceed a height of six feet if located in the minimum rear or sideyard setback; shall not exceed a height of four feet in any front yard; and shall not exceed a height of eight feet in any case. Fences and walls shall be setback a minimum of two feet from any public right-of-way. Fences shall not be placed in the minimum setback along any street of any lot created after July 1, 2000.
(2) Security fences are permitted in nonresidential districts other than the “A-1,” “A-2,” “FW” and “FF” Districts but shall not exceed ten feet in height and shall be of woven wire, wrought iron or similar type of non-opaque fencing. Razor wire and other sharp or dangerous fencing shall not be allowed.
(3) Farm Fences of any height shall be permitted in connection with any farm use, except that the vision clearance triangles shall be maintained at all intersections.
(C) Lot required for each principal structure. All principal structures shall be located on a zoning lot; and only one principal structure shall be located, erected or moved onto a zoning lot.
(D) Corner lots.
(1) Corner lots created after July 1, 2000 shall be a minimum of twenty feet wider than the minimum lot width required by the zoning district the lot is located in, and corner lots with side yards adjoining a municipal arterial or other street carrying higher traffic volumes shall be a minimum of 40 feet wider than the minimum lot width required by the district.
(2) For corner lots made of record after September 26, 1974, the minimum setback along the longer street frontage shall be equal to or greater than the minimum front yard setback required for that district or classification, depending on divisions (F) below and other requirements of this section.
(3) For corner lots made of record on or before September 26, 1974, the minimum side yard setback shall apply to the longer street frontage of the lot except in the case of reverse frontage lot, defined as a corner lot whose side yard adjoins the street that the lot to the rear fronts on. The minimum setback on the longer street frontage on reverse frontage lots shall be one-half of the minimum front setback required for the lot to the rear of the reverse frontage lot, and accessory buildings on the reverse frontage lot shall not project beyond the minimum front setback of the lot to the rear. However, the setback on the longer street frontage of reverse frontage lots of record on or before September 26, 1974 shall be reduced to the minimum extent necessary to provide a minimum buildable width of 28 feet on said lot, and if necessary so erection of an accessory building is possible.
(E) Vision clearance triangle. A vision clearance triangle shall be provided and maintained in every quadrant of every street intersection, said triangle being bounded by the street right-of-way lines and a line connecting points on said rights-of-way lines that are located not less than 25 feet from their point of intersection. No vegetation or structure shall be allowed to exist within said vision clearance triangle that is more than two and one-half feet and less ten feet above the elevations of said street right-of-way lines, except traffic control signs, street lights and public utility poles or appurtenances that by need and function cannot reasonably be located outside of said vision clearance triangle.
(F) Increased setbacks required.
(1) Arterial and collector streets. For lots created after July 1, 2000 in the “A-1,” “A-2,” “R-1L,” “R-1I,” “R-1S,” “R-2,” “R-3” and “R-4” Districts, the minimum setback along a collector street shall be the minimum required by the zoning district or 35 feet, whichever is more. The minimum setback in said districts along an arterial street shall be the minimum required by the zoning district or 50 feet, whichever is more. The increased setback requirement shall apply regardless of whether the adjoining yard is a front, side or rear yard.
(2) Platted setback. If a plat of record is drawn with a setback that is greater than the minimum setback otherwise required by this Code, the platted setback shall be enforced as the minimum requirement.
(3) Average front yard. In the “A-1,” “A-2,” “R-1L,” “R-1I,” “R-1S,” “R-2,” “R-3” and “R-4” Districts, the required front setback shall be increased to the average of the existing front yards of the abutting principal buildings on each side of any lot, to a maximum setback of 50 feet on a local or collector street and maximum of 75 feet on an arterial street. Additions in the front yards of existing buildings shall not project beyond the average existing setbacks of the principal buildings on the abutting lots.
(4) Planned full right-of-way width not existing. If the entire minimum right-of-way width as set out in the Subdivision Code has not been acquired for a public street according to its classification, the minimum setbacks along the side of the street where additional right-of-way is to be acquired shall be increased in the amount specified herein, and the minimum setbacks shall be measured from the centerline of said street. The amount of increase shall be in accordance with the classification of the street by the City Engineer, Comprehensive Plan and Subdivision Code, as follows: local street, 25 feet; collector street, 30 feet; arterial street, 60 feet.
(5) Lot adjoining a more restrictive district. If a lot line is the boundary of a more restrictive zoning district, the minimum width of the side yard or rear yard on that side directly abutting the more restrictive district shall equal or exceed the minimum setback of the adjoining yard of the lot in the more restrictive district. If the minimum setback along the street in the less restrictive district is smaller than that of a more restrictive district, said setback shall be increased to equal or exceed the average of the minimum setbacks required along the street in the two districts, for a minimum of 150 feet from the district boundary line.
(G) Minimum lot depth. The minimum lot depth shall be 115 feet as measured at the shallowest point unless the lot backs up to an arterial street, in which case the minimum lot depth shall be 175 feet.
(H) Street frontage required. All lots shall have frontage on a street and obtain vehicular access from a street. Lots that front onto a public street shall have a minimum of 45 feet of frontage, or 75% of the minimum lot width required by the zoning district in which the lot is located if the minimum lot width requirement is less than 70 feet, except for lots that front on cul-de-sac turnarounds. The minimum frontage of lots on cul-de-sac turnarounds shall be not less than 65% of the minimum lot width required by the zoning district. In all cases, minimum frontages shall be as measured within a single segment of right-of-way, in the case of intermittent or multiple frontages.
(I) Impervious surface in front yard. Not more than 35% of the front yard of any single- family dwelling unit shall be paved, provided that this shall not be construed to prohibit a two-car driveway together with a paved apron leading to parking spaces located behind the minimum setback line.
(J) Landscaping and vegetation exempted. Landscaping and other vegetation is exempt from the setback requirements of this Code, except as follows: no hedge, landscape planting or other vegetation shall be allowed to materially impede vision across a front or street side yard between the heights of four feet and ten feet; or obstruct a sidewalk by reason of having branches or foliage that is less than two feet from or less than ten feet above any public right-of-way.
(K) Dish antennas, wind towers and solar arrays.
(1) Dish antennas that exceed 40 inches in diameter shall not be placed in a front yard or a street side yard unless it can be shown that such size is essential to the reception of transmissions, and that no other viable location exists.
(2) Antennas, wind towers and solar arrays shall conform to the minimum setbacks and maximum height regulations for accessory structures.
(L) Private sewage and water systems. If public sewage service is not reasonably available, as determined by the City Engineer, the minimum lot width and area shall be 150 feet and one acre respectively, or larger if greater width or area is found to be necessary by the County Health Department or City Engineer to maintain safe and healthy conditions for a private well for domestic water supply or an on-site sewage disposal system.
(M) Hazardous site conditions. No land shall be used or structure erected if the Zoning Administrator determines that the lot or site is unsuitable for such use or structure by reason of flooding, concentrated runoff, inadequate drainage, adverse soil or rock formation, unfavorable topography, low percolation rate, low bearing strength, to erosion, or any other condition that appears likely to be detrimental to health, safety or general welfare. The Zoning Administrator, in applying the provisions of this section, shall in writing recite the particular facts upon which he bases his conclusion that the land is not suitable for certain uses.