Infill Housing Standards for Single-Family Dwellings
Changes current as of January 1, 2008
>Click here for the presentation given to the City Commission on the new standards. This also includes illustrations of the new standards.
>Decatur City Code
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Definitions
Basement
That portion of a building having a part but not more than one-half of its height below grade. A basement is not counted as a story for the purpose of height regulation.
Building height
The vertical distance from the mean finished ground level at the front of the building to the highest point of a roof.
Lot Coverage
A percentage factor which, when multiplied by the total area of any lot, establishes the total area of impervious cover which may be built on said lot. Where used in the zoning ordinance, the term coverage shall mean lot coverage.
Residential floor area
The gross horizontal areas of the several floors of a dwelling, including
attics with headroom or vertical height between floor and ceiling of seven (7) feet or greater and served by a permanent stair, attached garages and other enclosed areas, detached garages and other accessory buildings, but exclusive of basements and cellars, open porches, balconies or decks. Floor area shall be measured from the exterior faces of the exterior walls.
Floor area ratio (FAR)
A number which, when multiplied by the total area of any lot, establishes the total amount of floor area which may be built on that lot.
Impervious Cover
A surface composed of any material that significantly impedes or prevents the natural infiltration of water into soil. Impervious surfaces include, but are not limited to, rooftops, buildings, drives, parking spaces, walkways, decks, tennis courts, swimming pools and similar structures, compacted gravel, and any concrete or asphalt surface.
Accessory buildings
In R-85, R-60, and HDSF zoning districts shall not exceed 1,000 square feet of total floor area, including garages and other enclosed storage areas. Such buildings shall not exceed 25 feet in height and 2 stories.
Development Standards
R-85 Single-Family Residential District
Maximum lot coverage is 40%.
Maximum building height is 35 feet and 2½ stories.
The maximum floor area ratio is 0.40.
R-60 Single-Family Residential District
Maximum lot coverage remains at 40% for standard lots.
Maximum building height is 35 feet and 2½ stories.
The maximum floor area ratio is 0.40.
The minimum side yard for corner lots is 10 feet.
Parking Requirements
Off-street parking required for single-family dwelling is one space. The required parking space must be located to the rear of the front building line.
Circular driveways are prohibited.
Height Modifications
Instead of measuring the “front door elevation” we will measure the “first floor elevation”.
Where an existing dwelling is to be demolished and replaced with a new dwelling, the finished floor elevation of the first floor of the proposed dwelling may be no more than two (2) feet above the finished floor elevation of the first floor of the dwelling to be demolished. The elevation of the ground level at the front of the proposed dwelling may be raised no more than two (2) feet above the elevation of the existing ground level at the front of the building prior to construction.
Where a new dwelling is to be built on a previously undeveloped lot that is within 100 feet of existing dwellings on both sides, the finished floor elevation of the first floor of the new dwelling shall be no higher than one of the following standards below:
(1) three (3) feet above the existing elevation of the ground at the front building setback line; or
(2) the average finished floor elevation of the first floors of the existing dwellings on either side of the undeveloped lot.
Where a new dwelling is to be built on a previously undeveloped lot that is not within 100 feet of existing dwellings on both sides, the finished floor elevation of the first floor of the new dwelling may be no more than three (3) feet above the existing elevation of the ground at the front building setback line.
Reduction of Maximum Building Height
Reduction of maximum building height. Where a lot of record in an R-60 zoning district at the time of the effective date of this ordinance had less than the required minimum lot width, the maximum building height shall be reduced by one-half (½) foot for each foot that the lot width is less than sixty (60) feet.
General Yard Modifications
Reduction of minimum side yard. Where a lot of record in an R-60 zoning district at the time of the effective date of this ordinance had less than the required minimum lot width, one of the minimum required side yards may be reduced by one (1) foot for each two (2) feet that the lot width is less than sixty (60) feet, under the following conditions:
a. There is a minimum distance of ten (10) feet between the dwelling and the principal building on the property adjacent to the reduced side yard.
b. No side yard may be reduced below a minimum of five (5) feet.
Lot coverage. Where a lot of record in an R-60 zoning district at the time of the effective date of this ordinance had less than the required minimum lot area, the maximum lot coverage permitted may be increased by the use of the following formula:
(0.4) (lot area in sf) + (lot area in sf / 9,000 sf) (3,600 sf - (0.4) (lot area in sf))
In the above formula, ‘sf ’ is an abbreviation of the term ‘square feet.’ For example, maximum lot coverage for a 7,500 sf lot would be calculated as follows:
(0.4) (7,500 sf) + (7,500 sf /9,000 sf ) (3,600 sf - (0.4) (7,500 sf)) =
3,000 sf + (0.833) (600 sf) = 3,500 sf
3,500 sf = 46.6%
7,500 sf ”
Existing lot coverage. The lot coverage of properties developed with existing single-family dwellings where the existing lot coverage exceeds the maximum lot coverage permitted may be modified as long as the proposed lot coverage does not exceed the existing lot coverage.