Auburn controls site coverage through a maximum Impervious Surface Ratio (ISR) rather than a simple building-footprint percentage. Conventional single-family lots are generally capped at an ISR of 0.35, while Neighborhood Conservation districts range from 0.15 to 0.50. Accessory structures cannot push a lot over its ISR limit, and total accessory floor area is capped at 50% of the principal structure.
Instead of a single building-coverage percentage, Auburn regulates how much of a lot can be covered by impervious surfaces. "Impervious Surface Ratio (ISR)" is defined (Section 202/Section 203 area) as the total area of all impervious surfaces (buildings, driveways, walks, patios, pavement) divided by the total site area; the water surface of swimming pools is excluded. For conventional single-family subdivisions, Table 5-1 sets the maximum ISR at 0.35 for lots under 30,000 sq ft, with sliding formulas reducing the effective ratio on larger lots (e.g., 0.24 for the first 39,999 sq ft on the largest category). In Neighborhood Conservation districts, Table 5-2 sets ISR from 0.15 (the largest-lot NC-150/NC-100 districts) up to 0.50 (NC-4 and NC-5), generally rising as minimum lot size falls. Urban, mixed-use and redevelopment districts allow higher ISR (for example, 0.75 for certain mixed-use, multiple-unit and private-dormitory uses), and Table 4-3 governs non-residential ISR and Floor Area Ratio (FAR). Accessory structures may not cause a lot to exceed its maximum permitted ISR (Section 511.03.C), and on any residential lot the total accessory floor area of all structures is limited to 50% of the principal structure's floor area (Section 511.03.J), excluding swimming pools. Site plans submitted for permits must show total proposed impervious surface area so the city can confirm compliance.
Adding driveways, patios, pools decks or accessory buildings that push a lot's impervious surface over its maximum ISR, or exceeding the 50% accessory-floor-area cap, violates the Zoning Ordinance and can result in permit denial, citations, and a requirement to remove impervious area or obtain a variance.
Other ordinances people look up for this city. Green dot = verified primary-source excerpt.
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Auburn requires premises to be kept free from weeds or plant growth over 12 inches, and noxious weeds are prohibited. Weeds are defined as grasses, annual pl...
See how Auburn's lot coverage limits rules stack up against other locations.
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