Lot Coverage

Lot coverage is the ratio of an occupied area (buildings and driveways) compared to the total area of the lot. Lot coverage restrictions exist in several districts, see Zoning Ordinance §3.2.5.B for details. Coverage provisions are applicable to both new construction and additions, as well as any homes that do not conform to these guidelines.

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Lot Coverage Calculations

The Zoning Ordinance includes, but is not limited to the following items in lot coverage calculations:

  • Main buildings (resting directly or indirectly on the ground), detached garages and accessory buildings
  • Paved driveways and parking pads
  • Pergolas
  • In-ground swimming pools
  • Bay windows

Examples of items not included:

  • Air conditioners and compressors, with or without foundations
  • Sidewalks and walkways
  • Areaways going from ground level to basements
  • Play equipment, picnic tables, benches and other outdoor furniture

Homes with front porches and detached garages in the backyard gain an incentive “bonus” when calculating lot coverage; properties with one or both of those features are eligible to increase their maximum lot coverage by a certain amount of percentage points. 

Learn more about specific allowances by zoning district

Frequently Asked Questions

The coverage requirement allows a bonus for porches on the front of the house. How do you determine what the front of a house is?

The front of the house is referred to as “lot line, front” in Zoning Ordinance §18.2, and is defined as the lot line fronting a street or the legally required access to the lot. On a corner lot, it is the shortest of those lot lines which front a street. Where a corner lot has equal frontage on two or more streets, the front lot line will be the lot line on that street on which the greatest number of lots front within the block.

The coverage provision includes a 3 percent coverage bonus for a main building footprint with a porch attached to the front of a house. Any porch or portion of porch that is not attached to the front of the house would not be eligible for this bonus. The front porch must also have a minimum area of 60 sq. ft. to be eligible for the bonus.

Can a one-family structure have a second-story addition if it currently does not comply with coverage requirements?

A homeowner can add a second story (straight up without any protrusion beyond the existing footprint) to an existing dwelling that is nonconforming to coverage. In general, a homeowner can add to a nonconforming structure as long as the addition complies with Zoning Ordinance requirements for setback and height.

Why does the Zoning Ordinance address total coverage for undersized lots?

There was never any intention to provide relief on total coverage for undersized lots. The issue that was discussed (as directed by the County Board and the public) was the unfair restriction on house sizes that may result from the proposed amendments on undersized lots. To address this issue, the following provision was added Zoning Ordinance § 3.2.5.A.2.

Maximum main building footprint coverage on undersized lots in a specific zoning district shall be the same square footage as permitted on a standard sized lot (ex: 6,000 sq. ft. in R-6) in that zoning district (subject to all applicable setback requirements).