For the standard Chicago lot size of 25’ x 125’, giving a lot area of 3,125 square feet, new homes must conform to these requirements (see zoning criteria):
- Max. of one dwelling unit
- Max. of 2,812.5 square feet of interior floor area (basement space more than halfway below ground excluded)
- Max. height of 30 feet (mean calculation with gabled roofs)
- Min. front setback is average of the two properties on each side of the subject lot
- Min. side setback total of both sides is 5 feet where no side is less than 2 feet
- Min. rear setback is 30 feet
- Min. rear yard open space is 225 square feet
- Min. of two parking spaces
Additions to existing homes must also conform to these requirements except the parking requirement doesn’t kick in unless there is a change in the number of dwelling units.
The zoning code does allow for “zoning relief” that can be applied for to reduce the extent of these criteria (see http://chicago47.org/zoning for an explanation of each).