§ 155-18.10  MEASUREMENTS AND EXCEPTIONS (LOT AND BUILDING REGULATIONS).
   (A)   Lot area.  Lot area includes the total land area contained within the property lines of a lot.
   (B)   Lot area per unit.  Lot area per unit refers to the amount of lot area required for each dwelling unit on the subject parcel. For example, if a minimum parcel-area-per-unit standard of 1,000 square feet is applied to an 8,750 square foot parcel, a maximum of eight dwelling units would be allowed on that parcel.
   (C)   Lot frontage.  Lot frontage is measured along the right-of-way line between opposite-side boundaries of the lot. Lot frontage on cul-de-sac bulbs is measured at the actual building line. The street frontage of a lot or parcel that is legally created or described as extending to the center line of a street must be measured along the line that denotes the edge or boundary of the easement established for the street.
   (D)   Building coverage.  Building coverage is the area of a lot covered by principal and accessory buildings, as measured along the building line. Only building areas beneath a roof are counted for purposes of measuring building coverage. A porch with a roof, for example, is counted, but an uncovered deck structure is not considered building coverage.
   (E)   Setbacks.
      (1)   Street setbacks.
         (a)   Measurement.  Street setbacks are measured from the right-of-way line or the centerline of the abutting street (as indicated by the subject district provisions) to the closest point of the building or structure.
         (b)   Permitted obstructions/ encroachments.  Street setbacks must be unobstructed and unoccupied from the ground to the sky except as expressly allowed in division (F) of this section.
         (c)   Double frontage lots.  On double-frontage lots, the Zoning Administrator is authorized to establish which of the frontages constitutes the front lot line (and is thereby subject to street setback regulations) based on factors such as the pattern of front and rear yards on the subject blockface, existing limitations on street access, where the building's "front" door is located or other reasonable considerations. Only such obstructions permitted in street setback may be located in that part of a rear setback adjoining a street that is equivalent in depth to a required front setback, except for lots backing to thoroughfares in subdivisions where no-access strips have been provided on the recorded plat.
         (d)   Exceptions for established setbacks.  When existing buildings on one or more abutting lots are closer to the street property line than the otherwise required street setback, additions to existing residential buildings or construction of new residential buildings on the subject lot may comply with the average street yard depth that exists on the nearest two lots on either side of the subject lot instead of complying with the zoning district's minimum street setback requirement.
            1.   If one or more of the lots required to be included in the averaging calculation is vacant, the vacant lot will be deemed to have a street yard depth equal to the minimum street setback requirement of the subject zoning district.
 
            2.   Lots with frontage on a different street than the subject lot or that are separated from the subject lot by a street or alley may not be used in computing the average.
 
            3.   When the subject lot is a corner lot, the average street yard depth will be computed on the basis of the nearest two lots with frontage on the same street as the subject lot.
 
            4.    When the subject lot abuts a corner lot with frontage on the same street, the average street yard depth will be computed on the basis of the abutting corner lot and the nearest two lots with frontage on the same street as the subject lot.
      (2)   Rear setbacks.
         (a)   Measurement.  Rear setbacks are measured from the rear property line to the closest point of the building.
         (b)   Permitted obstructions/ encroachments.  Rear setbacks must be unobstructed and unoccupied from the ground to the sky except as expressly allowed in division (F) of this section.
         (c)   Corner lots.  No rear setback is required on corner lots.
      (3)   Side setbacks.
         (a)   Measurement.  Side setbacks are measured from the interior (non-street) side property line to the closest point of the building.
         (b)   Permitted obstructions/ encroachments.  Side setbacks must be unobstructed and unoccupied from the ground to the sky except as expressly allowed in division (F) of this section.
   (F)   Features allowed to encroach in required setbacks.  Required setbacks must be unobstructed and unoccupied from the ground to the sky except that features are allowed to encroach into required setbacks to the extent indicated in the following table. These structures and building features are not subject to minimum lot area or lot frontage regulations.
 
Obstruction/Projection into Required Setback
Street
Side
Rear
Arbors, trellises and pergolas
Yes
Yes
Yes
Awnings, canopies and light shelves and architecturally integrated solar shading devices projecting no more than 10 feet and with at least 7 feet of clear height above the ground below
Yes
Yes
Yes
Balconies
No
No
Yes
Bay windows that project no more than 3 feet and are no more one story in height
Yes
No
Yes
Breezeways
No
No
Yes
Chimneys and flues that project no more than 18 inches into the required setback
Yes
Yes
Yes
Decks, porches, patios, terraces (open) and similar features up to 4 feet in height above average grade and without roofs
Yes
Yes
Yes
Geothermal pumps and associated equipment up to 4 feet in height
Yes
Yes
Yes
Satellite dish antennas, not exceeding 1 meter (39.37 inches) in diameter
Yes
Yes
Yes
Satellite dish antennas, over 1 meter but not exceeding 2.4 meters (94.49 inches) in diameter
No
No
Yes
Eaves, gutters and roof overhangs projecting no more than 3 feet
Yes
No
Yes
Eaves, gutters and roof overhangs projecting no more than 2 feet or 40% of required setback depth, whichever is less
Yes
Yes
Yes
Fences, walls and hedges, subject to § 155-14.90
Yes
Yes
Yes
Flagpoles, mailboxes and other typical street yard features
Yes
Yes
Yes
Fountains, sculptures, landscape planters and similar landscape and ornamental objects
Yes
Yes
Yes
Insulation added to the outside of the exterior wall of an existing building
Yes
Yes
Yes
Parking, enclosed (attached or detached)
No
No
Yes
Rain gardens
Yes
Yes
Yes
Rain barrels up to 5 feet in height
Yes
Yes
Yes
Sills, belt courses, cornices, buttresses and other architectural features
Yes
Yes
Yes
Solar energy systems, building-mounted
Yes
Yes
Yes
Solar energy systems, ground-mounted
No
Yes
Yes
Swimming pools and decks providing access to pools (see also § 155-10.10(E))
No
Yes
Yes
Steps and stairs (providing necessary access to an allowed building) up to 4 feet in height above grade
Yes
Yes
Yes
Wheelchair lifts and ramps that meet federal, state and local accessibility standards
Yes
Yes
Yes
 
   (G)   Building height.
      (1)   Measurement.  Building height is measured as the vertical distance from the finished grade to the highest point of the roof.
      (2)   Exceptions.
         (a)   General.  The following features are not counted in the measurement of building height and may exceed otherwise stated maximum height limits:
            1.   Chimneys,
            2.   Parapet walls,
            3.   Skylights,
            4.   Steeples,
            5.   Flag poles,
            6.   Smokestacks,
            7.   Cooling towers,
            8.   Elevator bulkheads,
            9.   Fore towers,
            10.   Monuments,
            11.   Water towers,
            12.   Stage towers or scenery lofts,
            13.   Tanks,
            14.   Ornamental towers and spires,
            15.   Mechanical appurtenances or penthouses to house mechanical appurtenances,
            16.   Cracking towers of refineries,
            17.   Power plants and electric substations.
            18.   Portions of a building elevated solely to comply with flood- proofing requirements.
         (b)   Solar energy systems.  Building- mounted solar energy systems may extend up to three feet above the applicable maximum zoning district height limit, provided they do not extend more than five feet above the roof line. See also § 155-10.10(F)(2).
         (c)   Public and civic buildings.  Public buildings, semi-public hospitals, institutions, schools, or public utility and service buildings may be erected to a height not exceeding 60 feet, provided that the building is set back from the street, rear, and side lot lines in addition to otherwise required district setbacks at least two additional feet for every one foot of building height above 40 feet.
      (3)   Federal Aviation Administration rules.
         (a)   No building or structure may be constructed that is subject to notice under Federal Aviation Regulations Par. 77, until it is determined by the Federal Aviation Administration not to be a hazard to aerial navigation.
         (b)   All petitions for zoning map amendments, special uses, variances, compensatory development rights, or planned unit developments, dealing with property located within two miles of any airport in Will County that is available for public use, must be forwarded to the Federal Aviation Administration for their review and comment. In addition, plans to construct any structure or building to a height exceeding 200 feet, regardless of location, must be forwarded to the Federal Aviation Administration for their review and comment.
         (c)   The Zoning Administrator must make available to the Federal Aviation Administrator any data relating to a petitioner's request to construct a building or structure within two miles of any airport in the county.
      (4)   Wireless telecommunication facilities.  Wireless telecommunications facilities are subject to the applicable height restrictions in § 155-9.270.
      (5)   Electric-generating wind devices.  Electric-generating wind devices are subject to the applicable height restrictions in § 155-9.260.
(Ord. effective 10-1-2012; Ord. 16-227, passed 12-15-2016; Ord. 18-1, passed 1-18-2018; Ord. 19-88, passed 4-18-2019)