17-3-0400 Bulk and density standards.

   17-3-0401 General. Bulk and density standards in the "B" and "C" districts vary according to the applicable bulk and density designation. Bulk and density designations are indicated by the numeral following the dash (–) in the district name, as in "B1-2" (B1 dash 2).

   17-3-0402-A Standards. Where allowed, all residential development in B and C districts is subject to the following minimum lot-area-per-unit standards:

 

District	Minimum Lot Area per Unit (square feet)
	Per Dwelling Unit	Per Efficiency Unit	Per SRO Unit
Dash 1	2,500	2,500	Not Allowed
Dash 1.5	1,350	1,350	Not Allowed
Dash 2	1,000	700	700
Dash 3	400	300	200
Dash 5	200	135	100

 

(See Sec. 17-17-0304 for rules governing the measurement of lot area per unit.)

   17-3-0402-B MLA Reduction for Transit-Served Locations. All projects in B-3 and C-3 districts located within 2,640 feet of a CTA or METRA rail station entrance or exit or within 1,320 feet of a CTA bus line corridor roadway segment listed in Table 17-17-0400-B and which are in compliance with Section 17-3-0308 are eligible to use the reduced lot area per unit standards as established in the table below. These minimum lot area reductions are allowed only if the project is reviewed and approved in accordance with the Type I Zoning Map Amendment procedures of Section 17-13-0302, or the planned development procedures of Section 17-13-0600 (if the project qualifies as a mandatory or elective planned development under Sections 17-8-0500 or 17-8-0600):

 

District	Proportion of ARO requirement on-site per 2-44-085 (Must include a minimum of one affordable unit under 2-44-085)	Minimum Lot Area per Unit (square feet)
		Per Dwelling Unit	Per Efficiency Unit	Per SRO Unit
Dash 3	50%	350	250	180
	75%	325	225	160
	100%	300	200	135

 

   17-3-0403 Floor Area Ratio.

      17-3-0403-A Standards. All development in B and C districts is subject to the following maximum floor area ratio standards:

 

District	Maximum Floor Area Ratio
Dash 1	1.2
Dash 1.5	1.5
Dash 2	2.2
Dash 3	3.0
Dash 5	5.0

 

(See Sec. 17-17-0305 for rules governing the measurement of floor area ratio.)

      17-3-0403-B FAR Increase for Transit- Served Locations. All projects in B-3 and C-3 districts located within 2,640 feet of a CTA or METRA rail station entrance or exit or within 1,320 feet of a CTA bus line corridor roadway segment listed in Table 17-17-0400-B and which are in compliance with Section 17-3-0308 may increase the maximum floor area ratio standard as established in the table below. This floor area ratio increase is allowed only if the project is reviewed and approved in accordance with the Type 1 Zoning Map Amendment procedures of Section 17-13-0302, or the planned development procedures of Section 17-13-0600 (if the project qualifies as a mandatory or elective planned development under Sections 17-8-0500 or 17-8-0600).

 

District	Proportion of ARO requirement on-site per 2-44-085-G	Maximum Floor Area Ratio
Dash 3	50%	3.5
	75%	3.75
	100%	4

 

   17-3-0404 Front Setbacks. No front setback is required in B or C districts, except on B- or C-zoned lots abutting R-zoned lots that have lot frontage on the same street. The required front setback in those cases must equal at least 50% of the front yard that exists on the abutting R-zoned lot. If the abutting R-zoned lot is vacant, the 50% must be calculated on the basis of the abutting lot's required front setback. (See Sec. 17-17-0306 for rules governing the measurement of front setbacks.)

   17-3-0405 Rear Setbacks. All development in B and C districts is subject to the following minimum rear setback standards:

      17-3-0405-A For floors containing dwelling units, the minimum rear setback is 30 feet. This does not apply to existing buildings where there is a change of use or interior alterations and where there are no additions to the existing structure which are proposed within the rear setback. (See Sec. 17-17-0307 for rules governing the measurement of rear setbacks.)

      17-3-0405-B For floors without dwelling units:

         1.   When the rear property line of B- or C-zoned property abuts a side property line of R-zoned property, a rear setback is required on the B- or C- zoned property that is equal in dimension to the minimum side setback required for a residential building on the adjacent R-zoned lot.

         2.   When the rear property line of B- or C-zoned property abuts a rear property line of R-zoned property, the minimum rear setback for the B- or C- zoned property is 16 feet. In such cases, the rear setback may begin 15 feet or one story above grade, whichever is lower.

   17-3-0406 Side Setbacks. No side setbacks are required in B and C districts, except when B- or C- zoned property abuts R-zoned property, in which case the side setback required for a residential use on the R- zoned lot applies. Townhouse developments, where allowed, are subject to the townhouse development standards of Sec. 17-2-0500. (See Sec. 17-17-0308 for rules governing the measurement of side setbacks.)

      17-3-0406-A Reversed Corner Lot Setback Standards. In all B and C districts, the minimum side setback on a reversed corner lot must be equal to at least 50% of the front yard that exists on any R-zoned lot abutting the rear of the reversed corner lot. If the abutting R-zoned lot to the rear is vacant, the 50% is to be calculated on the basis of the abutting lot's required front setback. Moreover, no accessory building on a reverse corner lot may be located within 5 feet of any part of a rear lot line that coincides with a side lot line of property in an RS1, RS2, or RS3 district.

Figure 17-3-0406-A

   17-3-0407 Building (Wall) Separation.

      17-3-0407-A Purpose; Applicability. The building separation standards of this section are intended to ensure adequate separation between exterior building walls that serve as a primary source of natural light and air for dwelling units. These standards apply to courtyard buildings, buildings with car courts, or other developments when dwelling units face or are adjacent to one another. Townhouse developments are exempt from these standards; they are subject to the standards of Sec. 17-2-0500.

      17-3-0407-B General. Unless otherwise expressly stated, exterior building walls are subject to the minimum setback standards of the underlying zoning district.

      17-3-0407-C Front and Rear Walls.

         1.   Facing Interior Side Property Line. When a front wall faces the subject property's interior side property line, the wall must be setback from the interior side property line a distance equal to at least 12 feet, or in the case of a rear wall, a distance equal to at least 10% of the lot width or 12 feet, whichever is less. (See Sec. 17-17-0310 for rules governing the measurement of building wall separation.)

         2.   Facing Other Front or Rear Walls. When the front wall or rear wall of a dwelling unit faces the front wall or rear wall of another dwelling unit located on the same zoning lot, the minimum required separation between such walls is as follows:

 

District	Minimum Separation (feet)
Dash 1	30
Dash 1.5	30
Dash 2	30
Dash 3	30
Dash 5	26

 

      17-3-0407-D End Walls Facing Front or Rear Walls. When the end wall of a dwelling unit faces the front wall or rear wall of a dwelling unit located on the same zoning lot, the minimum required separation between such walls is 20 feet.

   17-3-0408 Building Height.

      17-3-0408-A Standards. Maximum building height limits in B and C districts vary by building type and lot frontage, as follows:

District	Maximum Building Height (feet)
	Lot frontage of 25 feet or less	Lot frontage of more than 25 and less than 50 feet	Lot frontage of 50 to 99.9 feet	Lot frontage of 100 feet or more
Buildings with Ground-floor Commercial Space that complies with Sec. 17-3-0305
Dash 1	38	38	38	38
Dash 1.5	38	38	38	38
Dash 2	47	50	50	50
Dash 3	50	55	65	65
Dash 5	50	55	70	80 [1]
Buildings without Ground-floor Commercial Space that complies with Sec. 17-3-0305
Dash 1	38	38	38	38
Dash 1.5	38	38	38	38
Dash 2	45	45	45	45
Dash 3	50	50	60	60
Dash 5	50	50	65	75 [1]

 

Notes: See Sec. 17-17-0311 for rules governing the measurement of building height.

On lots with multiple lot frontages, allowable building height must be based on the shortest lot frontage.

[1]   Buildings may exceed the maximum height standard applicable to 100+-foot lots in dash 5 districts only if reviewed and approved in accordance with the Planned Development procedure of Sec. 17-13-0600; no minimum land area standard applies to projects seeking such PD approval.

      17-3-0408-B Building Height Increase for Transit-Served Locations. 

         1.   All projects in B-3 and C-3 districts located within 2,640 feet of a CTA or METRA rail station entrance or exit or within 1,320 feet of a CTA bus line corridor roadway segment listed in Table 17-17-0400-B and which are in compliance with Section 17-3-0308 are eligible for increases in maximum building height as established in the table below. These building height increases are allowed only if the project is reviewed and approved in accordance with the Type I Zoning Map Amendment procedures of Section 17-13-0302, or the planned development procedures of Section 17-13-0600 (if the project qualifies as a mandatory or elective planned development under Sections 17-8-0500 or 17-8-0600).

         2.   All projects in B dash 3 and C dash 3 districts subject to Sec. 2-45-115 that (a) qualify for and are granted a building height increase under Sec. 17-3-0408-B.1 above, and (b) provide at least 50% of the required affordable units on-site, are eligible for additional increases in maximum building height as established in the table below. These building height increases are allowed only if the project is reviewed and approved in accordance with the Type I Zoning Map Amendment procedures of Sec. 17-13-0302, or the planned development procedures of Sec. 17-13-0600 (if the project qualifies as a mandatory or elective planned development under Sections 17-8-0500 or 17-8-0600).

District	Maximum Building Height (feet)
	Lot frontage of 25 feet or less	Lot frontage of more than 25 and less than 50 feet	Lot frontage of 50 to 99.9 feet	Lot frontage of 100 feet or more
Buildings with Ground-Floor Commercial Space that Complies with Section 17-3-0305
Dash 3	50	55	70	75 [1]
Dash 3 - with at least 50% Section 2-44-080 Units	55	60	75	80 [1]
Buildings without Ground-Floor Commercial Space that Complies with Section 17-3-0305
Dash 3	50	50	65	70 [1]
Dash 3 - with at least 50% Section 2-44-080 Units	55	55	70	75 [1]

 

[1]   Buildings may exceed the maximum building height standard applicable to 100+ foot lots in dash 3 districts only if reviewed and approved in accordance with the planned development procedure of Section 17-13-0600; no minimum land area standard applies to projects seeking such PD approval.

      17-3-0408-C Exemption for Wrigley Field Adjacent Area. The building height limits of Sec. 17-3-0408 do not apply to residential construction in the "Wrigley Field Adjacent Area", as defined in Chapter 4-388 of the Municipal Code.

   17-3-0409 Average Dwelling Unit Size. The gross residential floor area developed on a lot divided by the total number of dwelling units on such lot may not be less than 500 square feet. No existing residential use may be converted to conflict with or further conflict with this standard.

   17-3-0410 Number of Efficiency Units.

      17-3-0410-A Standards. In B and C districts the total number of efficiency units may not exceed the following standards except as specified in Sec. 17-3-0410-B:

 

District	Maximum Number of Efficiency Units (% of total units)
Dash 1	10
Dash 1.5	15
Dash 2	20
Dash 3	20
Dash 5	30

 

      17-3-0410-B Exemption. 

         1.   The limits on efficiency units do not apply to elderly housing developments, provided that the Zoning Administrator determines that such developments constitute bona fide elderly housing developments.

         2.   The limits on efficiency units do not apply to transit-served developments within 660 feet of a CTA or METRA rail station entrance or exit or a CTA bus line corridor roadway segment listed in Table 17-17-0400-B.

(Added Coun. J. 5-26-04, p. 25275; Amend Coun. J. 3-9-05, p. 44391; Amend Coun. J. 9-13-06, p. 84870, § 2; Amend Coun. J. 11-8-12, p. 38872, § 243; Amend Coun. J. 9-11-13, p. 60173, §§ 1 – 3; Amend Coun. J. 3-18-15, p. 105476, §§ 3, 4; Amend Coun. J. 9-24-15, p. 7499, §§ 1 – 4; Amend Coun. J. 1-23-19, p. 94981, § 1; Amend Coun. J. 4-21-21, p. 29627, § 6; Amend Coun. J. 7-20-22, p. 50878, § 4; Amend Coun. J. 1-18-23, p. 59796, § 4)