ACCESSORY BUILDINGS AND STRUCTURES ON LOTS USED EXCLUSIVELY FOR RESIDENTIAL AND MIXED-USE PURPOSES.
Madison General Ordinances § 28.131
in effect28.131 - ACCESSORY BUILDINGS AND STRUCTURES ON LOTS USED EXCLUSIVELY FOR RESIDENTIAL AND MIXED-USE PURPOSES.
(1) All accessory buildings and structures on lots in any district used exclusively for residential and mixed-use purposes shall comply with the following requirements:
(a) Maximum Area Per Lot. Total area of accessory buildings measured at ground floor may not exceed one thousand (1,000) square feet. A larger total building area may be allowed by conditional use approval. The footprint of accessory structures that contain accessory dwelling units shall not be included in the one thousand (1,000) square feet calculation. (Am. by ORD-25-00068, 10-16-25)
(b) Maximum Height. The height of the principal building or fifteen (15) feet, whichever is lower. The following are exempt from this requirement:
1. The maximum height of accessory dwelling units shall be determined by the district requirements for zoning districts where such units are allowed.
2. The maximum height of carriage houses within historic district may be the same as the original height.
(c) Reserved. (Rpld by ORD-18-00049, 5-14-18)
(d) Placement. Accessory buildings may be located in the following locations:
1. Within the building envelope.
2. In a rear yard setback, a minimum of three (3) feet from any property line.
3. In a side yard setback, if located behind the rear plane of the principal building at the time of construction, a minimum of three (3) feet from any property line.
4. In the side or rear yard setback of a corner lot, a minimum distance from the street side lot line equal to the setback required for a principal building in the district.
5. In the rear yard setback of a reversed corner lot, no closer to the street side lot line than the front yard setback of the adjacent property, for the first twenty-five (25) feet from the common property line. Beyond this distance, the minimum setback shall be equal to the setback required for a principal building in the district.
6. A minimum of three (3) feet from any principal building and any other accessory building. (Cr. by ORD-13-00007, 1-15-13)
Figure I1: Accessory Building Placement Accessory buildings may be located in shaded areas.
[image omitted; see the official code]
[image omitted; see the official code]
[image omitted; see the official code]
Figure I3: Accessory Building Placement for Reverse Corner Lots. Accessory buildings may be located in shaded areas.
(e) Shared Garages. A detached garage may be constructed across a lot line by abutting property owners, where a garage is permitted within three (3) feet of the lot line, provided that:
1. A joint driveway shall lead to the garage; and
2. The property owners shall provide a joint access and maintenance agreement for the use of the garage.
(f) Side and Rear Yard Garage Replacement. A detached garage located in a side or rear yard may be replaced within the existing setbacks provided that:
1. The garage is replaced within one (1) year of demolition.
2. The location and size of the existing or demolished garage shall be verified by the Zoning Administrator.
3. The replaced garage shall not exceed twenty-four (24) feet in length or width.
4. Neither the length, width, nor height of the replaced garage shall be more than two (2) feet greater than the length, width, or height of the demolished garage.
5. No side of the enlarged structure is moved closer to any lot line with which there is a non-conforming setback.
6. Reserved. (Rpld. by ORD-24-00001, 1-17-24)
(g) Garages in Embankments in Front Yards. Where the mean natural grade of a front yard is more than eight (8) feet above curb level, a private garage may be erected within the front yard setback, provided that:
1. The garage shall be located at least five (5) feet from the front lot line; and
2. At least one-half (½) of the height of the garage shall be below the mean grade of the front yard.
(2) Reserved for Future Use. (Rep. by ORD-15-00116, 10-28-15)
(Am. by ORD-13-00007, 1-15-13) (Am. by ORD-21-00087, 12-15-21)
Source: City of Madison, Wisconsin, Madison General Ordinances (Municode Library, library.municode.com)URL: https://library.municode.com/wi/madison/codes/code_of_ordinances?nodeId=COORMAWIVOIICH20--31_CH28ZOCOOR_SUBCHAPTER_28IGERE_28.131ACBUSTLOUSEXREMIEPUFetched: 11/1/2026