ORDINANCE NO. BL2014-769

An Ordinance amending Chapters 17.04 and 17.16 of the Metropolitan Code to modify the definition and conditions of “Accessory dwelling, detached.” (Proposal No. 2014Z-007TX-002).

WHEREAS, detached accessory dwellings allow for more opportunities for a range of housing types;

WHEREAS, detached accessory dwellings maintain the existing lot pattern and allow for increased development options without teardowns;

WHEREAS, detached accessory dwellings allow for neighborhood scale infill while retaining the overall character of the neighborhood; and

WHEREAS, encouraging and fostering additional innovative housing choices and reinvestment in existing neighborhoods helps to enhance the quality of development for the citizens of Metropolitan Nashville and Davidson County.

NOW, THEREFORE, BE IT ENACTED BY THE COUNTY OF THE METROPOLITAN GOVERNMENT OF NASHVILLE AND DAVIDSON COUNTY:

Section 1. That Section 17.04.060 of the Metropolitan Code is hereby amended by deleting the definition of “Accessory dwelling, detached” and replacing with the following definition:

"Accessory dwelling, detached," also referred to as detached accessory dwelling, means a detached dwelling unit separate from the principal single-family structure on a lot located within a historic overlay district, within any urban design overlay with development standards for detached accessory dwellings, on any lot with an improved alley abutting the rear or side property line or on any lot over 15,000 square feet. The dwelling shall be clearly subordinate in size, height, and purpose to the principal structure, it shall be located on the same lot as the principal structure, but may be served by separate utility meter(s) and is detached from the principal structure. A detached accessory dwelling can be an independent structure or it can be a dwelling unit above a garage, or it can be attached to a workshop or other accessory structure on the same lot as the principal structure.

Section 2. That Section 17.16.030 of the Metropolitan Code is hereby amended by deleting subsection F.3. in its entirety and renumbering the remaining subsections.

Section 3. That Section 17.16.030 of the Metropolitan Code is hereby amended by deleting subsection F.6. Site Requirements in its entirety and replacing with the following:

Site Requirements. A detached accessory dwelling may only be located behind the principal structure.

Section 4. That Section 17.16.030 of the Metropolitan Code is hereby amended by deleting subsection F.7. Driveway Access in its entirety and replacing with the following:

Driveway Access.
a. On lots with no alley access, the lot shall have no more than one curb-cut from any public street for driveway access to the principal structure as well as the detached accessory dwelling.
b. On lots with alley access, any additional access shall be from the alley and no new curb cuts shall be provided from public streets.
c. Parking accessed from any public street shall be limited to one driveway for the lot with a maximum width of twelve feet.

Section 5. That Section 17.16.030 of the Metropolitan Code is hereby amended by deleting subsection F.8. Bulk and Massing in its entirety and replacing with the following:

Bulk and Massing.
a. The living space of a detached accessory dwelling shall not exceed seven hundred square feet.
b. On lots less than 10,000 square feet, the footprint of a detached accessory dwelling shall not exceed seven hundred fifty square feet
c. On lots 10,000 square feet or greater, the footprint of a detached accessory dwelling shall not exceed one thousand square feet.
d. The detached accessory dwelling shall maintain a proportional mass, size, and height to ensure it is not taller than the principal structure on the lot. The detached accessory dwelling height shall not exceed the height of the principal structure as measured to the eave line, with a maximum eave height of ten feet for single-story and seventeen feet for two-story detached accessory dwellings.
e. The roof ridge line of the detached accessory dwelling must be less than the primary structure and shall not exceed twenty seven feet in height.

Section 6. That Section 17.16.030 of the Metropolitan Code is hereby amended by deleting subsection F.9. Design Standards in its entirety and replacing with the following:

Design Standards.
a. The detached accessory dwelling shall be of similar style, design and material color as used for the principal structure and shall use similar architectural characteristics, including roof form and pitch, to the existing principal structure.
b. The detached accessory dwelling may have dormers that relate to the style and proportion of windows on the detached accessory dwelling and shall be subordinate to the roofslope by covering no more than fifty percent of the roof.
c. Detached accessory dwellings may have dormers that are setback a minimum of two feet from the exterior wall.
Section 7. That Section 17.16.030 of the Metropolitan Code is hereby amended by deleting subsection F.10. Metro Historic Zoning Commission Action in its entirety and replacing with the following:

Historic Properties.
a. Metro Historic Zoning Commission Action. Any existing or proposed detached accessory dwelling in a historic overlay district shall comply with the adopted regulations and guidelines of the applicable historic overlay.
b. Detached accessory dwellings with a second story dwelling unit shall enclose the stairs interior to the structure and properly fire rate them per the applicable life safety standards found in the code editions adopted by the Metropolitan Government of Nashville.

Section 8. That this Ordinance shall take effect five (5) days from and after its passage and such change be published in a newspaper of general circulation, the welfare of The Metropolitan Government of Nashville and Davidson County requiring it.

Sponsored by: Walter Hunt, Burkley Allen

LEGISLATIVE HISTORY
Introduced:	May 6, 2014
Passed First Reading:	May 6, 2014
Referred to:	Planning Commission - Approved 7-0 (April 10, 2014) Planning & Zoning Committee
Passed Second Reading:	June 3, 2014
Passed Third Reading:	June 17, 2014
Approved:	June 18, 2014
By:
Effective:	June 20, 2014