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File #: BL2021-620    Version: 1 Name:
Type: Bill (Ordinance) Status: Second Reading
File created: 1/26/2021 In control: Metropolitan Council
On agenda: 5/4/2021 Final action:
Title: An ordinance amending Chapters 17.36 and 17.40 of Title 17 of the Metropolitan Code to create a Detached Accessory Dwelling Unit (DADU) Overlay District. (Proposal No. 2021Z-002TX-001).
Sponsors: Burkley Allen, Sean Parker, Ginny Welsch, Freddie OConnell, Brett Withers, Brandon Taylor


An ordinance amending Chapters 17.36 and 17.40 of Title 17 of the Metropolitan Code to create a Detached Accessory Dwelling Unit (DADU) Overlay District. (Proposal No. 2021Z-002TX-001).


WHEREAS, the relative lack of affordable housing in the center-city of Nashville is an obstacle to living close to jobs and educational opportunities; and

WHEREAS, the fastest growing demographics in Nashville are in households without children, who frequently do not require a large dwelling unit; and

WHEREAS, NashvilleNext Plan envisions increased density along major corridors into and around the city while preserving the character of existing neighborhoods as the corridor housing transitions into the surrounding neighborhoods; and


WHEREAS, Public transit along these corridors is a more effective and environmentally friendly way to commute to work or other destinations, and can provide opportunities for residents to live without a car; and


WHEREAS, Many neighborhoods have downzoned from R to RS to reduce the economic pressure to demolish existing homes and replace them with two full size homes on a single lot; and


WHEREAS, Many homeowners in RS zoned areas have expressed a desire to add a detached structure to their home that can be used in a variety of ways, including for long-term rentals, that can be “neighborhood friendly” with a properly designed overlay; and


WHEREAS, a Detached Accessory Dwelling Unit can provide additional income allowing some homeowners to remain in their homes despite gentrification and rising costs; and


WHEREAS, Overlays are generally implemented with majority support of the affected neighbors, giving existing homeowners say in their housing opportunities and in their neighbors’ opportunities.




Section 1. That Chapter 17.36 of the Metropolitan Code is hereby amended by adding the following new Article XIV entitled “Detached Accessory Dwelling Unit (DADU) Overlay District”.


17.36.680 Purpose and intent.

 The DADU overlay district provides additional housing options in the Urban Zoning Overlay.


17.36.690 Overlay designation.

A DADU overlay district shall be created within the Urban Zoning Overlay according to the procedures of Chapter 17.40, Article III and depicted as a geographical area on the official zoning map.


17.36.700 Design guidelines.

A detached self-sufficient dwelling unit shall be allowed accessory to a principal structure subject to the standards set forth in Section 17.16.030.G of this zoning code.


17.36.710 Permitted land uses.

The range of land uses permitted within a DADU overlay district shall be those permitted by the underlying zoning district(s) as established by the zoning district land use table of Section 17.08.030 and accessory dwelling, detached. On any lot where a new accessory dwelling, detached is built, short term rental property, owner occupied, is not a permitted use in the accessory dwelling unit. 


17.36.720 Bulk Provisions.

The bulk provisions of the base zoning district shall apply.


17.36.730 Detached Accessory Dwelling Unit Overlay District.

A.                     Application of a DADU overlay.

1.                     A DADU overlay shall consist of a minimum of 30 contiguous lots. For the purposes of this overlay, lots on opposing block faces and opposite sides of alleys shall be considered contiguous.

2.                     A DADU overlay shall be bounded on all sides by streets, alleys, railroads, rivers or other separations so that no lot lines are shared with properties that are not in the overlay district.

B.                      Planning Commission Recommendation. The planning commission shall review a proposed DADU overlay district application for conformance with the General Plan. The planning commission shall act to recommend approval or disapproval of the application. Within ten working days of an action, the commission's resolution shall be transmitted in writing to the applicant, the metro clerk, the zoning administrator and all other appropriate governmental departments.

C.                      Council Consideration. The metropolitan council shall consider an ordinance establishing a DADU overlay district according to the procedures of Article III of this chapter (Amendments). All property owners within and proximate to a proposed DADU overlay district shall be notified according to the procedures of Article XV of this chapter.

D.                     Final Site Plan Approval. For property located within a DADU overlay district, a final site plan application shall be submitted for review and approval by the Zoning Administrator in a manner consistent with the procedures of Section 17.40.170A. The applicant is required to submit all necessary information to the Zoning Administrator and to certify the accuracy of the submitted information.

E.                      Changes to a DADU Overlay District Boundary. A proposed change in the geographic boundary of a DADU overlay district on the official zoning map shall be considered by the council according to the procedures of Article III of this chapter (Amendments).


Section 2. Section 17.40.740 of the Metropolitan Code is hereby amended by deleting subsection C.3 in its entirety and substituting with the following:


“Applying the urban design overlay district, historic preservation district, neighborhood conservation district, urban zoning overlay district, contextual overlay district, corridor design overlay district, detached accessory dwelling unit overlay district, or detached accessory dwelling unit overlay district as provided in Chapter 17.36;”


Section 3. 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.


Agenda Analysis



This ordinance, as amended, creates a Detached Accessory Dwelling Unit (DADU) Overlay District in Title 17 of the Metropolitan Code.


The proposed overlay would permit a detached, self-sufficient dwelling unit accessory to a principal structure. The overlay would permit DADUs within the boundary of the overlay, subject to existing standards for detached accessory dwelling units in Section 17.16.030.G of Title 17. These standards include requirements for, but not limited to, ownership, lot area, setbacks, bulk & massing, design, and access. This ordinance does not apply the overlay to any areas; it only creates the tool that can be utilized. The process to apply the overlay is the same process as a rezoning and is similar to the process for other overlays, such as contextual overlays and residential accessory structure overlays.


An amendment added at the March 3 meeting clarifies that a DADU overlay is only applicable to properties zoned RS/RS-A or properties where a DADU is a legally permitted use prior to the establishment of the overlay. Further, properties within a DADU overlay cannot share lot lines with single-family residentially zoned properties that are not in the overlay district.


This ordinance was approved by the Planning Commission.