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An ordinance amending Title 17 of the Metropolitan Code of Laws, to add various new data center uses and related definitions and conditions to the Zoning Code (Proposal No. 2026Z-012TX-001).
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BE IT ENACTED BY THE COUNCIL OF THE METROPOLITAN GOVERNMENT OF NASHVILLE AND DAVIDSON COUNTY:
Section 1. That Section 17.04.060 of the Metropolitan Code is hereby amended by adding the following new definitions in alphabetical order:
“Closed loop system” means a system that constantly reuses and recycles an initial load of water within its operation, reducing the draw on external water sources and minimizing wastewater discharge. A closed loop system shall not use evaporative cooling, and may consist of methods including, but not limited to, air-cooled (dry) cooling, rear-door heat exchanger cooling, hybrid dry economizer cooling, direct-to-chip cooling, or immersion cooling.
"Data center" means a physical room, building, or facility primarily used for housing and operating computer systems and associated equipment, including servers, data storage and processing systems, and accessory infrastructure such as cooling systems, power generators, electrical substations, and network hardware. Data center includes “data center - accessory”, “data center - small”, “data center - medium”, “data center - large”, and “data center - campus”. The square footage of a data center shall include the total square footage of each floor in the data center development, the square footage of any supporting uses, and the square footage of any additional exterior equipment, such as substations, electrical yards, mechanical yards, and all other exposed equipment, located within the property boundaries.
“Data center - accessory” means a data center of 5,000 square feet in size or less that has a maximum utilization capacity of 1MW of electricity and is accessory to another principal use. The principal use shall utilize more square footage than the data center.
“Data center - campus” means a geographically contiguous development of one or multiple buildings utilized as a data center and all associated supporting structures and uses, including a dedicated power substation, built across one or multiple phases totaling at least 500,000 square feet and/or has a maximum utilization capacity greater than 100MW. This use shall not be permitted in Davidson County.
“Data center - large” means a data center between 100,000 and 499,000 square feet in size and/or has a maximum utilization capacity between 20MW and 100MW of electricity and utilizes a dedicated power substation.
“Data center - medium” means a data center between 20,000 and 99,000 square feet in size and/or has a maximum utilization capacity between 5MW and 20MW of electricity and may utilize a dedicated power substation.
“Data center - small” means a data center of 20,000 square feet in size or less and/or has a maximum utilization capacity of 5MW of electricity and does not utilize a dedicated power substation. Data center - small uses may be located in mixed use structures that do not contain residential units provided that the data center makes up less than thirty percent (30%) of the total square footage of the building.
“Load” means the total power consumed by servers, storage, cooling, ventilation, generators, and other networking devices that operate within a data center.
“Megawatt (MW)” means the unit of measurement for electricity that is equivalent to one million watts.
Section 2. That Section 17.08.030 of the Metropolitan Code is hereby amended by adding the following to the Zoning District Land Use Table: "Data center - accessory" as an industrial use permitted as accessory (A) in the MUG, MUI, OG, ORI, CS, CF, DTC North, DTC South, DTC West, DTC Central, DTC East, SCR, IWD, IR, and IG zoning districts; “Data center - small” as an industrial use permitted with conditions (PC) in the CS, CF, DTC South, DTC West, DTC Central, IWD, IR, and IG zoning districts; “Data center - medium” as an industrial use permitted with conditions (PC) in the IWD, IR, and IG zoning districts; “Data center - large” as an industrial use permitted by special exception (SE) in the IR and IG zoning districts; and “Data center - campus” as an industrial use not permitted in any zoning district.
Section 3. That Section 17.16.090 of the Metropolitan Code is hereby amended by adding the following as a new Subsections C, D, and E and redesignating the existing Subsection C and subsequent subsections:
C. Data Center - Small.
1. Location. No data center shall be permitted on a parcel within one hundred linear feet of a parcel containing a residential use, daycare home, daycare center, religious institution, community education use, park, zoo, or other data center.
2. Buffer yards. Buffer yard standards shall comply with the provisions of Chapter 17.24 of the Metropolitan Code.
3. Design standards for data centers not incorporated within a mixed-use building.
a. When within 300 feet of a publicly accessible road or right-of-way, a minimum of thirty percent (30%) of the width of the front façade at the ground level of any building shall consist of fenestration.
b. A minimum of thirty percent (30%) of the width of the side and rear facades shall incorporate decorative faux windows, architecturally glazed windows, or other decorative treatment.
c. Building façades oriented towards a public right-of-way or a parcel zoned a non-industrial zoning district shall be constructed of brick, brick veneer, stone, cast stone, cementitious siding, glass, or materials substantially similar in form and function. The Zoning Administrator may waive this requirement if the building façade is not visible from the adjacent parcel or the public right-of-way.
d. Rooftop mechanical equipment, including but not limited to heating, air conditioning, ventilation, generators, and similar equipment, shall not exceed a height of thirty feet as measured from the base of the equipment. Such equipment shall be screened to fully conceal the mechanical equipment from the adjacent roadways and properties and from the site itself. No screening shall be required for renewable energy infrastructure or for green infrastructure, such as green roofs, rooftop cisterns, and other bioretention equipment.
e. Building height for any data center shall not exceed 75’ in height or the maximum allowed height permitted in the applicable zoning district the data center is located within, whichever is more restrictive. Any applicable height control planes shall also apply.
4. Operation standards.
a. There shall be no light trespass from the site onto surrounding properties, including any right-of-way.
b. All cooling and ventilation equipment shall operate on a closed-loop system.
c. Cooling, ventilation, and other external equipment shall not be located between the primary data center building and a public right-of-way, unless located on the rooftop of a data center building.
d. Excluding generator testing or commissioning activities, emissions producing electrical generation shall be for backup and emergency use only. Operation of such generators shall be limited to no more than seventy-two hours consecutively. This subsection shall not apply to the use of renewable energy sources including, but not limited to solar panels, small wind energy facilities, and waste heat recovery.
e. Any emissions producing electrical generators on the property shall comply with U.S. Environmental Protection Agency (EPA) New Source Performance Standards (NSPS) for at least Tier 4 emission standards.
i. Testing for these generators shall not exceed 10 hours per month.
ii. Testing for these generators shall only occur between the hours of 9:00 a.m. and 5:00 p.m.
iii. Generators shall be fully enclosed within a sound attenuation wall for noise reduction and to reduce pollution.
iv. A generator testing log demonstrating compliance with these standards shall be maintained and furnished to the Zoning Administrator or their designee upon request.
f. Maximum permissible sound levels shall not exceed sixty-five (65) decibels (dB) during the daytime (7:01 a.m. to (9:59 p.m.) and fifty-five (55) decibels (dB) during the nighttime (10:00 p.m. to 7:00 a.m.) as measured from any property line.
D. Data Center - Medium.
1. Location. No data center shall be permitted on a parcel within five hundred linear feet of a parcel containing a residential use, daycare home, daycare center, religious institution, community education use, park, zoo, or other data center.
2. Buffer yards. Where a data center is located on a parcel adjacent to a non-industrial zone district, there shall be screening in the form of landscape buffer yard Standard D applied along common property lines.
3. Design standards.
a. When within 300 feet of a publicly accessible road or right-of-way, a minimum of thirty percent (30%) of the width of the front façade at the ground level of any building shall consist of fenestration.
b. A minimum of ten percent (10%) of the width of the side and rear facades shall incorporate decorative faux windows, architecturally glazed windows, or other decorative treatment.
c. Building façades oriented towards a public right-of-way or a parcel zoned a non-industrial zoning district shall be constructed of brick, brick veneer, stone, cast stone, cementitious siding, glass, or materials substantially similar in form and function. The Zoning Administrator may waive this requirement if the building façade is not visible from the adjacent parcel or the public right-of-way.
d. Rooftop mechanical equipment, including but not limited to heating, air conditioning, ventilation, generators, and similar equipment, shall not exceed a height of thirty feet as measured from the base of the equipment. Such equipment shall be screened to fully conceal the mechanical equipment from the adjacent roadways and properties and from the site itself. No screening shall be required for renewable energy infrastructure or for green infrastructure, such as green roofs, rooftop cisterns, and other bioretention equipment.
e. Building height for any data center shall not exceed 75’ in height or the maximum allowed height permitted in the applicable zoning district the data center is located within, whichever is more restrictive. Any applicable height control planes shall also apply.
4. Operation standards.
a. Substations, electrical yards, mechanical yards, and any other exposed equipment shall not be located between the primary structure and a public road or right-of way and shall be fully screened from all adjacent parcels and rights-of-way.
b. There shall be no light trespass from the site onto surrounding properties, including any right-of-way.
c. All cooling and ventilation equipment shall operate on a closed-loop system.
d. Cooling, ventilation, and other external equipment shall not be located between the primary data center building and a public right-of-way, unless located on the rooftop of a data center building.
e. Substations associated with the operation of a data center shall only be permitted in the IWD, IR, and IG zoning districts, and shall be located at least fifty feet from any public right-of-way or adjacent parcel. Vehicle storage and service equipment shall not be collocated with the substation.
f. Excluding generator testing or commissioning activities, emissions producing electrical generation shall be for backup and emergency use only. Operation of such generators shall be limited to no more than seventy-two hours consecutively. This subsection shall not apply to the use of renewable energy sources including, but not limited to solar panels, small wind energy facilities, and waste heat recovery.
g. Any emissions producing electrical generators on the property shall comply with U.S. Environmental Protection Agency (EPA) New Source Performance Standards (NSPS) for at least Tier 4 emission standards.
i. Testing for these generators shall not exceed 10 hours per month.
ii. Testing for these generators shall only occur between the hours of 9:00 a.m. and 5:00 p.m.
iii. Generators shall be fully enclosed within a sound attenuation wall for noise reduction and to reduce pollution.
iv. A generator testing log demonstrating compliance with these standards shall be maintained and furnished to the Zoning Administrator or their designee upon request.
h. Maximum permissible sound levels shall not exceed sixty-five (65) decibels (dB) during the daytime (7:01 a.m. to (9:59 p.m.) and fifty-five (55) decibels (dB) during the nighttime (10:00 p.m. to 7:00 a.m.) as measured from any property line.
Section 4. That Section 17.16.185 of the Metropolitan Code is hereby amended by adding the following as a new Subsection A and redesignating the existing Subsection A and subsequent subsections:
A. Data Center - Large.
1. Location. No data center shall be permitted on a parcel within two thousand six hundred and forty linear feet of a parcel containing a residential use, daycare home, daycare center, religious institution, community education use, park, zoo, or other data center.
2. Buffer yards. There shall be screening in the form of landscape buffer yard Standard D-1 plus an eight foot tall masonry wall applied along all property lines of the parcel(s) containing the data center use.
3. Design standards.
a. When within 300 feet of a publicly accessible road or right-of-way, a minimum of thirty percent (30%) of the width of the front façade at the ground level of any building shall consist of fenestration.
b. A minimum of ten percent (10%) of the width of the side and rear facades shall incorporate decorative faux windows, architecturally glazed windows, or other decorative treatment.
c. Building façades oriented towards a public right-of-way or a parcel zoned a non-industrial zoning district shall be constructed of brick, brick veneer, stone, cast stone, cementitious siding, glass, or materials substantially similar in form and function. The Zoning Administrator may waive this requirement if the building façade is not visible from the adjacent parcel or the public right-of-way.
d. Rooftop mechanical equipment, including but not limited to heating, air conditioning, ventilation, generators, and similar equipment, shall not exceed a height of thirty feet as measured from the base of the equipment. Such equipment shall be screened to fully conceal the mechanical equipment from the adjacent roadways and properties and from the site itself. No screening shall be required for renewable energy infrastructure or for green infrastructure, such as green roofs, rooftop cisterns, and other bioretention equipment.
e. Building height for any data center shall not exceed 75’ in height or the maximum allowed height permitted in the applicable zoning district the data center is located within, whichever is more restrictive. Any applicable height control planes shall also apply.
f. If a data center includes the use of renewable energy sources to offset at least fifty percent (50%) of a data center’s total energy usage, the building height for the data center shall be permitted to increase to a maximum of one hundred fifty (150) feet if such additional height conforms to the permitted height and height control plane of the applicable zoning district the data center is located within. Renewable energy sources may consist of solar panels, on-site solar farm, small wind energy facilities, waste heat recovery, and other renewable energy sources.
4. Operation standards.
a. Substations, electrical yards, mechanical yards, and any other exposed equipment shall not be located between the primary structure and a public right-of way and shall be fully screened from all adjacent parcels and rights-of-way.
b. There shall be no light trespass from the site onto surrounding properties, including any right-of-way.
c. All cooling and ventilation equipment shall operate on a closed-loop system.
d. Cooling, ventilation, and other external equipment shall not be located between the primary data center building and a public road or right-of-way, unless located on the rooftop of a data center building.
e. Substations associated with the operation of a data center shall only be permitted in the IR and IG zoning districts, and shall be located at least fifty feet from any public right-of-way or adjacent parcel. Vehicle storage and service equipment shall not be collocated with the substation.
f. Excluding generator testing or commissioning activities, emissions producing electrical generation shall be for backup and emergency use only. Operation of such generators shall be limited to no more than seventy-two hours consecutively. This subsection shall not apply to the use of renewable energy sources including, but not limited to solar panels, small wind energy facilities, and waste heat recovery.
g. Any emissions producing electrical generators on the property shall comply with U.S. Environmental Protection Agency (EPA) New Source Performance Standards (NSPS) for at least Tier 4 emission standards.
i. Testing for these generators shall not exceed 10 hours per month.
ii. Testing for these generators shall only occur between the hours of 9:00 a.m. and 5:00 p.m.
iii. Generators shall be fully enclosed within a sound attenuation wall for noise reduction and to reduce pollution.
iv. A generator testing log demonstrating compliance with these standards shall be maintained and furnished to the Zoning Administrator or their designee upon request.
h. Maximum permissible sound levels shall not exceed sixty-five (65) decibels (dB) during the daytime (7:01 a.m. to (9:59 p.m.) and fifty-five (55) decibels (dB) during the nighttime (10:00 p.m. to 7:00 a.m.) as measured from any property line.
Section 5. That Section 17.16.300 of the Metropolitan Code is hereby amended by adding the following as a new Subsection A and redesignating the existing Subsection A and subsequent subsections:
A. Data Center - Accessory.
1. Location. Data center - accessory uses shall be fully located within the same structure containing the principal use.
2. Operation standards.
a. All cooling and ventilation equipment shall operate on a closed-loop system.
b. Cooling, ventilation, and other external equipment shall not be located between the building containing the data center and a public right-of-way.
c. Excluding generator testing or commissioning activities, emissions producing electrical generation shall be for backup and emergency use only. Operation of such generators shall be limited to no more than seventy-two hours consecutively. This subsection shall not apply to the use of renewable energy sources including, but not limited to solar panels, small wind energy facilities, and waste heat recovery.
d. Any emissions producing electrical generators on the property shall comply with U.S. Environmental Protection Agency (EPA) New Source Performance Standards (NSPS) for at least Tier 4 emission standards.
i. Testing for these generators shall not exceed 10 hours per month.
ii. Testing for these generators shall only occur between the hours of 9:00 a.m. and 5:00 p.m.
iii. Generators shall be fully enclosed within a sound attenuation wall for noise reduction and to reduce pollution.
iv. A generator testing log demonstrating compliance with these standards shall be maintained and furnished to the Zoning Administrator or their designee upon request.
e. Maximum permissible sound levels shall not exceed sixty-five (65) decibels (dB) during the daytime (7:01 a.m. to (9:59 p.m.) and fifty-five (55) decibels (dB) during the nighttime (10:00 p.m. to 7:00 a.m.) as measured from any property line.
Section 6. That Table 17.20.030 of the Metropolitan Code is hereby amended by adding the following as industrial uses in alphabetical order: “Data center - small” requiring a minimum of 1 space per employee, plus 1 space per 5,000 square feet; “Data center - medium” requiring a minimum of 1 space per employee, plus 1 space per 5,000 square feet; “Data center - large” requiring 1 space per employee plus 1 space per 10,000 square feet; “Data center - campus” requiring 1 space per employee plus 1 space per 15,000 square feet.
Section 7. That Chapter 17.40 of the Metropolitan Code is hereby amended by adding a new Section 17.40.575 as follows:
17.40.575 - Permits for data centers.
The application requirements for zoning permits for any data center use shall include the following in addition to all requirements of Section 17.40.530 of this code:
A. The developer shall provide written confirmation at the time of application for a zoning permit that Nashville Electric Service (NES) has reviewed the proposed data center and agreed to provide electric service to the data center. No zoning permit shall be approved if NES has not agreed to provide electric service.
B. The developer shall provide written confirmation at the time of application for a zoning permit that the utility providing water and sewer service to the site has reviewed the proposed data center and has determined that there is adequate capacity to service the data center. No zoning permit shall be approved if the applicable utility has determined that there is insufficient water and/or sewer capacity to service the data center.
C. A noise impact assessment shall be required as part of the zoning permit application and shall be assessed at a distance of 500 feet from the property line of the parcel(s) containing the data center. The noise impact assessment shall:
1. Define the scope of the assessment, including the geographic area, the noise sources to be studied, and the specific objectives of the assessment.
2. Measure pre-operation ambient noise, existing background noise, and provide acoustic mitigation strategies to ensure the post construction noise levels do not exceed sixty-five (65) decibels (dB) during the daytime (7:01 a.m. to 9:59 p.m.) and fifty-five (55) decibels (dB) during the nighttime (10:00 p.m. to 7:00 a.m.) as measured from all property lines.
D. A water consumption and sustainability plan addressing conservation and scarcity, outlining the total water requirement of the data center, including cooling needs, and any strategies to reduce or mitigate excessive water usage shall be submitted prior to approval of the zoning permit. The plan shall demonstrate that water usage will not significantly strain the local and regional water supply. The water consumption and sustainability plan shall specifically demonstrate or identify:
1. The vulnerability of the project and project site to water scarcity and drought.
2. Anticipated disturbances of public services, including but not limited to transport, communication, sanitation, fresh water, and electricity supply.
3. Any drought monitoring and forecasting systems that exist in the project area.
4. Proposed water scarcity/drought management measures to alleviate risk, including water storage, alternative sources, and reduced use of resources.
5. The adoption of advanced low-water or water-free cooling systems that align with the adopted Drought Management Plan of the Metropolitan Water Services Department.
E. An energy consumption and sustainability plan including the energy load before construction of the data center and the projected daily operational load once constructed shall be submitted. This assessment shall demonstrate:
1. Estimates of peak electricity demand and strategies for mitigating strain on local power infrastructure.
2. Estimates of proposed improvements and alternatives to minimize the need for additional transmission lines from the designated power provider.
3. The use of sustainable alternatives for power generation, such as solar panels, small-scale wind turbines, or other renewable energy sources that will offset at least 10% of total power usage.
4. A decommissioning plan for unsold or surplus data infrastructure, for recycling all on-site electronic infrastructure through certified recyclers that follow Responsible Recycling (R2) Standard for Electronics Recyclers and/or e-Stewards® Standard for Responsible Recycling and Reuse of Electronic Equipment.
5. Planned use of sustainable practices to limit or offset the data center’s use of power and water.
F. A lighting plan demonstrating that there will be no light trespass from the site onto surrounding properties, including any right-of-way.
G. Transmission line impact assessment: a transmission line impact assessment shall identify the need for new or upgraded transmission lines to meet the data center’s electricity requirements. This assessment shall include the potential environmental impact on public land, including tree removal from county-owned land and rights-of-way. This assessment shall also include information on any planned substation’s location and shall show the required screening mechanism(s).
H. Any additional information requested by any reviewing department or agency shall be submitted prior to approval of the zoning permit.
I. The operator of a data center shall submit an annual compliance report that details any changes to, and continuation of all, assessments submitted as part of the zoning permit approval process and demonstrate compliance and monitoring of all application requirements and conditions of zoning to the zoning administrator or their designee no later than the first of January of each year.
Section 8. The Metropolitan Clerk is directed to publish a notice announcing such change in a newspaper of general circulation within five days following final passage.
Section 9. This Ordinance shall take effect upon publication of the above said notice, the welfare of The Metropolitan Government of Nashville and Davidson County requiring it.