Louisville may limit how company server rooms use and test backup generators

Status: Proposed · recommended by the Planning Commission; held in the Metro Council’s Planning and Zoning Committee, 6 October 2026 · Next: committee, listed for 20 October 2026 · Checked: 12 October 2026

Have a company server room in Louisville, or plans to expand one? Proposed rules would restrict backup generator types, outdoor testing schedules and non-emergency use. They could also bring larger server rooms under Louisville Metro’s full data center requirements.

The emergency-only wording appears to exclude demand response and peak shaving. That is our interpretation; confirm it with Louisville Metro Planning.

What it would do for an accessory data center

An accessory data center is “a Data Center that serves a Principal Use on the same lot, while subordinate in purpose to other on-site activities of the Principal Use.” It may support “the enterprise functions of the business, institution, or organization” associated with the main use, including affiliated off-site users. New Section 4.4.15 would require that it:

• serves only the business, institution or organization associated with the main use, and is not used for colocation for unrelated off-site users;
• has white space (the area for IT equipment) no larger than 25,000 square feet or 49.9% of the main use’s floor area, whichever is less;
• uses backup generators powered by propane, natural gas, hydrogen fuel cell, bi-fuel or battery, or classified as, or similar to, EPA Tier IV diesel (batteries may bridge the switchover);
• tests outdoor generators no more than once a week, between 8 a.m. and 5 p.m., Monday to Friday;
• uses generators for emergencies only. The text: “An emergency for purposes of this section is defined as an unexpected inadequate supply of electric energy which may result from the unexpected outage or breakdown of facilities for the generation, transmission or distribution of electric power.”

The Planning Director may approve another generator type or testing time if neighbours would not be adversely affected. A server room that does not meet these conditions is treated as a standalone data center.

The proposal’s additional noise, separation, cooling-water and utility-letter requirements would not apply to qualifying accessory server rooms. Other existing requirements may still apply.

What it would do for standalone data centers

• Up to 50,000 sq ft: permitted in listed commercial and industrial districts with special standards, or by conditional use permit. 50,001 to 500,000 sq ft: conditional use permit, M-1 district only.
• Quarter-mile (1,320 ft) separation from homes, schools, hospitals and similar uses, and from other data centers (accessory ones excluded).
• Noise from operations no more than 65 dBA or 5 dBA above the pre-construction background, whichever is less, and no more than 60 dBC from 10 p.m. to 7 a.m. (65 dBC otherwise) at the property line.
• Closed-loop systems for any water cooling; water and sewer “will serve” letters.
• The same generator rules as above.

Existing facilities: any increase in white space at a data center established before the rules take effect would have to meet them. The text does not say how an existing accessory server room is treated until it changes.

If you operate a server room or data center in Louisville, check

1. Whether your space counts as accessory, and how much white space you have against the 25,000 sq ft and 49.9% limits.
2. Your generators’ fuel and EPA tier, where they sit, and your testing schedule.
3. Whether you run generators for demand response or peak shaving, and how the emergency-only rule would treat that.
4. The committee’s action on 20 October and any amendments.

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