Data centers are permitted only in the BHC, I, IP-1, IP-3, and IP-5 zones; they are not permitted in residential zones or in the BN, BG, or BD business zones.

Data centers with 15,000 square feet or less require Site Plan approval in the BHC, I, IP-1, IP-3, and IP-5 zones; they are not allowed merely as-of-right.

Data centers larger than 15,000 square feet require a Special Permit in the I, IP-1, IP-3, and IP-5 zones, in addition to Site Plan approval requirements.

The maximum gross floor area of a data center is 250,000 square feet, except in the BHC zone, where the maximum is 15,000 square feet.

A data center site must contain at least one acre.

Data centers must be at least 500 feet from any residential-zone boundary, measured by the shortest straight-line distance from the data-center building to the boundary. In the BHC zone, the requirement is at least 350 feet from any dwelling in a residential zone.

An applicant must submit a vibration and sound analysis prepared by a recognized acoustic-engineering professional who is Board Certified by the Institute of Noise Control Engineering or equivalent, and must implement the identified low-frequency-noise mitigation measures.

The data-center operator must continuously monitor sound emissions under a monitoring plan approved by the Zoning Commission, retain monitoring records for at least the previous 12 months, and provide those records to the Zoning Enforcement Officer upon request.

Large-scale blank walls visible from public view must be mitigated through architectural articulation, landscaping, or both.

A Special Permit application must include a Site Plan unless the Zoning Commission waives that requirement after finding that the proposal involves no substantial increase in site activity and no specified physical changes, such as new or expanded buildings or parking, new driveways, substantial regrading or stormwater impacts, or substantial tree clearing.

The Zoning Commission must hold a public hearing on a Special Permit application.

A Special Permit application for a data center involving more than 25,000 square feet of gross floor area must include a traffic study evaluating impacts on streets serving or affected by the development.

Data centers are permitted principal uses in the BHC, I, IP-1, IP-3, and IP-5 zones. Facilities up to 15,000 square feet require Site Plan approval; facilities from 15,001 to 250,000 square feet require a Special Permit in the I, IP-1, IP-3, and IP-5 zones. The BHC zone is limited to 15,000 square feet.

A data center in the BHC zone is protected against becoming nonconforming if a dwelling is later constructed within 350 feet of it; the later residential construction does not create a nonconformity for the existing data center. The distance is measured from the data-center building to the dwelling's principal structure.

Sustainability incentives are available to data centers because they are not single-family or duplex uses outside a subdivision. Depending on the verified sustainability score, the maximum permitted lot coverage may increase by 5%, 10%, 15%, 20%, or 25%. The sustainability elements must be maintained for the life of the project, or the project may become nonconforming.

Permeable pavement receives an impervious-coverage discount that can increase the developable site capacity of a data-center project: only 75% of the qualifying pavement area is counted toward impervious coverage. The pavement must be outside an Aquifer Protection Area, cover at least 1,000 contiguous square feet, comply with the 2024 Connecticut Stormwater Quality Manual, be maintained, and remain subject to inspection.