Knox Box in Nashville: Requirements, Placement, and Permit

If you own or manage a commercial building in Davidson County, a Knox Box in Nashville is mandatory: order a box keyed to the Nashville Fire Department, mount it within three feet of the main entrance at the specified height, stock it with working keys and a completed contact card, then schedule the Fire Marshal’s Office to lock it up. After that, renew the permit every year.

Which Buildings Have to Have One

Every commercial building and tenant space in Davidson County is required to have at least one Knox Box. The requirement also applies wherever access is needed for firefighting, lifesaving, or reaching fire protection equipment, as designated by the Fire Marshal.¹ The code language sits in Section 506.1 of the Nashville and Davidson County Fire Code and reaches any structure where secured openings could slow an emergency response.²

The obligation does not end at installation. An operational permit under Section 105.5.58 requires owners to keep the contents working and the contacts current, verified each year.²¹

Ordering the Right Box

Order directly from the manufacturer at knoxbox.com or through an authorized local partner. When placing the order, specify the jurisdiction as “Nashville Fire Department.” That setting keys the box to match the master access devices Nashville crews carry.¹ A box keyed to the wrong jurisdiction cannot be opened by responding firefighters, and it will have to be replaced.

Picking a Size

Nashville does not require a specific model. Size is driven by occupancy type, hazards, and the number of keys and access items you need to store.¹ As a rough guide, the 3200 series holds about ten keys and fits smaller or single-tenant spaces, while the 4400 series holds up to fifty keys and suits multi-tenant or larger buildings. Access cards take up interior room and reduce the key count.

Multi-tenant, multi-story, and mid-size to larger commercial buildings need an appropriately sized series. Think about the building’s future use when picking the model, because a property likely to add tenants may need a larger box from day one.¹ Nashville has no rule on color or style, and both surface-mounted and recessed models are acceptable.

Lead Time and Price

Every Knox Box is built to order. Standard processing runs five to ten business days once the manufacturer receives the order, followed by three to five business days of shipping. Rush orders typically ship within 48 hours, though orders of five or more units may take longer, and unique department requirements can add time regardless of shipping choice.³

A standard 3200 series surface-mount box generally runs around $500. Larger models and Knox Padlocks cost more. Build in shipping and any accessories when you budget, and order well ahead of any certificate of occupancy deadline.

Where to Mount It

Placement rules are precise, and inspectors check them.

Height

The bottom of the box must sit no lower than four feet above the door threshold, and the top no higher than five and a half feet above it. The Fire Department prefers installations closer to the five-and-a-half-foot mark.¹

Horizontal Location

The box must be within three feet of the principal entrance door, or within three feet of another entrance approved by the Fire Department. It has to be on the side of the building facing the street of address unless the department approves a different location. If it will live on an exterior wall, verify the model is rated for outdoor use and follow the manufacturer’s mounting instructions.¹

Gates

If the property has manually controlled pedestrian or vehicle gates that block a fire lane or fire department access to the building, install a Knox Padlock on those gates instead of a separate Knox Box. The padlock must be rated for exterior use.¹ The requirement covers driveways, courtyards, and pedestrian walkways alike when a security gate could delay response.²

What Goes Inside

Unless the department directs otherwise, the box should contain:¹

Keys to every door and area emergency responders would need to reach. Each key must be tagged with a legible description of what it opens.
Electronic access devices such as cards or fobs for electronically controlled entry points.
Elevator keys, if the building has elevators.
A spare key for the fire alarm control panel, annunciator panel, and pull station, when applicable.
A completed Nashville Fire Department Knox Box Contact Card listing primary and secondary contacts. The department provides this card after accepting your permit application. Print it, cut it out, and laminate or sleeve it to protect it from deterioration.

Test every key and access card before the lock-up. Dead fobs or keys that no longer fit the locks mean scheduling a second visit.

Scheduling the Lock-Up

Once the box is mounted, contact the Nashville Fire Marshal’s Office to arrange the inspection and lock-up. The office can be reached at 615-862-5230 or FMORequests@nashville.gov.⁴ A fire official will confirm the box meets the height, placement, and street-facing rules, then secure the keys and contact card inside using the department’s master key.

Property owners cannot open or relock the box themselves. If a key stops working later, or you rekey a lock after the initial lock-up, you will need another visit to swap the contents.

The Annual Permit

Nashville requires an annual Knox Box permit from the Fire Marshal’s Office to verify the stored keys still work and the emergency contacts remain accurate.¹ Buildings change. Tenants turn over, locks get rekeyed, and access card systems get upgraded. A box full of outdated keys leaves crews forcing entry anyway, and you absorb the damage.

Keep an internal log of what is in the box, and review it whenever building access changes. When something is out of date, call the Fire Marshal’s Office to schedule a visit so a fire official can swap the item.

Tamper Switch Option

Tamper switches are permitted but not required in Nashville.¹ The 3200 series offers a tamper-alert version that wires into an existing alarm system on a maximum of 24 volts. A qualified alarm technician should handle the wiring, which must run through the back plate before the box is bolted to the wall and cannot pass behind the mounting bracket or between the bracket and the sidewall.⁵

1
Nashville.gov. Knox Box Information and Requirements
2
UpCodes. Nashville and Davidson County Fire Code – Knox Box
3
Knox Company. Online Orders Terms and Conditions
4
Nashville.gov. Fire Marshals Office
5
Knox Company. KnoxBox 3200 Tamper Alert Installation Instructions