Business Security

Change Business Locks by Swapping the Cylinders First

Last updated November 10, 2026 by the Louisville Car Key & Lockout editors. How we research.

You just got the keys to a storefront on Frankfort Avenue, and nobody can tell you how many copies are out there. The good news is that you almost never need new door hardware. You need new cylinders, or the old ones rekeyed.

Find Out What Kind of Lock You Have

A storefront door is simpler than it looks. A storefront parts seller's guide says the three common styles share one lock body. Two black set screws at the top press into a groove in each cylinder. That keeps a thief from unscrewing it. You loosen those screws, unscrew the cylinder, thread in the new one and seat the screw back in its channel (Door Closers USA, How to Replace a Storefront Door Lock).

That guide leaves out keys and code rules entirely. Those are the parts that cost a business money later.

Rekey, Swap the Core, or Replace

• Rekey when the hardware works and you just need old keys dead. New pins, same lock.
• Swap the core if you have many doors or a lot of staff turnover. An interchangeable core is pulled with a special control key, without taking the lock apart, so spare cores can sit on a shelf until a key goes missing (Wikipedia, Interchangeable Core).
• Replace when the lock is worn, broken, or wrong for the door, like a round knob where the code wants a lever.

If you run several doors, a master key setup can be built during the same visit, so you don't pay twice.

The Kentucky Exit Door Rule

The Kentucky Building Code is the 2015 International Building Code plus Kentucky amendments (Kentucky Department of Housing, Buildings and Construction, 2018 Kentucky Building Code, Fourth Edition). Its base rule says an exit door has to open from the inside without a key or special knowledge (International Code Council, IBC 2015 Section 1010.1.9).

There's one big exception. Offices, shops, plants, warehouses and churches may put a key lock on the inside of the main door. Three things must be true. The lock has to show plainly when it's locked. A durable sign in 1 inch letters has to sit on or next to the door, reading "THIS DOOR TO REMAIN UNLOCKED WHEN THIS SPACE IS OCCUPIED." And the building official can take that permission away for cause (IBC 2015 Section 1010.1.9.3).

That exception covers the main door only. A back door or side exit still needs to open from inside with no key. So a double cylinder deadbolt on the rear door is the wrong fix.

Kentucky's amendments touch this section in one place, and it's very Kentucky. Bourbon barrel warehouses can skip it. The owner files proof that federal security rules are met, and the padlocks come off the outside doors while people are inside (2018 Kentucky Building Code, Section 430.9.3).

Keep It Usable for Every Customer

Under the federal ADA standards, door handles, latches and locks must work with one hand. No tight grip, pinch or wrist twist, and 5 pounds of force or less. They have to sit 34 to 48 inches above the floor (U.S. Access Board, ADA Standards Sections 309.4 and 404.2.7). Kentucky's code repeats the height range for door hardware, and it lets a lock used only for security sit at any height (IBC 2015 Section 1010.1.9.2).

So when a knob fails, the new one should be a lever. A thumb turn on the inside of the main door is usually fine. A key-only inside lock is only legal under the main door exception above.

Read the Lease Before You Call Anyone

Kentucky's landlord tenant act is written for homes and apartments, as its name says (KRS 383.500). On a shop or office lease, the lease itself decides who controls the locks. Look for the alterations clause and any line saying the landlord keeps a key. Send the landlord a new key if the lease asks for one.

Louisville Business Burglaries

These are LMPD burglary reports grouped by location type, from the city's open data (LMPD Crime Data 2025, LMPD Crime Data 2026). Office buildings in 2026 are already close to their 2025 total.

Kentucky has no state locksmith license, so check whoever you hire with the locksmith vetting checklist. Ask how they'll limit copies of the new keys. The key duplication page explains which keys a hardware store can't cut.

The Rest of Your Questions

Can I change a storefront cylinder myself?

Often, yes. It's a set screw and a threaded cylinder. Test the key before you put the faceplate back, and match the cylinder length and cam to the old one.

Do I need the landlord's OK?

Check the lease. Most commercial leases treat lock changes as alterations, and many require the landlord to hold a key.

Should I rekey after a break-in?

Yes, if any keys, key cards or codes could have been taken. Do it the same day the police report is filed.

How many keys should I hand out?

As few as the work needs. Write down who holds each one, so the next change is a list, not a guess.