Changing the locks and other security basics when you move in

This article is for educational purposes only and is not a substitute for professional advice. Local codes, regulations, and best practices vary by region.

You don’t know how many copies of the previous owner’s keys are floating around. The contractor who built the house had keys. The real estate agent had keys. The home inspector, the appraiser, maybe the neighbor who fed the cat while the house was on the market. Everyone involved in the sale process held a key at some point. You have no idea who held what, where those keys ended up, or who might still have access to your new home.

This isn’t paranoia. This is responsibility. You don’t know these people. Some might be trustworthy. Some might not be. Some might have lost their key and never mentioned it. The only way to know for certain that only your household can get into your house is to change the locks before you move in a single box.

Rekeying Versus Replacing Locks

You have two options: rekey the existing locks or replace them entirely. Understanding the difference helps you make the right choice.

Rekeying means a locksmith changes the internal mechanism of your existing locks so they work with new keys. The lock cylinder itself stays the same. You keep the same doorknobs or lever handles. The cost is typically $50-150 per lock in most regions. If your existing locks are good quality and you like how they look and feel, rekeying is usually the smarter choice. You get the security of new keys for a lower price.

Replacing the locks means you remove the old hardware entirely and install new locks. This costs more—typically $100-300 per lock installed—but it gives you complete control over what locks you install. If your existing locks are old, worn, broken, or cheap quality, replacement makes sense. It also makes sense if you want to upgrade to better locks or change the style of your hardware.

For most new homeowners, rekeying all the exterior door locks is the right choice. It’s fast, it’s affordable, and it solves the problem. You don’t need fancy new locks; you need to be the only person with keys.

Getting Your Locks Changed

Call a locksmith and explain that you’ve just purchased the house and need all exterior door locks rekeyed. They’ll ask how many locks (count your exterior doors—front, back, side, garage). They’ll ask what type of locks you have (if you don’t know, they’ll figure it out when they visit). They’ll provide a price, usually for the whole job.

The locksmith will come to your house, change each lock, and provide you with new keys. The process takes an hour or two depending on how many doors you have. They’ll usually make multiple copies of your keys and hand them to you on the spot. You now have the only keys in existence to your locks.

You can also purchase new locks yourself at a hardware store and have the locksmith install them. This costs more but gives you complete control over quality. If you’re not sure which direction to go, ask the locksmith what they recommend for your situation. A good locksmith can guide you.

Cost for rekeying typically runs $200-500 total for a full house, depending on your region and how many doors you have. This should happen before closing if possible, or immediately after. It’s not a project to put off. Do it this week.

All Your Exterior Doors

Walk around your house and count every door that leads outside: front door, back door, side door, garage entry, basement exterior door. Each one needs to be rekeyed or replaced. Don’t miss the garage man door (the small pedestrian door on the garage, separate from the large garage door). That’s an entry point people forget.

Some people also rekey interior doors—bedrooms, bathrooms, office spaces. That’s personal preference. The priority is exterior doors. Interior rekeying makes sense if you have expensive items locked in a room, or if you’re concerned about household privacy. Otherwise, exterior security is the main issue.

Deadbolts and Secondary Locks

A deadbolt is a lock that extends a bolt deeper into the door frame than a regular lock. It’s stronger and harder to break through. Every exterior door should have a deadbolt in addition to its main lock. Many modern doors have a deadbolt on the front and back doors but not the garage entry. Check what you have.

If you don’t have deadbolts on all exterior doors, add them. A single-cylinder deadbolt costs $20-50 and takes a locksmith 15 minutes to install. You can also buy them at hardware stores and install them yourself if you’re handy—most come with simple instructions. Having a deadbolt on every exterior door is one of the cheapest, most effective security upgrades you can make.

Smart Locks and Modern Options

Some people choose to replace traditional locks with smart locks—keyed locks that also accept a numeric code, a key card, or your smartphone. These are not necessary for basic security, but they offer convenience. You don’t have to carry a physical key; you can unlock your door from your phone; you can give temporary access codes to contractors or family. They cost $200-400 per lock and require batteries or charging.

If you’re interested in smart locks, this is the time to install them. But this is an upgrade, not a requirement. Basic rekeyed locks are sufficient for security.

Additional Security Basics

Beyond changing your locks, a few other basics are worth doing immediately. Install outdoor lighting near your entrances if you don’t have it. Motion-activated lights are inexpensive and effective. They deter opportunistic break-ins and help you see who’s at your door when you answer it.

If you have a garage, close and lock it. Don’t leave it open overnight or when you’re away. A garage gives someone shelter while they work on breaking into your house.

Consider what valuables are visible from windows. Don’t leave expensive electronics, tools, or items on display where people walking by or looking through windows can see them. Close your blinds or curtains at night.

These are all basic common-sense precautions. They’re not about living in fear. They’re about making your house a less attractive target. Criminals want easy access and easy exit. If your doors are locked, your lights are on, and your garage is closed, they’ll move on to the next house.

Deadlines

Change your locks before you move in. If you can’t do it before closing, do it the day you get the keys. This is a non-negotiable first step. You may not know the history of who held keys to this house. You may not know if copies were ever made. You don’t have to know. You just have to know that as of today, only your household has access.

After 30 years in your house, you can hand off a set of original keys to the next owner with the confidence that only you and your family have ever used them.

© The Whole Home Guide