How to Replace Locks on a New House

One of the first things to do after taking possession of a house is make sure the previous keys no longer work. You do not always need to replace every lock: if the existing deadbolts and door hardware are in good condition, rekeying may be enough. Rekeying changes the lock cylinder so the old key stops working while the existing hardware stays on the door.

Full replacement makes more sense when a lock is damaged, worn, unreliable, or when you want to upgrade to a keypad or smart lock. Start with every exterior entry door, including the door between an attached garage and the house, and reset any electronic locks or access codes left by the previous owner.

Rekey vs Replace After Buying a House

Rekeying and replacement solve the same immediate key-control problem, but replacement is not automatically necessary if the existing hardware is in good condition.

Should You Change the Locks When You Buy a House?

Yes — at minimum, you should change who has key access to the exterior doors.

A new homeowner usually has no way to know how many copies of the old keys exist. Spare keys may have been given to relatives, neighbors, cleaners, house sitters, contractors, or other people over the years.

That does not mean every lock must immediately be thrown away. The goal is to make sure keys from before your ownership no longer provide access.

If the hardware works properly, rekeying can accomplish that without replacing the entire lock. Schlage also lists moving into a new home as a common reason to rekey exterior locks.

How Soon Should You Change the Locks?

Rekey or replace the exterior locks as soon as practical after you take possession of the home.

There is no universal rule saying homeowners have exactly 24 or 48 hours to change their locks. The practical reason for doing it quickly is simple: while the old keys continue to work, you do not have full control over who may be able to enter.

If possible, plan the work in advance so you can update the locks on moving day or shortly afterward.

Which Locks Should You Change First?

Start with every keyed exterior access point.

The priority list normally includes:

• front door;
• back door;
• side doors;
• door from an attached garage into the home;
• basement exterior door;
• patio or French doors with keyed locks;
• exterior garage doors that use keys.

Detached garages, sheds, workshops, and similar structures should also be checked if their contents or access matter to you.

The door between an attached garage and the house is easy to overlook, but it is still an entry point into the living space.

If a door has both a keyed knob and a separate deadbolt, check both cylinders. Updating only one while leaving the other usable with an old key defeats much of the purpose.

Do You Need to Change Interior Door Locks?

Usually, no.

After buying a house, exterior access is the main priority. Bedroom and bathroom privacy locks normally do not need to be replaced simply because ownership changed.

Interior keyed locks may deserve attention if they protect:

• a home office with sensitive documents;
• valuable equipment;
• a room that needs controlled access;
• another area where old keys could create a problem.

For most homes, however, exterior doors should come first.

Rekey or Replace — Which Is Better?

Neither option is automatically better. The right choice depends on the condition of the existing hardware and what you want from it.

Rekey if:

• the lock operates smoothly;
• the deadbolt extends and retracts correctly;
• the hardware is not damaged;
• you like the existing style;
• your main goal is to make the old keys stop working;
• you want compatible locks to operate with the same key.

Replace if:

• the lock is worn;
• the key is difficult to turn;
• the lock repeatedly jams;
• parts are visibly damaged;
• the deadbolt is unreliable;
• you want keypad entry;
• you want a smart lock;
• you want a new finish or style;
• the existing hardware is incompatible with the key system you want.

Kwikset makes the same basic distinction in its guidance on whether to rekey or replace locks after moving: functioning hardware can often be rekeyed, while worn or unsuitable hardware is a better candidate for replacement.

What Does Rekeying a Lock Mean?

Rekeying changes the internal keying of the lock without replacing the entire lockset.

After a successful rekey:

• the lock stays on the door;
• the old key no longer works;
• a new key operates the cylinder;
• the visible hardware can remain unchanged.

This is why homeowners who say they want to “change the locks” may not actually need new hardware.

If the existing deadbolt is reliable and you are satisfied with it, rekeying may be the simpler solution.

Can You Rekey Locks Yourself?

It depends on the lock.

Some residential locks are designed for homeowner rekeying. Certain systems let you change the key using a compatible rekey tool and the current working key.

Traditional pin-tumbler cylinders may require a rekey kit, cylinder removal, or professional service.

Do not assume every lock can be rekeyed using the same procedure. Identify the brand and model first and follow its official instructions.

If you do not have the current working key, some DIY rekey systems may not work as intended.

When Should You Hire a Locksmith?

A locksmith can make sense when:

• the house has many locks;
• several different brands or key systems are installed;
• you do not have working keys;
• the hardware is unusual;
• a lock is malfunctioning;
• you want multiple compatible doors keyed alike;
• the door and strike plate need adjustment;
• you are not comfortable removing or installing the hardware.

A locksmith is not automatically required for every new home. Standard residential deadbolts and locksets can often be replaced with basic tools when the new hardware matches the existing door preparation.

Can All the Locks Use the Same Key?

Often, yes — if the locks and keyways are compatible.

A keyed-alike setup can allow one key to operate the:

• front door;
• back door;
• side door;
• garage entry door.

This can be much more convenient than carrying several nearly identical keys.

However, locks from unrelated brands or incompatible key systems cannot automatically be made to use the same key. If having one key throughout the house is important, check compatibility before buying replacement hardware.

What Tools Do You Need to Replace a Standard Door Lock?

For a straightforward replacement where the new lock fits the existing door preparation, you may need only:

• a screwdriver;
• the new lock or deadbolt;
• the manufacturer’s installation instructions;
• a measuring tape if you need to verify fit.

A drill, drill bits, or chisel may be necessary if the new hardware does not match the existing openings or strike preparation.

Replacing an existing standard deadbolt with another compatible model is usually much simpler than installing a lock into a door that has never had one.

How to Replace a Door Lock on a New House

Step 1. Keep the Door Open

Do the installation with the door open.

This gives you access to both sides of the door and prevents you from accidentally locking yourself out before you have confirmed that the new hardware works correctly.

Step 2. Remove the Existing Interior Screws

On many residential deadbolts and locksets, the main mounting screws are on the interior side of the door.

Loosen the screws and carefully separate the interior and exterior portions of the lock.

Do not assume every model is assembled identically. If something does not come apart normally, check for additional screws or consult the manufacturer’s instructions rather than forcing it.

Step 3. Remove the Latch or Deadbolt

Move to the edge of the door and remove the screws holding the latch or deadbolt faceplate.

Pull the mechanism out of the door edge.

If it does not slide out easily, make sure all fasteners have been removed before using additional force.

Step 4. Compare the New Hardware With the Existing Door

Before installing anything, confirm that the new lock fits the existing setup.

Check that:

• the latch or deadbolt fits the existing opening;
• the screw locations align;
• the hardware suits the door thickness;
• the backset is compatible;
• the exterior and interior assemblies fit properly.

This step helps prevent getting halfway through the installation before discovering that the new hardware does not fit the door.

Step 5. Install the New Latch or Deadbolt

Insert the new latch or deadbolt mechanism into the edge of the door according to the manufacturer’s orientation instructions.

Secure the faceplate.

For a deadbolt, make sure the bolt moves freely before continuing.

Do not force a part into an opening that clearly does not fit.

Step 6. Install the Exterior and Interior Components

Position the exterior cylinder or lock assembly, then align the interior portion.

Depending on the design, you may need to align:

• the cylinder;
• tailpiece or spindle;
• mounting holes;
• interior thumbturn.

Insert the mounting screws and tighten them evenly.

Do not overtighten if doing so causes the mechanism to bind.

Step 7. Test the Lock With the Door Open

This is one of the most important steps.

Before closing the door:

1. Turn the thumbturn several times.
2. Extend and retract the deadbolt.
3. Test the new key.
4. Confirm the bolt moves through its full range.
5. Make sure nothing binds or feels unusually stiff.

Only after the lock works correctly with the door open should you test it with the door closed.

Step 8. Check the Strike Plate and Door Alignment

If the deadbolt works perfectly with the door open but becomes difficult to operate when the door is closed, the problem may be alignment rather than the lock itself.

The bolt may be rubbing against the strike plate or entering the opening at an angle.

Identify where the contact occurs before modifying anything.

A sticking deadbolt does not automatically mean the new lock is defective.

Should You Replace the Strike Plate Too?

If the new lock includes a compatible strike plate, using the matching manufacturer’s components is usually sensible.

A strike plate should be repaired, repositioned, or replaced if it is:

• loose;
• damaged;
• badly aligned;
• preventing the bolt from moving properly.

However, installing a new lock does not automatically mean you need to cut a new strike location or make major changes to the door frame.

If everything aligns properly, unnecessary modification can create more problems than it solves.

What If the New House Already Has a Smart Lock?

Do more than change one PIN.

A smart lock may still contain:

• previous user codes;
• old digital keys;
• former-owner account associations;
• Wi-Fi or hub settings;
• a physical backup key cylinder.

First identify the exact brand and model. Then follow the manufacturer’s ownership-transfer or factory-reset procedure.

After the appropriate reset:

1. Connect the lock to your own account.
2. Remove or replace old access codes.
3. Create new codes.
4. Reconnect the lock to your own network or hub if applicable.
5. Check the physical backup key.
6. Rekey or replace the mechanical cylinder if necessary.

The reset procedure varies by model, so use the manufacturer’s instructions rather than a generic sequence. Kwikset maintains model-specific information in its factory reset support section.

Is Changing the Smart Lock Code Enough?

Not necessarily.

Changing one PIN does not guarantee that all previous access has been removed.

A smart lock may still have:

• other stored user codes;
• digital keys;
• app users;
• previous account associations;
• a physical key that still works.

For a lock inherited from a previous homeowner, an appropriate ownership or factory reset is generally a better starting point than changing only the most obvious code.

The mechanical backup cylinder needs separate attention if it uses a physical key.

What About Garage Door Openers?

Garage access is another part of the handover that is easy to forget.

Check:

• handheld remotes;
• wireless keypad codes;
• smart garage accounts;
• connected apps;
• programmed vehicle controls.

Old remotes can remain paired with the opener even after the house changes owners.

Use the manufacturer’s instructions for the exact garage door opener to erase old access and program your own remotes and codes.

What Other Access Should You Reset After Moving In?

Besides door locks, review any other system that can provide access to the property:

• smart lock users;
• keypad codes;
• garage remotes;
• garage keypad codes;
• gate remotes or codes;
• alarm access codes where applicable.

The goal is the same in each case: credentials from before your ownership should no longer provide access.

Should You Buy New Locks Before Closing?

You can choose and purchase hardware in advance if you want to have it ready for moving day.

Installation or rekeying should wait until you have possession and authorized access to the property.

Buying beforehand can be convenient, but first make sure you know what hardware is already installed and whether the replacement locks will fit the doors.

How Many Locks Should You Replace?

Do not simply count doors.

Instead, inspect every exterior keyed entry point.

A typical house may have:

• front entry;
• back entry;
• side entry;
• attached garage entry;
• basement entry;
• detached garage;
• shed or workshop.

A single door may also contain more than one keyed cylinder.

If both a keyed knob and deadbolt are regularly used, both should be considered when eliminating access through old keys.

Should You Replace a Working Deadbolt?

Not necessarily.

If the deadbolt:

• works smoothly;
• is not damaged;
• fits the door correctly;
• operates reliably;
• meets your needs;

rekeying may be enough.

Replacement becomes more attractive when the hardware is worn, unreliable, incompatible with your desired keying system, or missing features you want.

What If You Do Not Have the Old Key?

This can limit your DIY rekeying options.

Some homeowner rekey systems require the current operating key as part of the process.

Without a working key, your options may include:

• using a model-specific reset procedure where supported;
• replacing the cylinder;
• replacing the lock;
• calling a locksmith.

Do not assume every residential lock can be rekeyed without the current key.

When Is Full Replacement Better Than Rekeying?

Choose replacement when:

• the hardware is damaged;
• the lock repeatedly sticks or jams;
• the deadbolt is unreliable;
• exterior components are heavily worn;
• you want a smart lock;
• you want keypad or keyless access;
• you want a different style or finish;
• the current locks do not work with the key setup you want.

If none of those problems exist and your only concern is preventing old keys from working, rekeying may be enough.

Common Mistakes When Changing New-House Locks

Replacing only the front-door lock

The back, side, garage, and basement entries can be just as important.

Forgetting smart lock access

Changing the mechanical key does not necessarily remove electronic users or access codes.

Forgetting the physical key on a smart lock

A factory reset of the electronic system does not automatically mean the mechanical cylinder has been rekeyed.

Closing the door before testing

Always operate the lock several times while the door is open first.

Buying incompatible hardware

Check whether the replacement lock fits the existing door preparation before removing the old hardware.

Assuming every lock must be replaced

If the hardware is working properly, rekeying can be enough to eliminate access through the old keys.

New Home Lock Checklist

DIY or Locksmith?

DIY makes sense when the house has standard residential hardware, the replacement lock matches the existing door preparation, and you are comfortable using basic tools.

It can also work well with compatible homeowner rekey systems.

A locksmith may be the better option when:

• no working keys are available;
• the locks are unusual;
• many cylinders need coordinated rekeying;
• several doors need to use one key;
• hardware is damaged;
• a lock does not align correctly;
• the installation is not straightforward.

After buying a house, the important step is making sure old keys and access codes no longer work. If the existing locks are in good condition, rekeying may be all you need. Replace locks that are damaged, unreliable, or no longer meet your needs, and consider new hardware if you want keypad or smart-lock access.

Work through every exterior entry point rather than only the front door, reset any electronic locks and garage access left by the previous owner, and always test a newly installed lock several times with the door open before relying on it.