How to Change Locks on a House: DIY Steps, Costs, and When to Call a Locksmith

Moving into a new home is a whirlwind of boxes, yet the most critical update isn’t the paint color—it is securing who has access. Until you commit to changing locks on a new house, it is impossible to know if a neighbor, contractor, or previous resident still holds a working spare key. Establishing this security boundary is the first real step to truly feeling at home.

While many assume this task requires a professional, you don’t need to pay a typical $150 locksmith service fee to upgrade your safety. With just a single screwdriver and twenty minutes, you can successfully change locks on a house yourself. This guide breaks down the choice between rekeying and replacing, detailing the costs and steps for a simple DIY lock change that protects both your wallet and your family.

Rekeying vs. Replacing: Which Security Path is Right for You?

Moving into a new home or losing a set of keys triggers an immediate need for security, but that doesn’t always require buying brand-new hardware. Think of rekeying like changing your email password, while replacing is like buying a whole new computer. When you rekey, you keep your existing handles and deadbolts, but the internal pins are swapped so old keys no longer work. This allows you to change house keys securely while saving up to 70% of the cost of new hardware.

However, keeping your old hardware only makes sense if it is strong enough to protect you. Residential locks use a grading system (ANSI) to rate durability: Grade 3 is basic “good” security, Grade 2 is “better,” and Grade 1 is the “best” commercial-level protection. If your current deadbolt feels flimsy or is a lower-grade unit, you should replace the door locks your home security relies on to upgrade your protection level.

To settle the rekeying vs replacing locks debate, use this simple checklist:

• Rekey if: Your locks work smoothly, are high quality, and you simply want to restrict access.
• Replace if: The hardware is rusted, you want a modern finish, or you need to upgrade to a higher security grade.

Essential Tools and Measurements: How to Avoid the ‘Wrong Part’ Headache

Nothing kills a Saturday afternoon project faster than returning to the hardware store because your new lock doesn’t fit. Before you look up how to replace a door lockset, you must determine your door’s “backset,” which is simply the distance from the edge of the door to the center of the keyhole. Most residential doors rely on one of two standard measurements: 2 3/8 inches or 2 3/4 inches. While many modern locksets are adjustable to fit both, knowing this number beforehand ensures you pick compatible hardware for your specific setup.

Standard doors are typically between 1 3/8 and 1 3/4 inches thick, but older homes might have thinner panels that require a spacer kit. Once you confirm these dimensions, gathering your gear is simple since most DIY door lock replacement projects avoid power tools entirely.

• Tape measure: To confirm backset and thickness.
• Phillips-head screwdriver: Usually the only tool required for installation.
• New hardware kit: Matched to your specific measurements.

With your measurements confirmed and tools ready, you can confidently remove the old hardware.

Step-by-Step: Swapping Out Your Deadbolt in 20 Minutes

Unscrewing the old hardware is straightforward, but the real work begins when you slide the new bolt assembly into the door edge. This component, often marked with a clear “Up” arrow, serves as the anchor for the entire system and must be oriented correctly for the lock to function. When installing front door mechanisms, pay close attention to the faceplate on this bolt; it should sit flush against the wood surface without wobbling to ensure a secure fit.

Insert the exterior cylinder so that the flat metal bar, known as the tailpiece, slides horizontally through the center slot of the bolt you just installed. This bar acts like a driveshaft, transferring the turning motion of your key directly to the locking mechanism. When you replace front door lock sets, ensuring this tailpiece remains flat—rather than twisted or angled—guarantees that the key will turn smoothly without jamming or breaking off inside the cylinder later on.

Securing the interior thumbturn completes the assembly on the door, but resist the urge to crank the mounting screws down with maximum force. Over-tightening typically pinches the internal springs, resulting in a stiff or “sticky” lock that feels cheap despite being brand new. Once the door hardware is hand-tight, turn your attention to the doorframe to install the final component: the strike plate. This metal plate acts as the “socket” for the bolt, and using the new one ensures a tight seal that prevents the door from rattling.

Always perform your initial test with the door open to avoid accidentally locking yourself out. Throw the bolt back and forth a few times to confirm the motion feels fluid and the bolt extends fully. With the physical labor complete and your home secure, you might wonder if this DIY effort was worth the time compared to hiring a pro, or if there are hidden financial trade-offs to consider.

Budgeting for Security: DIY Costs vs. Professional Locksmith Fees

Financial transparency is the primary benefit of handling this upgrade yourself. When you decide to replace locks, you pay the shelf price, often securing high-quality “bump proof” models—which resist special keys used by burglars to force cylinders open—for only a $10 premium. In contrast, the cost of hiring a locksmith includes a mandatory “roll charge” or service fee just to arrive at your home, followed by per-door labor costs and potential markups on the hardware they provide.

• DIY Investment: $20–$50 per lock (Hardware only)
• Professional Investment: $75–$150 service call + $20–$30 per cylinder (Labor)

Hiring a locksmith to change house locks is certainly convenient, but the premium buys time, not necessarily better security. While saving over $100 per door is attractive, there are specific scenarios where the hardware is too complex for a standard screwdriver. Identifying these “hard mode” situations early ensures you don’t waste money on parts you cannot install.

When to Call a Pro: Identifying ‘Hard Mode’ Security Situations

While it is usually easy to swap out deadbolt hardware, older homes often feature “mortise” locks, recognized by a wide metal plate on the door edge. Disassembling this heavy box is risky, as internal springs often dislodge like clock parts. Structural misalignment creates similar risks; if you are fixing a jammed door lock that only latches when you lift the handle, the frame is likely warped. A professional can adjust the hinges so the bolt glides smoothly, whereas a new lock will simply bind up in the same spot.

“Master Key” setups also demand expert intervention, particularly if you want a single key for yourself and a restricted key for guests. This requires complex internal pinning that store-bought kits cannot support. Hiring a locksmith for new house projects with these specific constraints prevents you from compromising your security with a faulty configuration. Once you confirm your situation doesn’t require these specialized fixes, you can proceed to the final verification of your work.

Your Final Security Check: Ensuring the ‘Solid Thud’ of Success

Taking control of your front door transforms a house into a sanctuary. You no longer need to wonder who has spare keys; by upgrading home entry security yourself, you establish absolute ownership. Listen for the “solid thud” of the bolt engaging—that is the sound of real peace of mind.

Before finishing your security checklist, perform a 30-second audit. Aim for “One-Turn Ease”—if the key struggles to change the lock position, slightly adjust the alignment until it glides.

• Bolt throws fully?
• No jiggling required?
• Strike plate is secure?
• All family members have a working key?