Making an exterior door stronger: frames, strike plates, hinges and deadbolts

Updated November 10, 2026 · KeystoneProGuide editorial team

Why does the door matter as much as the lock?

Because doors are how most break-ins happen. In the Bureau of Justice Statistics' survey data for 2003 to 2007, damaging or removing a door was the most common type of entry in forcible and attempted forcible burglaries. The King County Sheriff's Office in Washington State says most burglars enter through the front, back or garage door, and that even the strongest, most efficient lock will not keep out a determined burglar if it is placed in a weak door. The lock industry's own standard says the same in its way: the residential deadbolt standard warns that real-world results vary with installation and door and frame construction.

So a better door starts with the parts around the lock.

What do police recommend for the door itself?

Three police departments that publish door advice agree on the basics.

• Solid doors. Radnor Township police in Delaware County recommend a solid core or metal door for every entrance. The King County sheriff says exterior doors should be metal or solid hardwood at least 1 3/4 inches thick, in frames of equally strong material, with each door fitting its frame securely.
• Exterior doors only. Lower Moreland Township police in Montgomery County say to use properly installed solid or metal exterior doors and never interior doors, which are not as strong.
• A good fit. Lower Moreland police add weather stripping where a door does not fit tightly. ALOA, the locksmiths' trade association, says badly installed weather stripping can itself push a door out of alignment, so it needs fitting with care.

What makes the frame and strike plate stronger?

Longer screws, by every police source read for this guide. The strike plate is the metal plate on the frame that the bolt slides into.

• Radnor police recommend a heavy-duty strike plate with four screws, using 3 inch screws that reach into the wooden door frame.
• The King County sheriff gives the same specification: a four-screw strike plate with screws at least 3 inches long.
• Lower Moreland police say to anchor the strike plate to the framing of the house with 3 inch screws.

Alignment matters too. ALOA says poor door alignment is the cause of most lock problems, and that when a door drops on worn hinges or a frame shifts, the latch may no longer engage the strike properly. A strong strike plate helps only if the latch and bolt still meet it, which is why ALOA looks at alignment first.

What about the lock and hinges?

• A deadbolt with a one-inch throw. Radnor and King County both recommend a heavy-duty deadbolt whose bolt extends 1 inch, plus a knob lockset with a dead-latch. Lower Moreland police say every exterior door needs a deadbolt because a knob lock alone is not enough.
• Single-cylinder deadbolts. The King County sheriff recommends single-cylinder deadbolts on exterior doors.
• Hinges. The sheriff says hinges should be on the inside of the door or have non-removable pins.
• Double doors. For exterior double doors, the sheriff recommends steel flush bolts at the top and bottom of the inactive door, with at least a one-inch throw.

How should you see who is at the door?

With a viewer rather than a chain. The King County sheriff says a peephole or wide-angle viewer is safer than a door chain for identifying visitors. Radnor police recommend a wide-angle 160 degree peephole mounted no higher than 58 inches. Radnor also says to make sure no one can reach through an open window and unlock the door, which matters for doors with glass beside or in them.

Who does this work, and what does it cost?

A locksmith can do much of it. ALOA lists installing and repairing frames, doors and door hardware among locksmith services, and says on its hiring page that locksmiths can advise on door frames and doors as well as locks; that is the association's description of its members' work.

The cost surveys give national prices. Angi lists door hardware upgrades such as handles, deadbolts and strike plates at $25 to $150 per item. HomeAdvisor gives $50 to $200 to install a deadbolt, including labor and materials, and $125 to $175 for a mortise lockset.

Does door work need a permit?

Hardware work usually does not; replacing a door may need a check. Pennsylvania's building code regulation leaves repairs and non-structural alterations outside the code unless a local ordinance says otherwise, and says a minor framing change needed to replace an existing door is not a structural change. Ask your township or borough before enlarging an opening. In Philadelphia, a property on the city's historic register needs Historical Commission review to replace a door, storm door or security door.

Where next?

Lock grades and ratings explains what to look for in the lock itself, sliding doors, windows and garage entries covers the other ways into a house, and local businesses are on the locksmiths directory page.

Sources

1. Doors and locks, King County Sheriff's Office
2. Burglary Prevention Tips, Radnor Township Police Department
3. Prevent Burglaries with these tips from Chief Smith!, Lower Moreland Township Police Department
4. Victimization During Household Burglary (press release), Bureau of Justice Statistics
5. Common Lock Issues: Advice and Info, ALOA Security Professionals Association
6. How to Hire a Professional Locksmith, ALOA Security Professionals Association
7. What Services Does A Locksmith Provide?, ALOA Security Professionals Association
8. How Much Does a Locksmith Cost? [2026 Data], Angi
9. How Much Does a Locksmith Cost?, HomeAdvisor
10. 34 Pa. Code § 403.1. Scope., Commonwealth of Pennsylvania (Pennsylvania Code)
11. Get approval for work to a historic property, City of Philadelphia
12. ANSI/BHMA A156.40 Residential Deadbolts, Builders Hardware Manufacturers Association