How do I childproof exterior doors?

Neighbors Ask

The short answer, then the long one

The simplest answer is to put something between a curious toddler and the door that a toddler cannot do, but any adult can do without thinking. That usually means a lock set high on the door, a chime that announces movement, and a household habit of keeping the deadbolt thrown whenever the family is home. None of those is exotic, and most of them cost very little compared with the worry they remove.

What makes this tricky is that a front door is also your emergency exit. Anything that slows a child will, in a smoke filled hallway, slow you too, and that is the trade off to keep in mind with every choice below. So the goal is not to make the door hard to open for everybody. The goal is to make it hard for a three year old and easy for a tired parent carrying a laundry basket in one arm.

In this column we will walk through the options one at a time, explain how each really works, and say plainly where each one falls short. If you finish reading and still are not sure what suits your door, the guidance near the end on what to ask a professional should help you shape the question.

Why children and doors are such a pair

Small children learn by copying, and nothing is more copyable than a grown up turning a knob and walking outside. A lever handle is especially easy because it needs only a downward push, which even a determined two year old can manage. Round knobs are slightly harder, but a child who has watched you do it a hundred times will figure out the twist soon enough.

The deadbolt matters more than the handle. A handle latch is built to be opened from the inside by anyone, which is exactly what you want in an emergency. A deadbolt, on the other hand, usually needs a deliberate turn of a thumb piece or a key. If the deadbolt is thrown, a wandering child has two separate things to figure out instead of one.

It also helps to remember that the door is only one of the ways out. Sliding doors, back doors to a deck, and the door between the house and the garage all count. A plan that handles only the front door leaves three other doors that a determined child can reach, so think about all of them together when you walk through the house.

Start with the lock you already have

Before buying anything, spend ten minutes with the hardware you own. Check that the deadbolt actually throws all the way into the strike, and that the door closes without you having to lift or shove it. A door that sags slightly may leave the bolt only half engaged, which gives a child a head start and gives a burglar the same one. Our piece on why doors sag explains the cause.

Next, look at which side of the door has the thumb turn. On most homes the inside of the deadbolt has a small knob you turn with your fingers. That knob sits at an adult's hand height, which is a bit above a toddler's reach in the early years but within it by around age four or five. Knowing that timeline helps you decide whether you need extra measures now or later.

Then check the strike plate and the screws holding it. Short screws in a thin plate are common in older houses. Replacing them with longer ones that bite into the framing makes the door stronger and also keeps it from rattling open when a child leans on it. This is a small repair, and a locksmith or a handy neighbor can do it in one short visit.

Options that put the control out of reach

The most common solution is a second lock mounted high on the door, well above where a child can stretch. This can be a slide bolt, a chain style latch, or a small flip lock. An adult reaches up and releases it with one hand. A child, even a climbing one, usually cannot. Choose something with a smooth, obvious motion so that in a hurry nobody has to think about how it works.

A second option is a lever cover or knob cover, which is a plastic sleeve that spins freely unless you squeeze it in the right way. These work well on interior doors and on some exterior doors, but they can be awkward for guests and for anyone with weak hands. Be honest about who else lives in or visits your house before you rely on one of them.

A third option is a keyed deadbolt on the inside, which needs a key to turn from either side. This is strong against children but carries a real risk in emergencies, because you must find the key in a hurry. Whether that is appropriate for your home depends on local rules and on who lives with you, so ask before choosing it and do not leave the key out of sight.

Alarms, chimes and gentle warnings

Sometimes the right childproofing is not a barrier but a signal. A chime does not stop a toddler from touching the door, but it tells you within a few seconds that something has changed, and most small children who open a door step through slowly the first time. That pause is your window to get there.

Alarms are especially useful for doors you cannot see from the main living area, such as a back door off a utility room or a sliding door in a bedroom. They are also useful for children who sleepwalk or wake before the grown ups do. A chime on the bedroom door and another on the exit door gives you two chances to notice.

The weak point of alarms is the same as most gadgets: they depend on batteries and on people not switching them off because the sound is annoying. Pick a tone you can live with and set a reminder on your phone to check them. A system you disable is no system at all.

• A simple door chime that sounds when the door opens tells you a child has moved without needing to lock anyone in.
• A battery door alarm that mounts on the frame works the same way and is easy to remove when you move.
• A pool or yard style alarm may be worth considering if there is water or a road beyond the door.
• A smart lock or sensor can send a notice to your phone when the door moves, if you are comfortable with that technology.
• Whatever you choose, test it monthly and replace the batteries before they fade, because a dead alarm gives you a false feeling of safety.

Sliding doors, garage entries and back doors

Sliding glass doors deserve a special mention because their latches are often the weakest hardware in the house. The typical latch is a small hook on the frame that a child can lift or slide open with some effort. A dowel or bar in the track stops the door sliding, and a high mounted secondary lock stops it being opened by a child. Our sliding door questions cover this in more depth.

The door between a house and an attached garage is another place where children can get into trouble, because the garage holds tools, chemicals and a car. Many homes use a regular keyed entry set there, which locks from the outside but not always from the inside. Check that the inside has a thumb turn at an adult height and that the door self latches, which means it closes and locks without you doing anything.

Back doors that lead to a deck, a porch or a yard with steps need the same attention as the front. A child who can open a back door can fall, wander, or reach a gate. For country properties in this part of California, with long driveways and open land, the risk is not only the door but the gate beyond it, so think about the whole path from bedroom to road.

Keeping a way out for adults and for emergencies

A word of caution before you add a second lock. Every barrier you add to an exterior door slows an adult too, and in a fire or other emergency a few seconds matter. Whatever you add should be something every adult in the house can operate in the dark, with no key, and without looking. If a babysitter or grandparent stays over, show them exactly how it works.

Rules about door hardware and exits vary by city, by county and by type of building. Rentals, multi family buildings and rooms used for child care may have additional requirements that do not apply to a single family house. We cannot tell you what applies to your property, so ask your landlord, your local building office or a professional before making a permanent change. Do not remove or block an exit on the strength of advice from a column.

One more practical point. If you cannot get out of your own house with ease because of a lock, you are less safe, not more. Test your own routine. Pretend the lights are out and the alarm is blaring, then see whether you can reach and open the door with a child on your hip. If you cannot, adjust the setup until you can.

Habits matter as much as hardware

It is easy to forget that the most effective childproofing is a routine. Throw the deadbolt every time you come in. Put the key somewhere a child cannot reach, but where an adult can find it by feel. Keep shoes and bags away from the door so that a child does not have a reason to head over. A calm, consistent household beats a house full of gadgets.

Talk with children about doors in plain language. Even a toddler understands a short rule if you say it the same way every time, such as that doors stay shut unless a grown up opens them. Older children can learn to lock up behind themselves, and that habit will serve them for life, including when they carry their own keys.

If you have a visitor who often leaves a door ajar, from a delivery person to a relative, treat it like any other hazard and mention it kindly. Many families put a small sign or a hook near the door as a gentle reminder. A friendly note is more effective than a lecture, and it keeps the household on the same page.

When to call a professional

A professional can help in several situations. If your deadbolt does not throw cleanly, if the door does not seat properly, or if the strike plate is loose, a technician can adjust or replace those parts. If you want a particular type of lock added, such as a thumb turn at a higher position or a lock that works with a keypad, a visit is the easiest way to be sure the hardware suits your door. See our overview of home lock service and new lock installation.

When you describe the job, say how old your children are, how many doors you want to deal with, and whether anyone in the house has a physical limitation. That helps the technician suggest something that works for the whole family rather than just for the youngest child. You can also use the request form on our contact page to describe your door and ask what would suit it.

If your concern is a house you have just moved into, remember that you do not know who has a key. A rekey at the same time as the childproofing changes means one visit covers both. Our guide to rekeying after buying a house goes through that decision.

A simple plan you can follow this weekend

Here is a practical sequence. First, walk the house and list every door that leads outside. Second, check each door for a working deadbolt and a snug fit. Third, choose one extra layer for each door, whether a high slide lock, a chime, or a cover, depending on how your child behaves. Fourth, practice leaving the house the way you would in an emergency and fix anything that slows you down.

Then revisit the plan as the child grows. A three year old needs one set of barriers and a seven year old needs another. A child who has learned to climb onto furniture will reach locks that a smaller sibling cannot. Look over the doors at each birthday, or at the start of each season, so the setup keeps pace with the child.

If you are not sure about any step, ask. A neighbor who has been through it, a landlord who knows the building, or a technician who has seen many doors can usually give you a sensible answer over a short chat. Good childproofing is not complicated, but it does reward a little attention to detail.

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