While double cylinder deadbolts (those deadbolts on house doors that require a key from both sides) can be good for security, it could be a trade-off with safety if needing to get out of the house in a hurry. In some places housing safety code requires entrances and exits can be operated from the inside without any special skills or equipment (eg. a key), while in other places this is not required or it is only required for X amount of entrances and exits.

In cases where these types of deadbolts are permitted and chosen for their security benefits, what are some ways to make that entrance/exit safer for those indoors in case of fire or some other need to get out of the house?


It's all about keys. If you need a key to open the door, make sure you'll have a key when needed. You need several of each key, aside from the one on your keychain. Your life is worth spending the extra couple bucks on keys.

Here's where the keys fit, from most used to least used:

Keyring key: This stays on your keyring like every other key you've ever used. It's your day to day egress key, often used in conjunction with a car.

Convenience key: Keep this key in the door most of the time, except when gone. This works best with an entry alarm you can arm at night, if you'd like to keep the key in overnight, which isn't a bad idea unless you have extra security needs than normal. A hook on a wall a few feet from the door can hold this key.

Aux key: keep another key on a hook by the door. Not right next to it, where it can be reached/fished from the window, but close to it. This is for guests and absent minded residents to lock/unlock the door when nobody else is around and the convenience key is out. It's also the key you give to house-sitters when you go on vacation.

Think of one belonging to the door (a knob), and one being a floater. You can combine the above two if you don't have a lot of company/family. The main point of two non-keyring keys is to avoid practical situations in which you're w/o a handy key, or tempted to touch the emergency key.

Emergency key: Keep a key under the inside doormat. You can also use a Command(tm) hook or nail halfway from floor to knob to hold such a key, so long as it's available from a crawl. This is for fire/emergency use only, don't ever lend it out or misplace it, and remind any overnight guests where it's located. A red key or tag can help avoid mix ups; you DON'T want to be surprised that someone never gave it back...


The way to mitigate the safety risks is to not use a key inside. It doesn't provide any protection, anyway, so there is no good reason to use that type of lock; it is inherently unsafe even if locally allowed.

  • The vast majority of break-ins don't involve picking locks, sawing through deadbolts, cutting arm holes in the door, or using other fancy, slow methods. The goal is to get in and out as fast as possible, and burglars look for easy opportunities. Your real protection comes from encouraging the burglar to look somewhere else.

    Doors that are not security doors, that have locks with short deadbolts, and don't have any reinforcement at the weak points, take only seconds to simply break the door open, deadbolt and all. That's what burglars look for and try; an inside key is irrelevant.

    If you make that difficult, your typical burglar will look for another house that's an easier target after a couple of unsuccessful tries. If they've specifically targeted your house, the door isn't the only, or necessarily easiest, route in. For example, they can bust out a window. Focusing on an inside key is looking in the wrong place for security.

    There are lots of ways to make a door more difficult to break open. There's tons of advice online on simple things you can do.

  • There's only one type of door where an inside key might even be a consideration -- a door with decorative glass within easy reach of the lock mechanism. That invites breaking the glass to reach the lock inside as an easy first step. If they find no lever on the inside, step 2 is the brute force option they would have tried anyway.

    If that's the type of door you have, and why an inside key seems relevant, the better solution is to get a different door. The appearance of a potentially easy way in might be what makes your house an attractive target in the first place.

Keep in mind that your property is insured against theft, and burglars rarely break in when someone is at home. So an inside key jeopardizes your own safety, doesn't offer real protection against break-in, and would be there to protect property that's insured.

  • 1
    Interesting consideration. Can you provide a link to your stats on break-in methodology? From what I've personally witnessed, the "little window" method was used 2/5 times. Would they have moved on to the foot? Possibly, but as you note, it's easy to make a door hard to kick in. Around here, we all have lil windows...
    – dandavis
    Oct 8 '17 at 20:17
  • The reason I ask is because I do have the type of door with glass within reach of the lock mechanism, which is the door that requires an indoor key.
    – cr0
    Oct 8 '17 at 20:50
  • Rather than replacing a whole door, we're considering installing a deadbolt that only needs a key from the outside, but on a part of the door harder to reach from the door glass. That way normally we have the safer lock and we wouldn't use the original deadbolt that needs a key from the indoors, and we'd only use the original when we're away for a while as extra security
    – cr0
    Oct 8 '17 at 20:51
  • 1
    @dandavis, my initial exposure was being a break-in victim myself. I got my first education from the police who investigated and the contractor who replaced the door (his specialty). Since then, I've had a general interest and have talked with many people in law enforcement who see it daily, and contractors who do the fixing afterward or specialize in security. I've also looked at extensive material online over the years. So the answer was written from a "cumulative" perspective rather than specific statistics. Common thread: people breaking in look at your house differently than you do.
    – fixer1234
    Oct 8 '17 at 21:16
  • 1
    @cr0, I saw your other question with the picture of the door. It's a problem. The new deadbolt will be an improvement, but the door, itself, looks attractive to break in. It's from an era when people often didn't even lock their doors. If it was my own house, I would replace the door. If not, look at ways to reinforce it. Maybe screw a piece of Lexan on the inside behind the windows, which could be framed to look like part of the door. Reinforce the door jamb with a metal strip. Use very long hardened screws to fasten the striker plate solidly into the framing, etc.
    – fixer1234
    Oct 8 '17 at 21:17

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