It’s pretty common for me to inspect a home with a double cylinder deadbolt on the exterior doors.  This is a deadbolt that requires a key to unlock the door from both the outside and the inside of the house.  A single cylinder deadbolt requires a key to open it from the outside but there’s just a thumb latch at the inside of the house.

The International Residential Code is very clear that these double cylinder deadbolts aren’t allowed.  Section 311.2 says, “Egress doors shall be readily openable from inside the dwelling without the use of a key or special knowledge or effort.”  So no key is allowed, even if you hang it on a hook next to the door.  There can’t be any kind of touchpad keyless lock, because that would require special knowledge of the combination.

It’s important that you be able to get out of the house quickly and easily in an emergency.  It’s also important that your family, friends, acquaintances, guests, visitors, and anybody else who’s there be able to get out of the house quickly and easily in an emergency.  And keep in mind that during an emergency people often freak out.  So putting a key near the door might not help – you might forget about it if smoke is filling your house, and for a guest who isn’t familiar with the key finding it during an emergency freak-out might be impossible.

The reason for installing a double cylinder deadbolt is usually security.  It can be quite easy for an intruder to break some nearby glass and reach around to open the thumb latch on a single cylinder deadbolt.  This door is a great example, and that’s why they’ve installed a double cylinder deadbolt.  Of course, they’ve also left the key in the lock, so really what’s the point here?

I always recommend using only single cylinder deadbolt locks.  Residential building codes generally are going to favor your personal safety (the ability to get out safely in an emergency) over security (the ability to stop someone from breaking in and stealing your laptop).  But it’s up to you to make the final decision about your house.

Inspection Overview
Why Get a Home Inspection?

Recent Posts

Multiwire branch circuit

A few years ago a friend of mine who owns an old house was telling me a story about some electrical work he was doing.  He was working on a circuit with some old wiring,

Advice for sellers

As a home inspector I help buyers look through the house they want to buy. But who’s helping the seller? Of course the seller’s real estate agent is helping, and maybe the seller has used

Plumbing pipe materials

Here’s a description of some of the primary materials that we’ve made water supply pipes and plumbing drain pipes from and their pros and cons. There are three main types of pipes. There’s the water

Where not to attach a deck ledger

As a follow-up to my recent post on ledger boards I want to add some information about why you aren’t allowed to attach a ledger board to any kind of overhanging part of a house.

Request Inspection

More Posts You May Find Interesting

Multiwire branch circuit

November 21st, 2023|Comments Off on Multiwire branch circuit

A few years ago a friend of mine who owns an old house was telling me a story about some electrical work he was doing.  He was working on a circuit with some old wiring,

Advice for sellers

November 10th, 2023|Comments Off on Advice for sellers

As a home inspector I help buyers look through the house they want to buy. But who’s helping the seller? Of course the seller’s real estate agent is helping, and maybe the seller has used

Plumbing pipe materials

November 1st, 2023|Comments Off on Plumbing pipe materials

Here’s a description of some of the primary materials that we’ve made water supply pipes and plumbing drain pipes from and their pros and cons. There are three main types of pipes. There’s the water

Where not to attach a deck ledger

October 13th, 2023|Comments Off on Where not to attach a deck ledger

As a follow-up to my recent post on ledger boards I want to add some information about why you aren’t allowed to attach a ledger board to any kind of overhanging part of a house.

Ledger board

October 12th, 2023|Comments Off on Ledger board

The ledger board for a deck is the piece of lumber that’s attached directly to the house.  All of the deck joists then are attached to this ledger board, so the ledger board carries a

Cross connections

October 1st, 2023|Comments Off on Cross connections

Of all the utilities supplied to your house, water might be the most important.  You can be without electricity or natural gas for a long time, inconvenient as that might be.  But you have to