Locks to change when you move in

Why the previous owner's assurance means nothing

Sellers hand over the keys they know about. The question is the keys they do not.

A house that has been lived in for a decade has issued keys to builders, decorators, a cleaner, a dog walker, a lodger, a neighbour who watered plants, an estate agent, a relative, and at least one person nobody remembers. Copies cost a few dollars and nobody logs them.

The same is true of a rental. A tenancy that ended six months ago may have produced three copies you will never hear about, and returning the key you were given proves nothing at all.

This is not a reason for suspicion of anybody in particular. It is simply that the key list is unknown and unknowable, and there is one cheap action that makes it known.

Rekey, and the list becomes exactly the keys you hold.

Every door, including the ones you forget

Walk the outside of the property and count the ways in.

Front door. Back door. Side door. The garage service door, which is the single most forgotten entrance in this whole subject and often the weakest lock on the property. The internal door from the garage into the house, which many people leave unlocked because the garage door is closed.

The basement hatch or cellar door. The side gate, if it has a lock, because a gate is what stops somebody working on your back door unseen.

The shed and any outbuilding, which is where the ladder lives.

Sliding patio doors, which usually have a factory latch that is weak and sometimes can be lifted out of the track entirely.

And any window with a key lock, particularly ground floor ones.

What it should cost

Rekeying is around 20 to 40 dollars per cylinder plus one service call of 35 to 100 dollars. A house with four exterior locks lands somewhere around 150 to 250 dollars in total.

That is one visit for the whole property, which is the cheap way to do it. Calling back in three months for the garage door means paying a second service call for one cylinder.

Compare that to replacing everything, which for four doors at Grade 2 hardware runs 500 to 900 dollars fitted. Worth doing if the hardware is old or failing, and unnecessary if it is not.

Ask for one price for the whole job when you book, and mention every door on the phone so nothing gets added on the day.

Key everything alike

Ask for all the exterior doors to be rekeyed to the same key. It costs nothing extra when it is done in one visit, because the locksmith is already inside every cylinder.

The convenience is obvious. The security benefit is less obvious and larger. Houses where the back door takes a different key are houses where somebody eventually stops locking the back door, or leaves it on the latch, or hides a key outside for it.

One key removes the reason for all of that.

If the doors are different brands the keyways may not match, in which case one cylinder can be swapped so they do. Ask about it when you book rather than discovering it on the day.

The upgrade worth more than the lock

While the locksmith is at the door, ask them to look at the strike plate.

A standard strike is a thin plate held by two three quarter inch screws that reach only into the jamb, which is a thin board nailed to the framing. When a door is kicked it is almost always the jamb that splits, not the lock that breaks.

A reinforced strike box with four three inch screws driven through the jamb into the structural stud behind it is a few dollars of parts and a few minutes of work, and it changes what has to fail. Do it on every exterior door.

Do the same at the hinges. Two of the screws in each hinge replaced with three inch screws into the stud, which nobody ever does and which matters just as much.

Check the deadbolt throw while you are at it. It should extend a full inch. Less than that and it is not reaching enough material to hold.

The rest of the first week

Change any garage door opener codes and delete any paired remotes you did not receive. Most openers have a learn button that clears every stored remote at once.

Change the code on any keypad lock or key safe, including the estate agent's lockbox if one is still mounted anywhere.

If there is an alarm, get the installer code changed as well as the user code, and find out who monitors it.

Find the shutoffs while you are looking around anyway. Water, gas, consumer unit. It is the same walk.

Then save your locksmith's number. You have just found one, in daylight, without being locked out. That is the best possible time to choose one.