Rekey Or Replace? What To Do With The Locks On A House You Just Bought

Every house sale carries the same invisible problem, and almost nobody deals with it in the first month. Nobody — not you, not the sellers, not the agent — knows how many keys to your new house exist or who is holding them.

Do the arithmetic once and it stops being optional

Count the keys that plausibly exist for a house that has just changed hands. The previous owners had at least two. Their adult children had one each. A cleaner had one. A dog walker had one. The trades who prepared the house for market were given one. The listing agent had a lockbox that a dozen buyer agents opened, and every one of those visits was an opportunity nobody was watching closely.

None of those people are criminals, and that is exactly the point. You do not need bad intent for this to matter. You need one key in a drawer in a house you have never visited, held by somebody who has forgotten they have it, for years.

The answer is not paranoia. It is one hour of work in your first week.

What rekeying actually is

Inside every ordinary lock cylinder is a stack of small spring-loaded pins. Their heights are what make one key work and another not. Rekeying replaces those pins with a different combination and cuts you new keys to match. The lock body, the finish, the handle and the deadbolt all stay exactly as they are.

The moment that is done, every key that used to open the door stops working — permanently, and regardless of who is holding it or how many copies they made.

It takes ten to fifteen minutes per lock, which is why the price falls sharply as the count rises. A typical house with a front door, a back door, a garage entry and sometimes a side door is a single visit of under an hour.

When replacing is the right call instead

• The lock is worn out. A key that needs jiggling, a bolt that binds, a cylinder that turns roughly — those are mechanical failures, and rekeying a failing lock only gives you a failing lock with new keys.
• The grade is wrong. Builder-grade hardware on an exterior door is worth upgrading once, and moving day is the natural moment.
• There is no deadbolt. A knobset alone on any exterior door — especially the garage entry — is not security, it is a door catch.
• You want a keypad or smart lock. Different job, different reasons, and worth doing deliberately rather than as an afterthought.
• The lock has been forced or drilled before. Look for filled screw holes, a scarred faceplate, or a strike plate that has clearly been moved.

Ask for keyed alike, always

This is the request people forget and then wish they had made. Keyed alike means every exterior lock in the house runs on the same key: front, back, side, garage entry, and the shed if you want it.

It costs very little extra at the time of the rekey and effectively nothing afterwards, and it is the change people notice every single day — no sorting keys in the dark, no second key for the door you use least, no spare set that only opens half the house.

It is also the thing that makes the rest of your security actually get used. A back door with an awkward separate key is a back door that gets left unlocked.

The doors people forget

The front door gets attention because it is the one guests use. The doors that matter more are the ones nobody can see from the road.

The garage entry door is the standout. On most modern floor plans it leads from an attached garage into the house, and on a great many houses it carries a knobset and nothing else. Anyone inside a closed garage is invisible from the street and has unlimited time.

Then the basement walkout, the side door beside the driveway, and the door from a sunroom or deck. All of them are exterior doors. All of them deserve a graded deadbolt and a strike plate anchored with three-inch screws into the stud behind the frame.

That last detail — the screws — is the cheapest meaningful security upgrade available on any house, and it is the one we recommend most often in King City. It costs almost nothing and it changes what happens when somebody puts a shoulder to the door.