New Home Security First Day | What to Change First

You've got the keys. The van's outside. Somebody's already dropped a box of plates and the kettle is buried somewhere under a duvet. And somewhere in the back of your mind is the question you haven't had time to answer yet: who else has a key to this door?

That's the one hour that actually matters. Not the unpacking, not the meter readings. The security reset. Do it first, before the chaos of moving day makes you forget, and before you convince yourself you'll sort it later. Later rarely comes.

This is a field guide for that first hour. Work through it in order.

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Step One: Count the Locks You're Inheriting

Before you change anything, walk every external door and write down what you've got. You're looking for three things: what type of lock is fitted, what standard it meets, and whether it's in decent condition.

A standard Yale nightlatch on the front door is not a BS3621 deadlock. It's a convenience lock, not a security lock. If that's all you've got, your contents insurance may not pay out after a break-in. Check your policy.

The common setups in Belper properties, depending on the age:

• Victorian and Edwardian terraces (Bridge Hill, Belper town centre) tend to have older-style mortice deadlocks, sometimes Yale nightlatches. The cylinder in a nightlatch may be 20 years old with who-knows-how-many copies floating about.
• 1960s and 70s semis (Openwoodgate, Heage Road area) often have uPVC doors fitted later with a multipoint lock and a euro cylinder. That cylinder is the thing to change.
• Newer builds on the Milford and Belper Lane End side frequently come with BS-rated cylinders already, but they're not always anti-snap, and the previous owner's estate agent, cleaner, and dog-walker may have keys.
• Rented properties returning to a new tenant are the worst case. A landlord who's had three tenancies and never changed the cylinder has potentially distributed a dozen copies. If you're that landlord reading this, change the cylinder between every tenancy. It's £80 and takes twenty minutes.

Write it all down. Then move to the doors in priority order.

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Step Two: The Front Door First, Every Time

Front doors take the most attempts. Change this one before you unload the van.

If it's a uPVC or composite door with a multipoint lock, the part you're changing is the euro cylinder. That's the barrel the key goes into. Cylinders are measured by size, typically something like 35/45 or 40/50 (meaning 35mm on the inside, 45mm on the outside, measuring from the centre screw hole). Measure the old one before ordering a replacement, or call someone who'll bring the right sizes.

What to replace it with: a TS007 3-star rated cylinder as a minimum. Ultion, Avocet ABS, and Mul-T-Lock are the brands I'd fit to my own house. All of them are anti-snap, anti-pick, and anti-drill. Snap protection matters in particular because snap attacks are still the most common cylinder attack in Derbyshire, same as everywhere else. The attacker snaps the front of the cylinder off, inserts a screwdriver, and the door opens in under a minute.

A 3-star TS007 cylinder costs somewhere between £35 and £70 for the cylinder itself depending on brand. Fitting is usually £50 to £80 labour if you get someone in. That's under £150 total to properly secure your front door. Don't skip it.

If it's an older mortice deadlock on a timber door, you've got two options: rekey it (a locksmith can do this, it means changing the internal pins so old keys don't work) or replace the lock entirely with a BS3621 5-lever deadlock. If the existing lock is old, corroded, or has a keyhole on both sides with no thumbturn (which is a fire escape issue, by the way), replace it.

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Step Three: Back Door

Back doors get broken into more than front doors. Less visible from the street. Often weaker construction. Sometimes a glazed panel close enough to the lock that someone could break the glass and reach in.

Same process as the front: identify the lock type, change the cylinder or rekey the mortice.

One specific check on back doors: if there's a door chain or door bar fitted, check it's screwed into solid timber with long screws, not just into a thin bead of door frame. A chain screwed into soft pine with 20mm screws comes off with one kick. Long screws into the structural frame is what actually holds.

Also check the condition of the door itself. A composite or solid timber door with good locks but a rotten frame around the hinge side is pointless. The frame matters as much as the lock.

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Step Four: The Bits People Actually Forget

This is where most moving-day security checks fall apart. People change the front door cylinder and call it done. Then they leave three other entry points with zero thought.

The Garage

If your new house has an integral garage, that door into the house is an entry point. Burglars love integral garages because they offer cover: once inside the garage, they can work on the internal door completely out of sight.

Check the door between the garage and the house is a fire door (it should be by building regs, it's often not in older properties) and that it has a proper lock, not just a nightlatch. If it's a uPVC door with a euro cylinder, apply the same standard as your front door.

For the up-and-over or roller garage door itself: if it's remote-operated, check whether the previous owner handed over all the remotes. If you don't have confirmation of that, the simplest fix is to reprogram the remote frequency. It takes ten minutes with the manual.

If it's a manually-operated up-and-over door, check the side lock and that the internal release handle can't be reached from outside through the weather seal gap. Some older Garador and Hormann doors have a documented problem here.

Side Gate

A locked front garden and an open or flimsy side gate is a common combination. The side gate is often the route through to the back garden and back door.

Check: - Whether it's lockable at all. A bolt that shoots into a wooden post is not security, it's a suggestion. - Whether the hinges are on the outside where someone could lift it off. - Whether it's high enough that it can't simply be vaulted.

A Sold Secure rated padlock on a properly fitted hasp is a reasonable upgrade for a side gate. Something like a Mul-T-Lock padlock on a heavy hasp with coach bolts rather than wood screws. Don't fit a £12 padlock from a DIY shed on a steel hasp with wood screws; that's not deterrence, that's decoration.

Window Locks

Sash locks on uPVC windows are usually fitted as standard, but check every ground floor window and every first floor window accessible from a flat roof, extension roof, or a climbable drainpipe.

For each one: - Open the window fully and check the lock engages properly. They wear and sometimes don't catch unless you wiggle the handle. - Check whether there's a key lock as well as the main handle. Many uPVC windows have a secondary night-vent lock position that can be operated without a key. That's fine for ventilation but means the window can be opened a few inches without a key. - Sash windows in older properties often have nothing more than a sash lift or a fitch catch. A proper sash stop screwed into the frame costs a few pounds and limits how far the window opens.

Ground floor windows should all have key-operated locks. If they don't, fitting window restrictors or secondary locks is a half-day job on the whole house, and it matters for insurance.

Outbuildings and Sheds

Your power tools, bikes, and garden equipment are worth more than people think when they add it up. A decent shed hasp and a Sold Secure rated padlock. Don't fit the padlock in a position where the hasp screws are exposed when it's locked, because someone just undoes the screws.

If it's a large outbuilding with a standard up-and-over door, apply the same logic as the integral garage.

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Step Five: Check What the Previous Owner Left You

This sounds obvious. It isn't.

Go through the property and look for:

• Spare keys on hooks or in drawers. You need to know how many sets exist. Ask the estate agent or solicitor for confirmation of how many sets were in circulation. You won't always get an honest answer, which is why changing cylinders is better than relying on key collection.
• Key safes. If a key safe is fitted externally, change the code immediately. A surprising number of people don't. Key safes fitted by previous owners for care visits, Airbnb access, or estate agent viewings sometimes still have the same four-digit code for years. Check our earlier piece on key safe security for the full picture on this one.
• Alarm codes. If a burglar alarm is fitted, get the installation code from the previous owner or the monitoring company and reset it. An alarm that you don't control is not an alarm, it's a noise-maker.
• Window and door keys left in locks. Some people leave keys in window locks inside the house. That's handy for them, less useful if a burglar breaks a nearby pane and can reach in.

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Step Six: Know Your Doors

Different door types have different failure modes. If you've moved into a property with mixed door types, here's a fast reference.

Composite door with multipoint lock: Change the cylinder. Check the keep (the metal plate the bolts engage into) is solidly fixed to the frame. Check all locking points engage when you lift the handle and lock it.

uPVC door, older style: Same cylinder change. Also check the door hasn't dropped on its hinges. A dropped uPVC door puts stress on the locking mechanism and can stop the bolts fully engaging. You can see this when the door doesn't close flush at the latch side.

Timber door with mortice deadlock: Check the lock grade. It should be BS3621 5-lever. If it's a cheaper 2-lever lock (often smaller and lighter), it offers minimal security. Replace it. The cylinder on an integrated nightlatch above it should also be changed.

French doors or bifold doors: These are the weakest link in a lot of newer properties. The locking points are usually at the top and bottom of each door, operated by a lever. Check every one engages. The cylinder on the active leaf gets changed. The passive leaf, the one that usually stays locked, often has top and bottom espagnolette bolts that are easy to overlook.

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The Things That Can Wait (But Not Long)

A couple of things don't need doing in the first hour but shouldn't slip past the first week.

Security lighting. Sensor lights at the back of the house and down the side passage. Not floodlights that stay on all night and annoy the neighbours, motion-activated ones that come on when someone approaches. PIR sensors positioned to cover the gate and the back door are enough.

Postbox security. If you've got a freestanding post box or a letterbox in the front door, consider a letterbox cage on the inside of the door. This stops fishing attacks (hook on a wire through the letterbox to grab keys from a hall table) and, on composite doors with letterboxes near the handle, reduces the risk of a hook reaching the handle from outside.

Viewing the property from the outside, at night. Walk back to the pavement at 10pm and look at what's visible. This sounds slightly odd but it tells you where your lighting gaps are and what a burglar would see.

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A Word to Landlords

If you're a landlord and you've just turned a property, the same first-hour logic applies, with one addition: document what you've done. When you change a cylinder between tenancies, note the date, the cylinder brand and spec, and the number of keys issued. That's useful for insurance purposes and useful if there's ever a dispute about access.

A new Ultion cylinder with three keys and a key fob costs around £60 to £90 plus fitting. Changing it between every tenancy across your portfolio costs less per year than one claim excess. Simple maths.

Properties in Duffield, Kilburn, and Ripley with older timber doors are the ones most likely to have an undersized mortice lock. Worth checking every time the property changes hands.

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In the First Hour: The Order

If you do nothing else, do this, in this sequence:

1. Front door cylinder or lock, changed or rekeyed.
2. Back door cylinder or lock, changed or rekeyed.
3. Any other external door, including the integral garage door into the house.
4. Check all window locks operate and key-lock where needed.
5. Side gate secured.
6. Alarm code reset.
7. Locate and account for all keys left by the previous owner.
8. Change any key safe code.

Everything else builds on top of that.

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If you're in Belper or anywhere in the DE56 postcodes and you want someone to run through the first-hour checks with you, or just to change cylinders on the day you pick up the keys, give Locks Local a call. We carry common cylinder sizes in the van, we cover Belper and the surrounding DE postcodes, and most jobs we can get to in under thirty minutes. Prices are given honestly over the phone before we come out, no surprises on arrival.