Install a New Door Lock

In the UK, many home insurance policies mandate specific security standards, such as BS3621. Failing to meet these requirements can invalidate your cover, making a correct lock installation not just a matter of safety, but a financial necessity.

What Does the Work Involve?

• Security Survey: The locksmith assesses the door material (timber, uPVC, or composite) and frame strength to recommend the most secure lock type.
• Old Hardware Removal: Careful extraction of existing cylinders, handles, or mortice locks to prevent damage to the door face.
• Door Preparation: Measuring and cutting new recesses (morticing) or drilling holes for cylinders, ensuring the backset is perfectly aligned.
• Component Fitting: Installing the lock body, internal cylinders, and external furniture such as handles or rose plates.
• Strike Plate Alignment: Fitting the metal "keep" into the door frame, ensuring the bolt throws smoothly without sticking or rattling.
• Testing: Multiple functional checks from both sides of the door to ensure the mechanism operates flawlessly under tension.

Typical Costs

Prices for lock installation vary based on the security rating of the hardware and your location in the UK, with London and the South East typically seeing higher labour rates. The following estimates include both parts and professional labour including VAT.

The total cost is primarily influenced by the "security tier" of the lock. A basic cylinder is cheap, but a British Standard 3-star Kitemarked cylinder or a complex multi-point gearbox replacement requires a higher investment in both parts and specialist skill.

How Long Does It Take?

• Like-for-like cylinder swap: 20–30 minutes per door.
• Fresh mortice lock installation: 1–2 hours, depending on wood hardness.
• Multi-point lock gearbox replacement: 1 hour, assuming the door is correctly aligned.
• Smart lock integration: 1–1.5 hours, including app configuration and testing.

DIY or Professional?

While basic cylinder swaps on uPVC doors are possible for a confident DIYer, professional installation is highly recommended for security hardware. An incorrectly fitted lock can lead to "lock snapping" or "binding," where the mechanism fails prematurely. Most importantly, UK insurers usually require locks to be fitted to BS3621 standards; a professional locksmith provides the necessary certification and ensures the installation meets these stringent criteria to keep your policy valid.

Choosing the Right Tradesperson

• Check Qualifications: Look for locksmiths vetted by the Master Locksmiths Association (MLA) or those with an Ofqual-regulated qualification.
• Verify Identity: A reputable locksmith should carry ID and arrive in a branded vehicle.
• Ask for a DBS Check: Given the sensitive nature of the work, ensure the tradesperson has a clean, up-to-date criminal record check.
• Questions to ask: "Does this lock meet BS3621 standards?", "Is there a warranty on the mechanism?", and "Will you provide a minimum of three keys?"

UK Regulations

• BS3621: The benchmark for thief-resistant locks on timber doors. Look for the Kitemark symbol on the faceplate.
• TS007 3-Star: The standard for uPVC and composite door cylinders to prevent snapping, bumping, and picking.
• Fire Safety (Part B): For flats or HMOs, locks must often be "thumbturn" on the inside to allow escape without a key in the event of a fire.
• Part Q: Relevant for new builds, ensuring all easily accessible doors meet specific security performance requirements.

Pro Tip: Always check your home insurance "Small Print." Many UK insurers specify that all ground-floor windows and doors must have specific Kitemarked locks, or they may refuse a claim in the event of a break-in.

Common Problems

• Lock Snapping: If a Euro cylinder protrudes more than 3mm from the handle, it is vulnerable to being snapped with pliers. A pro will ensure a flush fit.
• Misalignment: If you have to "lift" the handle or "pull" the door to lock it, the strike plate is misaligned, which will eventually break the gearbox.
• Cheap Imports: Non-branded locks often lack hardened steel pins, making them easy to drill out in seconds.
• Key Duplication Issues: Some high-security locks require a code card for extra keys; ensure your locksmith explains the registration process.

Frequently Asked Questions

What is a BS3621 lock and why do I need one?

BS3621 is a British Standard for locks that can be deadlocked and the key removed from both sides. It is the "gold standard" for home security and is a mandatory requirement for most UK home insurance policies on timber exit doors.

Can I have one key for all my doors?

Yes, this is called "Keyed Alike." A locksmith can pin multiple cylinders or mortice locks to the same key profile, reducing the number of keys you need to carry without compromising security.

My uPVC door is stiff to lock, do I need a new lock?

Not necessarily. Often, the door has dropped on its hinges. A locksmith can usually realign the door for a small fee, which prevents the expensive multi-point locking mechanism from snapping.

Are smart locks as secure as traditional locks?

High-quality smart locks (like those from Yale or Ultion) are very secure and often use the same physical cylinders as traditional locks. Ensure the one you choose is "BSI IoT Kitemarked" for digital security.

Should I change the locks when moving into a new house?

Absolutely. You have no way of knowing how many spare keys were given to neighbours, tradespeople, or estate agents by the previous owners. It is the first job any new homeowner should undertake.