How To Choose The Right Replacement Lock For Your Door

Whether you’re a first time buyer of a new home, or an experienced homeowner tackling the job for the very first time, it goes without saying that replacing your first lock can be confusing. This rings especially true when it comes to choosing the right replacement lock for your door – with so many options available, it’s difficult to determine which lock is right for the job.

Not to worry, as we’re here to help. In our guide, you’ll find all the information you need to help you choose the correct replacement lock for your door. From how to identify the right type of lock through to determining the right brand for your door, replacing your lock should be swift and simple after reading our guide.

First things first – identify the lock

Begin by identifying the type of lock that your door needs. You can do this by checking for the manufacturer stamp on the face of the lock, which will begin to narrow down the number of options available for your door, from the vast amount of door locks available on the market.

You can then move on to determining the type of lock that is installed in your door. We’ve listed the most common types of locks below, which should help you to identify the type of lock to buy as your replacement:

• Mortice locks – are chiselled into the door and are typically used with wooden doors. They are sometimes referred to as sash locks.
• Rim locks – sit on the outside of the door and are usually installed onto interior doors, unless they are certified to British standards. They are sometimes referred to as nightlatches.
• Multi point locking systems – are typically used with upvc doors and have at least three locking points which lock at the same time.
• Cylinder locks – are very common and are used for both internal and external doors.

Measure your lock

Make sure you are buying a replacement lock of the right size, by taking measurements of your existing lock. The way in which you measure your lock size depends entirely on the type of lock you have.

Mortice/Sash locks

Sash locks require 5 different measurements, including:

1. The case depth – from the outer parts of the lock to the very inner parts
2. The backset – from the centre of the keyhole to the lock’s leading edge
3. The case height – the total length of the case
4. The centres – measure from the centre of the handle’s slot to the centre of the keyhole’s rounded slot
5. Finally, the length and width of the lock’s face

Rim locks/Nightlatches

It’s very simple to measure this type of lock – you will only need to take three measurements:

1. The case depth – from the outer parts to the very inner parts
2. The backset – from the face of the lock to the centre of the handle’s pivot
3. The case height – measure the height of the part of the lock that sits inside the door

Multi point locking systems

There are six measurements required to correctly measure a multi point locking system and to make sure you invest in the right replacement for your current locking system:

1. The PZ centres – from the centre of the keyhole to the centre of the follower (where the handle’s spindle sits)
2. The backset – from the centre of the keyhole to the lock’s leading edge
3. Locking distances – the distance from each of the locking points to the centre of the follower – there may be more than two measurements for this, depending on your lock
4. Lock rail length – the length of the metal strip running along the door’s edge, which holds the locking components in place
5. Lock rail width – this measurement is more important than the length, as the width can differ between different types of doors and can affect the functionality of the lock

Cylinder locks

Measuring a cylinder lock is very easy but it will help you determine the type of cylinder lock to opt for.

1. Measure from the outside edge of your door to its centre
2. Follow on by measuring from the inside edge of the door to its centre
3. Measure the door from its outside edge to inside edge to double check your first two measurements
4. If your first two measurements are equal, you will need an equal cylinder lock. If they are different sizes, you will need to buy an offset cylinder lock

Do you need a left or right handed lock?

Once you have the measurements for your replacement lock, you will need to double check whether it’s a left handed or right handed lock you need to buy. The way in which your door opens determines the hinge placement and swing direction, so it’s best to keep the lock on the same side.

Top Tip: Stand with your back to the hinges of the door and open it. If the door swings to the left, it’s a left handed door and you will need a left handed lock.

Branded or non-branded?

When you’re ready to buy your replacement door lock, you will need to decide between a branded lock or non-branded lock. Of course, the majority of branded locks will be more expensive than non-branded locks, but they do come with their benefits.

Branded locks typically come with a quality seal of approval from their customers. You will find that customers will typically stick with a brand that they have been happy with in the past, unlike with non-branded products, no matter how well made they are.

You will also be able to discover many more reviews for branded locks than you would non-branded. By being able to read reviews of the replacement lock you are thinking of buying, you will be rest assured that the lock you are buying is recommended by others who have been in your situation.

With the information in this guide, choosing your replacement door lock should be a fairly simple process. Of course, if you have any questions along the way, we’re more than happy to lend a helping hand with further advice and support.