I want to change the keys on my front door, how is this possible?

If it is a pvc door then just change the euro cylinder. If it is a timber door with a nightlatch/rim cylinder just change the rim cylinder part. If it is a sashlock then the lock case will need to be changed.

Can I fit a mortice sash lock to an interior door with a simple latch?

It wouldn't be a straight swap but you could chip out the inside of the door to take the bigger lock case. Standard latches are referred to as tubular latches and are only small face plate latches.

What types of latches and locks are available for interior doors?

A simple open and close latch is known as a tubular latch and is available in two main sizes of 2.5 inch and 3 inch. If you want to put a key on the door then you would need a mortice sash lock and these are generally 2 or 3 lever low security types. Euro cylinders can be used with a thumbturn lock case but not always ideal as a key is needed to enter an interior room each time (unless that is what required!). The bathroom lock has to work with a standard thumbturn lock, available separately.

Tubular door latch.

Tubular latch - the simplest and most popular interior door latch

Euro sashlock with thumbturn cylinder shown.

Euro cylinder lock case with a separate thumbturn cylinder.

Bathroom sashlock.

Bathroom lock cases are used with a thumbturn handle or escutcheon.

Mortice key sashlock.

Mortice sashlocks have a latch and a deadbolt, used on locking interior doors.

What types of locks and latches are available for exterior doors?

There are several types of door locks found on exterior doors.

  • Nightlatches with a rim cylinder are the most common type on a timber door and can also be used in conjunction with a deadbolt for added security.
  • Mortice sashlocks and deadbolts for timber doors have to be 5 lever BS3621 compliant for insurance purposes and are key operated. If security is required these are the door locks to use.
  • PVC and composite doors tend to be the most popular now and utilise a lock case that incorporates a euro cylinder. Turning the cylinder turns the multi-point locks around the door.

Mortice sashlock for exterior door.

5 lever mortice sashlock to BS3621 for exterior doors.

Mortice deadbolt door lock for exterior doors.

5 lever mortice deadbolt to BS3621 for exterior doors.

uPVC door lock for a upvc door.

Multi-point door lock case found on upvc doors.

Nightlatch with rim cylinder for exterior door.

Nightlatch with a rim cylinder found on timber exterior doors.

Can I use interior locks on external doors?

You can but it's not advisable as they are insecure. An exterior sashlock, for example, has 5 levers inside the lock so is more secure. An interior lock may only have 2 or 3 at best. Insurance companies always insist that BS3621 approved locks with 5 levers are used.

Can I just change the rim cylinder on my nightlatch?

Yes that can be done as all rim cylinders have a standard 'tongue' which fits into the back of any rim cylinder.

How easy is it fit a new upvc door lock?

The actual lock case is very difficult to replace as there are so many different types and this will invariably require the assistance of a professional repairs company. The actual euro cylinder is easy to fit and can be changed in two minutes.