A very useful system is masterkeying and keying alike lock cylinders, where multiple locks are required to be operated with the minimum of keys. On a simple level a homeowner may want their front and back door locks to be keyed alike to save having two different keys. This means that both locks are keyed alike, and share the same key, so one key can operate either door. Many upvc french doors (double doors) have a keyed alike cylinder in each door. Linacre Locksmiths often get asked to do this for homeowners who need locks changed due to lost or stolen keys for example.
However this advantage of keying alike locks is also useful to landlords who may have 3 or 4 bedrooms let out to students for example. Each student wants to lock their own door of course and also have a key to the entrance doors. Which means normally one key for front door, one key for back door and one key for their room. Three keys. Why not just have one! Here is an example of a simple masterkeying and keying alike lock suite.
The house has four bedroom doors, with front and back entrance doors. These entrance doors have been keyed alike (the same). As can be seen, the landlord has 3 master keys which can operate every lock in the house. But the students have their own keys which can do only their own bedroom but also either entrance door.
A similar suite is in the following picture. However in this instance the landlord also wanted 3 keys that just operate the entrance doors only. This is so they can give a tradesperson one of these keys (for instance a gas boiler service engineer) so they can enter the property to do the work but not be able to access any bedrooms. Again the entrance doors are keyed alike, and again the tenant has a key that does their own room and entrance doors but no other. The landlord has master keys which can operate every door.
These are simple examples of course but are ideal for landlords with a house of multiple occupancy. There are many higher levels of masterkeying and keying alike such as those found in hotels for example. Locks can be grouped into sub-groups each with their own master keys, and with a set of grand master keys to open them all.
Linacre Locksmiths can provide this service and the benefits to homeowners and landlords is obvious.