The most valuable thing a system gives you is knowing who can get in.
Master key systems
A master key system decides who may open which door, and records it. That record is worth more than the hardware: without it, a building eventually cannot answer how many keys exist or who holds them.
We design, install and administer these systems for buildings, offices and managed properties in Munich and the surrounding district. Pricing follows a survey — anything quoted before seeing the doors would be a guess.
Three ways a system can be built
Most enquiries begin with more complexity than the building needs. It is worth knowing the simplest form before designing past it.
Keyed alike
One key opens every door in the group. The simplest arrangement and often all a small office, a single flat with cellar and letterbox, or a workshop actually needs. No hierarchy, no administration overhead — and no way to give somebody partial access.
Master keyed
Each door has its own key, and a master key opens all of them. The standard for buildings where a caretaker or manager needs access everywhere while each tenant only reaches their own door. The hierarchy can have several levels: a departmental key below a building key below a grand master.
Central locking (Zentralschließanlage)
Every individual key also opens the shared doors — main entrance, bin store, bicycle room — while opening no other flat. This is the arrangement most German apartment buildings use, and it is why a lost flat key in such a building is a building-wide problem rather than a personal one.
How a system comes about
Foto folgt
Wie Schließanlagen — dasselbe Motiv, englischer Alt-Text
- 1
Survey
We walk the building and record every door: what is fitted now, what dimensions, which doors are fire doors, which are external. This is unglamorous and it is where systems succeed or fail. A locking plan drawn from a floor plan rather than from the doors themselves will be wrong somewhere.
- 2
The locking plan
A matrix of doors against keys, showing which key opens which door. Drawing it up is a conversation rather than a technical exercise: who genuinely needs access where, and who has it now because of a decision nobody remembers making. Most systems get smaller at this stage rather than larger.
- 3
Choosing the system
Mechanical grade, patent protection and how long the profile will remain available. Patent protection matters here more than on a single door: it is what makes uncontrolled key copying impossible, and it is the whole point of a documented system. Patents also expire, which is a question worth asking before committing a building to a profile.
- 4
Installation
Cylinders fitted, measured to sit flush, and each one checked against the plan. Every key is marked and issued against signature. The key register — who holds which key, since when — starts on day one, because starting it later means reconstructing it from memory.
- 5
Administration afterwards
Additional keys against the security card and the register. Extensions ordered against the existing plan. Departures recorded. Systems fail through administration far more often than through mechanics: a decade of untracked key issues leaves a building that cannot say who can get in.
The expensive scenario, and how to make it survivable
A lost key in a master key system is the single most costly routine event a managed building faces. The cost does not scale with the number of keys lost — it scales with how many doors that key opened, and with how well documented the system is.
A key with no record attached is the worst case: nobody can say what it opened, so the prudent response is to assume the worst and replace broadly. A key recorded in a register is a bounded problem: it opened these doors, it was held by this person, and the response can be proportionate.
This is the argument for the register, and it is worth more than the argument for any particular cylinder grade. Two things make the difference: patent protection, so keys cannot be copied at a market stall, and a register that is actually maintained rather than started and abandoned.
- Issue keys against signature, from the first day rather than the second year.
- Keep the security cards separately from the keys, and know who holds them.
- Record returns as carefully as issues — an unreturned key is only visible if the issue was recorded.
- Ask how long the profile will stay available before committing a whole building to it. Extending a discontinued system is its own expensive problem.
Questions about master key systems
What does a lost key cost in a master key system?
Far more than a single cylinder, which is exactly why it is worth planning for. In a master key system every cylinder is matched to a shared key hierarchy — so a lost key that opens the main entrance can compromise the whole system, and restoring security can mean replacing every affected cylinder rather than one. The cost scales with the number of doors, not with the number of lost keys. Systems with a documented key register and controlled duplication limit the damage, because it is then clear which key was lost and what it actually opened.
Have the building looked at
We survey first and quote afterwards. A price named before seeing the doors would be a number, not an offer.