Why this particular system pays for itself
Every other part of a smart home delivers comfort and savings. Leak protection delivers something different: it prevents an event that costs more than the entire smart home. A burst flexible hose under the sink floods your apartment and two below overnight. You pay for your neighbours' repairs yourself, and that is tens of thousands of dollars, not thousands.
The main mistake
Installing sensors without motorised valves. A sensor that can only beep saves you in exactly one situation: you are home, awake, and close enough to hear it. At night, at work or on holiday it is useless. The point of the system is not detection but shut-off.
How it works properly
Sensors sit on the floor where water will appear first: under the sink, behind the toilet, by the washing machine and dishwasher, near risers and by the water heater. Motorised ball valves are fitted on the cold and hot inlets. When any sensor triggers, the valves close within seconds, a siren sounds and a notification reaches your phone. The puddle stays the size of a towel.
The detail everyone forgets
A ball valve left in one position for years seizes. When it matters, the actuator simply will not turn it. So the system should cycle the valves once a month by itself — configured once and running without your involvement thereafter. If someone fits valves and does not configure that self-test, ask why.
Can it go into a finished apartment?
Yes, and it is one of the easiest systems to install in an occupied flat. The sensors are wireless and simply sit on the floor. The valves are fitted onto existing inlets — a single visit's work with a brief water shut-off.