Which sensors for what? Inspiration

One more time

Yes, I have a lock detection.

The situation does not occur for me, yet here are some ideas in case you possibly forget your smartphone inside:

And now one more idea, which is my emergency solution: walk around the house and enter through the front door opened via a fingerprint reader.

All somehow unsmart, should one not have lock detection. Well, if the experts here have no idea, I guess I have to see what I can make myself. Thanks for the feedback.

Smartness relies on existing sensors... it has always been that way. If they are forgotten, you have to get creative and possibly take slightly less smart approaches. But I would generally take it easy. Maybe the window maker can install the contact for the closed door so "deep" that it only signals when the door is firmly pulled into the seal. That actually only happens when it is locked. If that doesn’t work, you just retrofit an EnOcean handle. That’s not 10000%, but it shouldn’t be a problem. The only annoying thing is if someone turns the handle when the door isn’t fully closed. But I already wrote about that.

I assume it’s a normal door and not a sliding-lift element or something like that...

I have now added the reed contacts after all... €1,500 for the windows and €500 for the cables (electrician). I hope that we will actually use it sometime.

Well, at least the ones at the terrace door are definitely important, as there are multiple applications. The others are then rather only for the alarm functions, etc.

I was able to clarify the situation in the meantime. Two contacts are installed each. One for the tilt alert and one detects whether the handle is closed. If not, the contact is considered open. The sliding door only has open/closed, as does the garage window.