He uses the name 'giraffe' now...
What you need to do is make the hallway detector act as 'entry exit' at night, so that during the day, with the alarm set if someone comes in through a window etc... it causes or confirms an alarm,
but at night, i.e. when you come down in the morning, it only starts the entry/exit timer as if you had just come in the front door so you can enter your code / fob.
As you have wintex this should be very simple, but I don't really fit texecom so will leave the fine details to our David Attenborough hating, TSI native wildlife.
My only caveat would be, how young are the (I assume) kids, do they currently use the alarm, will they be going down the stairs in the AM and not knowing what to do with the alarm?