Please make sure that whenever the door is closed the handle is lifted up and turn the key or thumb turn. This fully engages the multipoint locking system into the frame, and make sure the door is secure and draught-free.
Unless you complete step 3, your door is not fully secure.
The doors will have been fitted with a closer which closes the door automatically.
Do not interfere with or remove the door closer and make sure the door is always kept closed. Safety chain