Thank you Supremewarrior!
So here are the mechanics in summary:
-There is a day to night system implemented in the game.
-Depending on the location and house, the doors lock at a certain time.
-If it is a magic door you need to use a spell (Will reveal this bit in time) to remove the barrier.
-If door is not magical or barrier has been removed and has been locked you have the option of picking the lock.
-Depending on the difficulty of the lock system, the purple bar on the left will increase in size or decrease in size.
-When the smaller silver bar goes over the purple bar simply press enter to unlock the door. It is a mini game based on timing. Mistime things and your lock pick will break. Good thing they are cheap to buy!
-Once the door has been unlocked you have the option of opening it.
There you go, hope that was informative.