Dream about broken house key is a metaphor for a lack resources needed to satisfy your needs and desires. You are overly possessive and maybe too clingy in a relationship. You are still searching for your own identity and finding out who you are. This symbolises your inability to care for yourself or your helplessness in reaching out to others. You are in some destructive and manipulative relationship.
Broken house key dream expresses self guilt. You are literally pissed off and not expressing yourself in a positive or constructive manner. You cannot take back what has already been done. The dream is about the insults and negativity directed at you in your life. You are slowly losing your spiritual will.
If you dreamt about broken house key:
You will get frustrated by someone who has a very rigid viewpoint of the situation at hand. This person is getting frustrated with you for the exact same reason. Compassion and understanding will help soothe the tension more than aggression will.