Technically it is illegal for you to live together if you are not married. You would also not be able to sponsor your partner and your children, which would mean that they wouldn't be able to reside with you permanently, nor be able to access proper medical care etc. They wouldn't get issued with an ID number or a residents visa, and this would put huge restrictions on them, ie, schools etc.
You may find that your company wouldn't provide anything for them by way of your salary package, such as schooling, medical, flights etc. Your company may only chose to provide accommodation for you as a single person etc. over 4 years ago