Non-mols are usually granted for 6 months or a year, after which time they can be renewed if necessary.
As you've discovered, refuges have their advantages and their disadvantages but, overall, I hope you've benefitted from your stay.
However, given your future intention, you'd be foolish to give up the right to buy and, in the interests of your dc, you're best advised to put any additional security measures in place and move back to your home asap.
Don't worry too much about obtaining a non-mol before you move back as the fact is that, should he come to your home without your prior knowledge/consent, the police will advise him to leave and will no doubt arrest him if he doesn't comply.
The difference with a non-mol is that, if found to be in breach, he could be required to account for himself to whichever Court made the order, but in practise this tends not to happen where 'power of arrest' is attached.
Use something's guide to practical security measures and liaise with the police/WA to have these installed as a matter of urgency and also adopt their sensible advice with regard to keeping a diary, having no contact with your ex other than that which may be conducted through solicitors, don't hesitate to call 999 if you feel any need to do so, and apply for a non-mol if he attempts to harass you in any way.
I hope you'll come back to your thread with a positive update in the near future - remember, this board is open 24/7 should you need any advice/encouragement.
Many congratulations 
on having detached yourself from an abusive twunt and I have no doubt the future is going to be so much more fulfilling and rewarding for you than the past.