Hi cockerhoop
If you have entered the fourth year of your IVA already, you need to get the property valued (a local estate agent will likely do this free of charge for you) to determine its current value. You then need to get a redemption statement from your mortgage company to confirm the amount you currently owe. By deducting this sum from the property value, you can determine your equity and you then apply a 75% percentage to that sum to work out what you have to pay over to the Supervisor. Note - they do give you the opportunity to pay this sum by extending your IVA by up to one year, and making monthly payments to the equivalent of the equity sum.
In answer to your last query, if this does raise enough money to pay off your creditors in full that is something to be pleased about. The purpose of an IVA is not to write off debt, it is to allow you to make contributions to your creditors which you can afford over a set time period - which in your case includes an equity release which you agreed to at the time of the creditors meeting.
Regards, Melanie Giles, Insolvency Practitioner for over 20 years.
For further details contact me at
http://www.melaniegiles.com and view my IVA blog at:
http://melaniegiles.blogs.iva.co.uk