Hi Dave
Neverendings suggestion of a full and final settlement is a good one - and you have the perfect reason as to why this is now sensible if you could raise sufficient money.
If your current mortgage is on a repayment basis, you could look at taking out the new on on interest only. Is the house jointly owned, and is your partner also subject to the IVA? Equity release provisions do only affect your share of the equity, so there is nothing stopping your partner using some of her share to fund the extension.
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